Azkaban documentation!¶

What is Azkaban¶

Azkaban is a distributed Workflow Manager, implemented at LinkedIn to solve the problem of Hadoop job dependencies. We had jobs that needed to run in order, from ETL jobs to data analytics products.

See the Getting Started for more details.

Features¶

Distributed Multiple Executor
MySQL Retry
Friendly UI
Conditional Workflow
Data Triggers
High Security
Support plug-in extensions, from Web UI to job Execution
Full Authorship management system

Getting Started¶

After version 3.0, we provide two modes: the stand alone “solo-server” mode and distributed multiple-executor mode. The following describes the differences between the two modes.

In solo server mode, the DB is embedded H2 and both web server and executor server run in the same process. This should be useful if one just wants to try things out. It can also be used on small scale use cases.

The multiple executor mode is for most serious production environment. Its DB should be backed by MySQL instances with master-slave set up. The web server and executor servers should ideally run in different hosts so that upgrading and maintenance shouldn’t affect users. This multiple host setup brings in robust and scalable aspect to Azkaban.

Set up the database
Configure database to use multiple executors
Download and install the Executor Server for each executor configured in database
Install Azkaban Plugins
Install the Web Server

Below are instructions on how to set Azkaban up.

Building from Source¶

Azkaban builds use Gradle (downloads automatically when run using gradlew which is the Gradle wrapper) and requires Java 8 or higher.

The following commands run on *nix platforms like Linux, OS X.

# Build Azkaban
./gradlew build

# Clean the build
./gradlew clean

# Build and install distributions
./gradlew installDist

# Run tests
./gradlew test

# Build without running tests
./gradlew build -x test

These are all standard Gradle commands. Please look at Gradle documentation for more info.

Gradle creates .tar.gz files inside project directories. eg. ./azkaban-solo-server/build/distributions/azkaban-solo-server-0.1.0-SNAPSHOT.tar.gz. Untar using tar -xvzf path/to/azkaban-*.tar.gz.

Getting started with the Solo Server¶

The solo server is a standalone instance of Azkaban and the simplest to get started with. The solo server has the following advantages.

Easy to install - No MySQL instance is needed. It packages H2 as its main persistence storage.
Easy to start up - Both web server and executor server run in the same process.
Full featured - It packages all Azkaban features. You can use it in normal ways and install plugins for it.

Installing the Solo Server¶

Follow these steps to get started:

1. Clone the repo:

git clone https://github.com/azkaban/azkaban.git

2. Build Azkaban and create an installation package:

cd azkaban; ./gradlew build installDist

3. Start the solo server:

cd azkaban-solo-server/build/install/azkaban-solo-server; bin/start-solo.sh

Azkaban solo server should be all set, by listening to 8081 port at default to accept incoming network request. So, open a web browser and check out http://localhost:8081/ . The default login username and password for the solo server are both azkaban which is configured in conf/azkaban-users.xml in the resources folder of the solo server.

4. Stop server:

bin/shutdown-solo.sh

The solo-server installation should contain the following directories.

Folder	Description
bin	The scripts to start/stop Azkaban solo server
conf	The configuration files for Azkaban solo server
lib	The jar dependencies for Azkaban
extlib	Additional jars that are added to extlib will be added to Azkaban’s classpath
plugins	the directory where plugins can be installed
web	The web (css, javascript, image) files for Azkaban web server

Inside the conf directory, there should be three files:

azkaban.private.properties - Used by Azkaban to store secrets like Mysql password
azkaban.properties - Used by Azkaban for runtime parameters
global.properties - Global static properties that are passed as shared properties to every workflow and job.
azkaban-users.xml - Used to add users and roles for authentication. This file is not used if the XmLUserManager is not set up to use it.

The azkaban.properties file is the main configuration file.

Configuring HTTPS server (Optional)¶

Azkaban solo server by default doesn’t use SSL. But you could set it up the same way in a stand alone web server. Here is how:

Azkaban web server supports SSL socket connectors, which means a keystore will have to be available. You can follow the steps to generate a valid jetty keystore provided at here. Once a keystore file has been created, Azkaban must be given its location and password. Within azkaban.properties or azkaban.private.properties (recommended), the following properties should be overridden.

jetty.keystore=keystore
jetty.password=password
jetty.keypassword=password
jetty.truststore=keystore
jetty.trustpassword=password

And configure ssl port in azkaban.properties:

jetty.ssl.port=8443

Getting started with the Multi Executor Server¶

Database setup¶

We suggest users to opt for Mysql as Azkaban database, because we build up a few Mysql connection enhancements to facilitate AZ set up, and strengthen service reliability:

Install Mysql

Installation of MySQL DB won’t be covered by these instructions, but you can access the instructions on MySQL Documentation Site.

Set up Mysql

create database for Azkaban.:
# Example database creation command, although the db name doesn't need to be 'azkaban'
mysql> CREATE DATABASE azkaban;
create a mysql user for Azkaban. For example,:
# Example database creation command. The user name doesn't need to be 'azkaban'
mysql> CREATE USER 'username'@'%' IDENTIFIED BY 'password';
# give the user INSERT, SELECT, UPDATE, DELETE permission on all tables in the Azkaban db.
mysql> GRANT SELECT,INSERT,UPDATE,DELETE ON azkaban.* to '<username>'@'%' WITH GRANT OPTION;
Mysql Packet Size may need to be re-configured. MySQL may have, by default, a ridiculously low allowable packet size. To increase it, you’ll need to have the property max_allowed_packet set to a higher number, say 1024M. To configure this in linux, open /etc/my.cnf. Somewhere after mysqld, add the following:
[mysqld]
...
max_allowed_packet=1024M
To restart MySQL, you can run:
$ sudo /sbin/service mysqld restart

Create the Azkaban Tables

Run individual table creation scripts from latest table statements on the MySQL instance to create your tables.

Alternatively, run create-all-sql-<version>.sql generated by build process. The location is the file is at /Users/latang/LNKDRepos/azkaban/azkaban-db/build/distributions/azkaban-db-<version>, after you build azkaban-db module by
```
cd azkaban-db; ../gradlew build installDist
```

Installing Azkaban Executor Server¶

Azkaban Executor Server handles the actual execution of the workflow and jobs. You can build the latest version from the master branch. See here for instructions on Building from Source.

Extract the package (executor distribution tar.gz from build folder) into a directory after gradle build. There should be the following directories.

Folder	Description
bin	The scripts to start/stop Azkaban solo server
conf	The configuration files for Azkaban solo server
lib	The jar dependencies for Azkaban
extlib	Additional jars that are added to extlib will be added to Azkaban’s classpath
plugins	the directory where plugins can be installed

For quick start, we may directly use the Installation directory azkaban/azkaban-exec-server/build/install/azkaban-exec-server generated by gradle. we only need to change mysql username and password inside azkaban.properties:

# Mysql Configs
mysql.user=<username>
mysql.password=<password>

Then run:

cd azkaban-exec-server/build/install/azkaban-exec-server
./bin/start-exec.sh

After that, remember to activate the executor by calling:

cd azkaban-exec-server/build/install/azkaban-exec-server
curl -G "localhost:$(<./executor.port)/executor?action=activate" && echo

Then, one executor is ready for use. Users can set up multiple executors by distributing and deploying multiple executor installation distributions.

Installing Azkaban Web Server¶

Azkaban Web Server handles project management, authentication, scheduling and trigger of executions. You can build the latest version from the master branch. See here for instructions on Building from Source.

Extract the package (executor distribution tar.gz from build folder) into a directory after gradle build. There should be the following directories.

Folder	Description
bin	The scripts to start/stop Azkaban solo server
conf	The configuration files for Azkaban solo server
lib	The jar dependencies for Azkaban
web	The web (css, javascript, image) files for Azkaban web server

For quick start, we may directly use the Installation directory azkaban/azkaban-web-server/build/install/azkaban-web-server generated by gradle. we only need to change mysql username and password inside azkaban.properties:

# Mysql Configs
mysql.user=<username>
mysql.password=<password>

Then run

cd azkaban-web-server/build/install/azkaban-web-server
./bin/start-web.sh

Then, a multi-executor Azkaban instance is ready for use. Open a web browser and check out http://localhost:8081/ You are all set to login to Azkaban UI.

Set up Azkaban Plugins¶

Azkaban is designed to make non-core functionalities plugin-based, so that

they can be selectively installed/upgraded in different environments without changing the core Azkaban, and
it makes Azkaban very easy to be extended for different systems.

Right now, Azkaban allows for a number of different plugins. On web server side, there are

viewer plugins that enable custom web pages to add features to Azkaban. Some of the known implementations include HDFS filesystem viewer, and Reportal.
trigger plugins that enable custom triggering methods.
user manager plugin that enables custom user authentication methods. For instance, in LinkedIn we have LDAP based user authentication.
alerter plugins that enable different alerting methods to users, in addition to email based alerting.

On executor server side

pluggable job type executors on AzkabanExecutorServer, such as job types for hadoop ecosystem components.

We recommend installing these plugins for the best usage of Azkaban. Below are instructions of how to install these plugins to work with Azkaban.

User Manager Plugins¶

By default, Azkaban ships with the XMLUserManager class which authenticates users based on a xml file, which is located at conf/azkaban-users.xml.

This is not secure and doesn’t serve many users. In real production deployment, you should rely on your own user manager class that suits your need, such as a LDAP based one. The XMLUserManager can still be used for special user accounts and managing user roles. You can find examples of these two cases in the default azkaban-users.xml file.

To install your own user manager class, specify in Azkaban-web-server-install-dir/conf/azkaban.properties:

user.manager.class=MyUserManagerClass

and put the containing jar in plugins directory.

Viewer Plugins¶

HDFS Viewer Plugin¶

HDFS Viewer Plugin should be installed in AzkabanWebServer plugins directory, which is specified in AzkabanWebServer’s config file, for example, in Azkaban-web-server-install-dir/conf/azkaban.properties:

viewer.plugins=hdfs

This tells Azkaban to load hdfs viewer plugin from Azkaban-web-server-install-dir/plugins/viewer/hdfs.

Extract the azkaban-hdfs-viewer archive to the AzkabanWebServer ./plugins/viewer directory. Rename the directory to hdfs, as specified above.

Depending on if the hadoop installation is turned on:

If the Hadoop installation does not have security turned on, the default config is good enough. One can simply restart AzkabanWebServer and start using the HDFS viewer.
If the Hadoop installation does have security turned on, the following configs should be set differently than their default values, in plugin’s config file:

Parameter	Description
`azkaban.should.proxy`	Whether Azkaban should proxy as another user to view the hdfs filesystem, rather than Azkaban itself, defaults to `true`
`hadoop.security.manager.class`	The security manager to be used, which handles talking to secure hadoop cluster, defaults to `azkaban.security.HadoopSecurity Manager_H_1_0` (for hadoop 1.x versions)
`proxy.user`	The Azkaban user configured with kerberos and hadoop. Similar to how oozie should be configured, for secure hadoop installations
`proxy.keytab.location`	The location of the keytab file with which Azkaban can authenticate with Kerberos for the specified `proxy.user`

For more Hadoop security related information, see HadoopSecurityManager.

Job Type Plugins¶

Azkaban has a limited set of built-in job types to run local unix commands and simple java programs. In most cases, you will want to install additional job type plugins, for example, hadoopJava, Pig, Hive, VoldemortBuildAndPush, etc. Some of the common ones are included in azkaban-jobtype archive. Here is how to install:

Job type plugins should be installed with AzkabanExecutorServer’s plugins directory, and specified in AzkabanExecutorServer’s config file. For example, in Azkaban-exec-server-install-dir/conf/azkaban.properties:

azkaban.jobtype.plugin.dir=plugins/jobtypes

This tells Azkaban to load all job types from Azkaban-exec-server-install-dir/plugins/jobtypes. Extract the archive into AzkabanExecutorServer ./plugins/ directory, rename it to jobtypes as specified above.

The following setting is often needed when you run Hadoop Jobs:

Parameter	Description
`hadoop.home`	Your `$HADOOP_HOME` setting.
`jobtype.global.classpath`	The cluster specific hadoop resources, such as hadoop-core jar, and hadoop conf (e.g. `${hadoop.home}/hadoop-core-1.0. 4.jar,${hadoop.home}/conf`)

Depending on if the hadoop installation is turned on:

If the hadoop installation does not have security turned on, you can likely rely on the default settings.
If the Hadoop installation does have kerberos authentication turned on, you need to fill out the following hadoop settings:

Parameter	Description
`hadoop.security.manager.class`	The security manager to be used, which handles talking to secure hadoop cluster, defaults to `azkaban.security.HadoopSecurity Manager_H_1_0` (for hadoop 1.x versions)
`proxy.user`	The Azkaban user configured with kerberos and hadoop. Similar to how oozie should be configured, for secure hadoop installations
`proxy.keytab.location`	The location of the keytab file with which Azkaban can authenticate with Kerberos for the specified proxy.user

For more Hadoop security related information, see HadoopSecurityManager.

Finally, start the executor, watch for error messages and check executor server log. For job type plugins, the executor should do minimum testing and let you know if it is properly installed.

Property Overrides¶

Azkaban job is specified with a set of key-value pairs we call properties. There are multiple sources for deciding which properties will finally be a part of job execution. Following table lists out all the sources of properties and their priorities. Please note that if a property occur in multiple sources, then its value from high property source will be used

Following properties are visible to the users. These are the same properties which are merged to form jobProps in AbstractProcessJob.java

PropertySource	Description	Priority
`global.properties` in `conf` directory	These are admin configured properties during Azkaban setup. Global to all jobtypes.	Lowest (0)
`common.properties` in `jobtype` directory	These are admin configured properties during Azkaban setup. Global to all jobtypes.	1
`plugin.properties` in `jobtype/<jobtype-name>` directory	These are admin configured properties during Azkaban setup. Restricted to a specific jobtype.	2
`common.properties` in project zip	These are user specified property which apply to all jobs in sibling or descendent directories	3
Flow properties specified while triggering flow execution	These are user specified property. These can be specified from UI or Ajax call but cannot be saved in project zip.	4
`{job-name}.job` job specification	These are user specified property in actual job file	Highest (5)

Following properties are not visible to the users. Depending on jobtype implementation these properties are used for constraining user jobs and properties. These are the same properties which are merged to form sysProps in AbstractProcessJob.java

PropertySource Description Priority

commonprivate.properties

in jobtype directory

These are admin configured properties during Azkaban setup. Global to all jobtypes.

Lowest (0)

private.properties

in: jobtype/{jobtype-name}

Upgrading DB from 2.1¶

If installing Azkaban from scratch, you can ignore this document. This is only for those who are upgrading from 2.1 to 2.5.

The update_2.1_to_3.0.sql needs to be run to alter all the tables. This includes several table alterations and a new table.

Here are the changes:

Alter project_properties table’
- Modify ‘name’ column to be 255 characters
Create new table triggers

Importing Existing Schedules from 2.1¶

In 3.0, the scheduling system is merged into the new triggering system. The information will be persisted in triggers table in DB. We have a simple tool to import your existing schedules into this new table.

After you download and install web server, please run this command once from web server install directory:

$ bash bin/schedule2trigger.sh

Upgrading DB from 2.7.0¶

If installing Azkaban from scratch, you can ignore this document. This is only for those who are upgrading from 2.7 to 3.0.

The create.executors.sql, update.active_executing_flows.3.0.sql, update.execution_flows.3.0.sql, and create.executor_events.sql needs to be run to alter all the tables. This includes several table alterations and two new table.

Here are the changes:

Alter active_executing_flows table’
- Deleting ‘port’ column
- Deleting ‘host’ column
Alter execution_flows table’
- Adding an ‘executor_id’ column
Create new executors table
Create new executor events table

Configurations¶

Azkaban can be configured in many ways. The following describes the knobs and switches that can be set. For the most part, there is no need to deviate from the default values.

Azkaban Web Server Configurations¶

These are properties to configure the web server. They should be set in azkaban.properties.

General Properties¶

Parameter	Description	Default
azkaban.name	The name of the azkaban instance that will show up in the UI. Useful if you run more than one Azkaban instance.	Local
azkaban.label	A label to describe the Azkaban instance.	My Local Azkaban
azkaban.color	Hex value that allows you to set a style color for the Azkaban UI.	#FF3601
azkaban.depth	Graph expansion level. Zero (0) means all flows are collapsed when the graph is rendered for the first time.	2 This means the flows will be recursively expanded up to two levels down when the graph is 1st shown.
web.resource.dir	Sets the directory for the ui’s css and javascript files.	web/
default.timezone	The timezone that will be displayed by Azkaban.	America/Los_Angeles
viewer.plugin.dir	Directory where viewer plugins are installed.	plugins/viewer
job.max.Xms	The maximum initial amount of memory each job can request. This validation is performed at project upload time	1GB
job.max.Xmx	The maximum amount of memory each job can request. This validation is performed at project upload time	2GB

Multiple Executor Mode Parameters¶

Parameter	Description	Default
azkaban.use.multiple.executors	Should azkaban run in multi-executor mode. Required for multiple executor mode.	false
azkaban.executorselector.filters	A common separated list of hard filters to be used while dispatching. To be chosen from StaticRemaining, FlowSize, MinimumFreeMemory and CpuStatus. Order of filter does not matter.
azkaban.executorselector.comparator.{ComparatorName}	Integer weight to be used to rank available executors for a given flow. Currently, {ComparatorName} can be NumberOfAssignedFlowC omparator, Memory, LastDispatched and CpuUsage as ComparatorName. For example:- azkaban.executorselec tor.comparator.Memory =2
azkaban.queueprocessing.enabled	Should queue processor be enabled from webserver initialization	true
azkaban.webserver.queue.size	Maximum flows that can be queued at webserver	100000
azkaban.activeexecutor.refresh.milisecinterval	Maximum time in milliseconds that can be processed without executor statistics refresh	50000
azkaban.activeexecutor.refresh.flowinterval	Maximum number of queued flows that can be processed without executor statistics refresh	5
azkaban.executorinfo.refresh.maxThreads	Maximum number of threads to refresh executor statistics	5

Jetty Parameters¶

Parameter	Description	Default
jetty.maxThreads	Max request threads	25
jetty.ssl.port	The ssl port	8443
jetty.keystore	The keystore file
jetty.password	The jetty password
jetty.keypassword	The keypassword
jetty.truststore	The trust store
jetty.trustpassword	The trust password

Project Manager Settings¶

Parameter	Description	Default
project.temp.dir	The temporary directory used when uploading projects	temp
project.version.retention	The number of unused project versions retained before cleaning	3
creator.default.proxy	Auto add the creator of the projects as a proxy user to the project.	true
lockdown.create.projects	Prevents anyone except those with Admin roles to create new projects.	false
lockdown.upload.projects	Prevents anyone but admin users and users with permissions to upload projects.	false

MySQL Connection Parameter¶

Parameter	Description	Default
database.type	The database type. Currently, the only database supported is mysql.	mysql
mysql.port	The port to the mysql db	3306
mysql.host	The mysql host	localhost
mysql.database	The mysql database
mysql.user	The mysql user
mysql.password	The mysql password
mysql.numconnections	The number of connections that Azkaban web client can open to the database	100

Executor Manager Properties¶

Parameter	Description	Default
execution.logs.retention.ms	Time in milliseconds that execution logs are retained	7257600000L (12 weeks)

Notification Email Properties¶

Parameter	Description	Default
mail.sender	The email address that azkaban uses to send emails.
mail.host	The email server host machine.	localhost
mail.port	The email server port.	25
mail.user	The email server user name.
mail.password	The email password user name.
mail.tls	Use TLS for the connection.	false
mail.useAuth	Use authentication.	true

User Manager Properties¶

Parameter	Description	Default
user.manager.class	The user manager that is used to authenticate a user. The default is an XML user manager, but it can be overwritten to support other authentication methods, such as JDNI.	azkaban.user.XmlUserM anager
user.manager.xml.file	Xml file for the XmlUserManager	conf/azkaban-users.xm l

User Session Properties¶

Parameter	Description	Default
session.time.to.live	The session time to live in ms seconds	86400000
max.num.sessions	The maximum number of sessions before people are evicted.	10000

Azkaban Executor Server Configuration¶

Executor Server Properties¶

Parameter	Description	Default
executor.port	The port for azkaban executor server	0 (any free port)
executor.global.properties	A path to the properties that will be the parent for all jobs.	none
azkaban.execution.dir	The folder for executing working directories	executions
azkaban.project.dir	The folder for storing temporary copies of project files used for executions	projects
executor.flow.threads	The number of simultaneous flows that can be run. These threads are mostly idle.	30
job.log.chunk.size	For rolling job logs. The chuck size for each roll over	5MB
job.log.backup.index	The number of log chunks. The max size of each log is then the index * chunksize	4
flow.num.job.threads	The number of concurrent running jobs in each flow. These threads are mostly idle.	10
job.max.Xms	The maximum initial amount of memory each job can request. If a job requests more than this, then Azkaban server will not launch this job	1GB
job.max.Xmx	The maximum amount of memory each job can request. If a job requests more than this, then Azkaban server will not launch this job	2GB
azkaban.server.flow.max.running.minutes	The maximum time in minutes a flow will be living inside azkaban after being executed. If a flow runs longer than this, it will be killed. If smaller or equal to 0, there’s no restriction on running time.	-1

MySQL Connection Parameter¶

Parameter	Description	Default
database.type	The database type. Currently, the only database supported is mysql.	mysql
mysql.port	The port to the mysql db	3306
mysql.host	The mysql host	localhost
mysql.database	The mysql database
mysql.user	The mysql user
mysql.password	The mysql password
mysql.numconnections	The number of connections that Azkaban web client can open to the database	100

Plugin Configurations¶

Execute-As-User¶

With a new security enhancement in Azkaban 3.0, Azkaban jobs can now run as the submit user or the user.to.proxy of the flow by default. This ensures that Azkaban takes advantage of the Linux permission security mechanism, and operationally this simplifies resource monitoring and visibility. Set up this behavior by doing the following:-

Execute.as.user is set to true by default. In case needed, it can also be configured to false in azkaban-plugin’s commonprivate.properties Configure azkaban.native.lib= to the place where you are going to put the compiled execute-as-user.c file (see below) Generate an executable on the Azkaban box for azkaban-common/src/main/c/execute-as-user.c. it should be named execute-as-user Below is a sample approach

scp ./azkaban-common/src/main/c/execute-as-user.c onto the Azkaban box
run: gcc execute-as-user.c -o execute-as-user
run: chown root execute-as-user (you might need root privilege)
run: chmod 6050 execute-as-user (you might need root privilege)

UserManager¶

When you start Azkaban, you may notice the login page. Azkaban makes you authenticate before you can use it. This is prevent seeing or executing workflows you shoudn’t see or touch.

We also used authenticated users for auditing purposes. Whenever project files change, is modified, scheduled, etc. we often want to know which user performed that action.

user login in page:

XmlUserManager¶

The XmlUserManager is the default UserManager that is built into Azkaban. To explicitly set the parameters that configure the XmlUserManager, the following parameters can be set in the azkaban.properties file.

Parameter	Default
user.manager.class	azkaban.user.XmlUserManager
user.manager.xml.file	azkaban-users.xml

The other file that needs to be modified is the azkaban-users.xml file. The XmlUserManager will parse the user xml file once during startup to set up the users.

Everything must be enclosed in a <azkaban-users> tag.

<azkaban-users>
    ...
</azkaban-users>

Users¶

To add users, add the <user> tag.:

<azkaban-users>
   <user username="myusername" password="mypassword" roles="a" groups="mygroup" / >
   <user username="myusername2" password="mypassword2" roles="a, b" groups="ga, gb" / >
   ...
 </azkaban-users>

Attributes	Values	Required?
username	The login username.	yes
password	The login password.	yes
roles	Comma delimited list of roles that this user has.	no
groups	Comma delimited list of groups that the users belongs to.	no
proxy	Comma delimited list of proxy users that this users can give to a project	no

Groups¶

To add users, add the <group> tag.:

<azkaban-users>
  <user username="a" ... groups="groupa" / >
  ...
  <group name="groupa" roles="myrole" / >
  ...
</azkaban-users>

In the previous example, user ‘a’ is in the group ‘groupa’. User ‘a’ would also have the ‘myrole’ role. A regular user cannot add group permissions to a project unless they are members of that group.

The following are some group attributes that you can assign.

Attributes	Values	Required?
name	The group name	yes
roles	Comma delimited list of roles that this user has.	no

Roles¶

Roles are different in that it assigns global permissions to users in Azkaban. You can set up roles with the <roles> tag.:

<azkaban-users>
  <user username="a" ... groups="groupa" roles="readall" / >
  <user username="b" ... / >
  ...
  <group name="groupa" roles="admin" / >
  ...
  <role name="admin" permissions="ADMIN" / >
  <role name="readall" permissions="READ" / >
</azkaban-users>

In the above example, user ‘a’ has the role ‘readall’, which is defined as having the READ permission. This means that user ‘a’ has global READ access on all the projects and executions.

User ‘a’ also is in ‘groupa’, which has the role ADMIN. It’s certainly redundant, but user ‘a’ is also granted the ADMIN role on all projects.

The following are some group attributes that you can assign.

Attributes	Values	Required?
name	The group name	yes
permissions	Comma delimited list global permissions for the role	yes

The possible role permissions are the following:

Permissions	Values
ADMIN	Grants all access to everything in Azkaban.
READ	Gives users read only access to every project and their logs
WRITE	Allows users to upload files, change job properties or remove any project
EXECUTE	Allows users to trigger the execution of any flow
SCHEDULE	Users can add or remove schedules for any flows
CREATEPROJECTS	Allows users to create new projects if project creation is locked down

Custom User Manager¶

Although the XmlUserManager is easy enough to get started with, you may want to integrate with an already established directory system, such as LDAP.

It should be fairly straight forward to implement a custom UserManager. The UserManager is a java interface. There are only a few methods needed to implement.:

public interface UserManager {
    public User getUser(String username, String password) throws UserManagerException;
    public boolean validateUser(String username);
    public boolean validateGroup(String group);
    public Role getRole(String roleName);
    public boolean validateProxyUser(String proxyUser, User realUser);
}

The constructor should take an azkaban.utils.Props object. The contents of azkaban.properties will be available for the UserManager for configuration.

Package your new custom UserManager into a jar and drop it into the ./extlib directory or alternatively into the plugins directory (i.e. ./plugins/ldap/linkedin-ldap.jar).

Change the azkaban.properties configuration to point to the custom UserManager. Add additional parameters into azkaban.properties if needed by your custom user manager.

Parameter	Default
`user.manager.class`	`azkaban.user.CustomUserManager`

Creating Flows¶

This section covers how to create your Azkaban flows using Azkaban Flow 2.0. Flow 1.0 will be deprecated in the future.

Flow 2.0 Basics¶

Step 1:¶

Create a simple file called flow20.project. Add azkaban-flow-version to indicate this is a Flow 2.0 Azkaban project:

azkaban-flow-version: 2.0

Step 2:¶

Create another file called basic.flow. Add a section called nodes, which will contain all the jobs you want to run. You need to specify name and type for all the jobs. Most jobs will require the config section as well. We will talk more about it later. Below is a simple example of a command job.

nodes:
  - name: jobA
    type: command
    config:
      command: echo "This is an echoed text."

Step 3:¶

Select the two files you’ve already created and right click to compress them into a zip file called Archive.zip. You can also create a new directory with these two files and then cd into the new directory and compress: zip -r Archive.zip . Please do not zip the new directory directly.

Make sure you have already created a project on Azkaban ( See Create Projects ). You can then upload Archive.zip to your project through Web UI ( See Upload Projects ).

Now you can click Execute Flow to test your first Flow 2.0 Azkaban project!

Job Dependencies¶

Jobs can have dependencies on each other. You can use dependsOn section to list all the parent jobs. In the below example, after jobA and jobB run successfully, jobC will start to run.

nodes:
  - name: jobC
    type: noop
    # jobC depends on jobA and jobB
    dependsOn:
      - jobA
      - jobB

  - name: jobA
    type: command
    config:
      command: echo "This is an echoed text."

  - name: jobB
    type: command
    config:
      command: pwd

You can zip the new basic.flow and flow20.project again and then upload it to Azkaban. Try to execute the flow and see the difference.

Job Config¶

Azkaban supports many job types. You just need to specify it in type, and other job-related info goes to config section in the format of key: value pairs. Here is an example of a Pig job:

nodes:
  - name: pigJob
    type: pig
    config:
      pig.script: sql/pig/script.pig

You need to write your own pig script and put it in your project zip and then specify the path for the pig.script in the config section.

Common Parameters¶

Besides the type and the dependencies parameters, there are several parameters that Azkaban reserves for all jobs. All of the parameters below are optional.

Parameter	Description
retries	The number of retries that will be automatically attempted for failed jobs
retry.backoff	The millisec time between each retry attempt
working.dir	Override the working directory for the execution. This is by default the directory that contains the job file that is being run
env.property	Set the environment variable with named property
failure.emails	Comma delimited list of emails to notify during a failure *
success.emails	Comma delimited list of emails to notify during a success *
notify.emails	Comma delimited list of emails to notify during either a success or failure *

Email properties¶

Note that for email properties, this property is retrieved from the last job in the flow and applied flow level. All other email properties of jobs in the flow are ignored.

Flow Config¶

Not only can you configure individual jobs, but you can also config the flow parameters for the entire flow. Simply add a config section at the beginning of the basic.flow file. For example:

---
config:
  user.to.proxy: foo
  failure.emails: noreply@foo.com

nodes:
  - name: jobA
    type: command
    config:
      command: echo "This is an echoed text."

When you execute the flow, the user.to.proxy and failure.emails flow parameters will apply to all jobs inside the flow.

Flow Level Retry¶

Flow Level Retry

Embedded Flows¶

Flows can have subflows inside the flow just like job nodes. To create embedded flows, specify the type of the node as flow. For example:

nodes:
  - name: embedded_flow
    type: flow
    config:
      prop: value
    nodes:
      - name: jobB
        type: noop
        dependsOn:
          - jobA

      - name: jobA
        type: command
        config:
          command: pwd

Download Examples¶

You can download the simple Flow 2.0 project zip examples to start playing with Azkaban:

Using Azkaban¶

This section covers how to use Azkaban Web UI to create, view and execution your flows.

Create Projects¶

After logging onto Azkaban, you will see the Projects page. This page will show you a list of all the projects that you have read permissions on. Projects where only group permissions as or those with a role with READ or ADMIN will not appear.

If you are just starting out, the project page may be empty. However you can see all the existing projects by clicking on All Projects .

Clicking on Create Projects will pop open a dialog box. Enter in a unique project name and description of the project. The description can be changed in the future, but the project name cannot be. If you don’t see this button, it is likely that the ability to create new projects has been locked down except for users with the proper permissions.

After creating your project, an empty project page will appear. You will automatically be given ADMIN status for this project. Add and remove permissions by clicking on the Permissions Button.

If you have the proper permissions (which you should if you created the project), you can delete the project, update the description, upload files and view the project logs from this page.

Upload Projects¶

Click on the Upload button. You will see the following dialog.

Select the archive file of your workflow files that you want to upload. Currently Azkaban only supports *.zip files. The zip should contain the *.job files and any files needed to run your jobs. Job names must be unique in a project.

Azkaban will validate the contents of the zip to make sure that dependencies are met and that there’s no cyclical dependencies detected. If it finds any invalid flows, the upload will fail.

Uploads overwrite all files in the project. Any changes made to jobs will be wiped out after a new zip file is uploaded.

After a successful upload, you should see all of your flows listed on the screen.

Flow View¶

By clicking on the flow link, you can go to the Flow View page. From here, you’ll be shown a graph representation of the flow. The left panel contains a list of jobs in your flow.

Right clicking on either the jobs in the right panel or the nodes in the graph will allow you to open individual jobs. You are also able to Schedule and Execute Flows from this page.

Click on the Executions tab will show you all the previous executions of this flow.

Project Permissions¶

When a project is created, the creator is automatically given an ADMIN status on the project. This allows the creator to view, upload, change jobs, run flows, delete and add user permissions to the project. An admin can remove other admins, but cannot remove themselves. This prevents projects from being admin-less except when admins are deleted by a user with an admin role.

The permission page is accessible from the project page. On the permissions page, admins can add other users, groups or proxy users to the project.

Adding user permissions gives those users those specified permissions on the project. Remove user permissions by unchecking all of the permissions.
Group permissions allow everyone in a particular group the specified permissions. Remove group permissions by unchecking all the group permissions.
If proxy users are turned on, proxy users allows the project workflows to run as those users. This is useful for locking down which headless accounts jobs can proxy to. They are removed by clicking on the ‘Remove’ button once added.

Every user is validated through the UserManager to prevent invalid users from being added. Groups and Proxy users are also check to make sure they are valid and to see if the admin is allowed to add them to the project.

The following permissions can be set for users and groups:

Permission	Description
ADMIN	Allows the user to do anything with this project, as well as add permissions and delete the project.
READ	The user can view the job, the flows, the execution logs.
WRITE	Project files can be uploaded, and the job files can be modified.
EXECUTE	The user is allowed to execute, pause, cancel jobs.
SCHEDULE	The user is allowed to add, modify and remove a flow from the schedule.

Executing Flow¶

From the Flow View or the Project Page, you can trigger a job to be executed. You will see an executing panel pop-up.

Executing Flow View¶

From the Flow View panel, you can right click on the graph and disable or enable jobs. Disabled jobs will be skipped during execution as if their dependencies have been met. Disabled jobs will appear translucent.

Notification Options¶

The notification options allow users to change the flow’s success or failure notification behavior.

Notify on Failure¶

First Failure - Send failure emails after the first failure is detected.
Flow Finished - If the flow has a job that has failed, it will send failure emails after all jobs in the flow have finished.

Email overrides¶

Azkaban will use the default notification emails set in the final job in the flow. If overridden, a user can change the email addresses where failure or success emails are sent. The list can be delimited by commas, whitespace or a semi-colon.

Failure Options¶

When a job in a flow fails, you are able to control how the rest of the flow will succeed.

Finish Current Running will finish the jobs that are currently running, but it will not start new jobs. The flow will be put in the FAILED FINISHING state and be set to FAILED once everything completes.
Cancel All will immediately kill all running jobs and set the state of the executing flow to FAILED.
Finish All Possible will keep executing jobs in the flow as long as its dependencies are met. The flow will be put in the FAILED FINISHING state and be set to FAILED once everything completes.

Concurrent Options¶

If the flow execution is invoked while the flow is concurrently executing, several options can be set.

Skip Execution option will not run the flow if its already running.
Run Concurrently option will run the flow regardless of if its running. Executions are given different working directories.
Pipeline runs the the flow in a manner that the new execution will not overrun the concurrent execution.
- Level 1: blocks executing job A until the previous flow’s job A has completed.
- Level 2: blocks executing job A until the immediate children of the previous flow’s job A have completed. This is useful if you need to run your flows two steps behind an already executing flow, as opposed to Level 1 which executes one step behind. If the child node is a sub-flow, Level 2 only blocks on the immediate start node(s) inside the sub-flow. This does not wait for the entire sub-flow.
- Level 3: blocks all jobs until the previous flow has completed.

Runtime Properties¶

Runtime Properties allow users to override properties temporarily.

Note: This feature was previously known as Flow Parameters.

_images/executeflowruntimeproperties.png

The scope of each runtime property is defined by the Node selection. Rows with ROOT Node apply to all jobs in the flow. Properties can be scoped per sub-flow as well as individual jobs. Most specific node path takes precedence.

Overrides are applied depending on the Azkaban server configuration property azkaban.executor.runtimeProps.override.eager:

azkaban.executor.runtimeProps.override.eager=false (default):
- Runtime properties don’t override predefined properties from a more specific node path. In particular runtime properties at flow level don’t override predefined properties at job level.
azkaban.executor.runtimeProps.override.eager=true:
- Runtime properties (also those that are set on a parent node or at flow level) have higher precedence than predefined properties.

Executions¶

Flow Execution Page¶

After executing a flow you will be presented the Executing Flow page. Alternatively, you can access these flows from the Flow View page under the Executions tab, the History page, or the Executing page.

This page is similar to the Flow View page, except it shows status of running jobs.

Selecting the Job List will give a timeline of job executions. You can access the jobs and job logs directly from this list.

This page will auto update as long as the execution is not finished.

Some options that you are able to do on execution flows include the following:

Cancel - kills all running jobs and fails the flow immediately. The flow state will be KILLED.
Pause - prevents new jobs from running. Currently running jobs proceed as usual.
Resume - resume a paused execution.
Retry Failed - only available when the flow is in a FAILED FINISHING state. Retry will restart all FAILED jobs while the flow is still active. Attempts will appear in the Jobs List page.
Prepare Execution - only available on a finished flow, regardless of success or failures. This will auto disable successfully completed jobs.

Executing Page¶

Clicking on the Executing Tab in the header will show the Execution page. This page will show currently running executions as well as recently finished flows.

History Page¶

Currently executing flows as well as completed executions will appear in the History page. Searching options are provided to find the execution you’re looking for. Alternatively, you can view previous executions for a flow on the Flow View execution tab.

Schedule Flow¶

From the same panel that is used to execute flow, flows can be scheduled by clicking on the Schedule button.

Any flow options set will be preserved for the scheduled flow. For instance, if jobs are disabled, then the scheduled flow’s jobs will also be disabled.

With new flexible scheduling feature in Azkaban 3.3, User are able to define a cron job following Quartz syntax. One important change different from Quartz or cron is that Azkaban functions at the minute granularity at most. Therefore, second field in UI is labeled as a static “0”. The Flexible Schedule Wiki explains the details how to use.

After scheduling, it should appear on the schedule page, where you can remove the scheduled job or set the SLA options.

SLA¶

To add SLA notification or pre-emption, click on the SLA button. From here you can set the SLA alert emails. Rules can be added and applied to individual jobs or the flow itself. If duration threshold is exceeded, then an alert email can be set or the flow or job can be auto killed. If a job is killed due to missing the SLA, it will be retried based on the retry configuration of that job.

Job Page¶

Jobs make up individual tasks of a flow. To get to the jobs page, you can right click on a job in the Flow View, the Executing Flow view or the Project Page.

From this page you can see the dependencies and dependents for a job as well as the global properties that the job will use.

Job Edit¶

Clicking on Job Edit will allow you to edit all the job properties except for certain reserved parameters, such as type, and dependencies. The changes to the parameters will affect an executing flow only if the job hasn’t started to run yet. These overwrites of job properties will be overwritten by the next project upload.

Job History¶

Any retries of a job will show as executionid.attempt number.

Job Details¶

From an execution page, after clicking “Job List” and then “Details” for one of the jobs, you will arrive at the job details page. This page contains tabs for the “Job Logs” and a “Summary”.

Job Logs¶

The job logs are stored in the database. They contain all the stdout and stderr output of the job.

Job Summary¶

The Job Summary tab contains a summary of the information in the job logs. This includes:

Job Type - the jobtype of the job
Command Summary - the command that launched the job process, with fields such as the classpath and memory settings shown separately as well
Pig/Hive Job Summary - custom stats specific to Pig and Hive jobs
Map Reduce Jobs - a list of job ids of Map-Reduce jobs that were launched, linked to their job tracker pages

Conditional Workflow¶

What is Azkaban Conditional Workflow?¶

Conditional workflow feature allows users to specify whether to run certain jobs based on conditions.

Users can run or disable certain jobs based on runtime parameters like the output from previous jobs. Azkaban provides users with some predefined macros to specify the condition based on previous jobs’ status. With those conditions, users can obtain more flexibility in deciding the job execution logic. For example, they can run the current job as long as one of the parent jobs has succeeded. They can achieve branching logic inside a workflow.

Conditional workflow feature leverages Azkaban Flow 2.0 design ( see Creating Flows ). The condition is defined inside a flow YAML file.

How to define a condition?¶

A valid condition is a combination of multiple conditions on job runtime parameters and one condition on job status macro. Comparison and logical operators can be used to connect individual condition components.

Supported operators are: ==, !=, >, >=, <, <=, &&, ||, !

Condition on job runtime parameter¶

Variable substitution ${jobName:param} can be used to define the condition on the job runtime parameter. : is used to separate the jobName and the parameter. The runtime parameter can be compared with a string or a number in the condition. Users need to write the value of the parameter into the $JOB_OUTPUT_PROP_FILE ( This output file is available to most Azkaban jobs ).

Condition on job status macro¶

This condition will be evaluated on all the parent jobs, i.e. the dependsOn section in YAML file.

Currently supported macros:

all_success (default)

all_done

all_failed

one_success (at least one parent job succeeded)

one_failed (at least one parent job failed)

Corresponding job status for each macro:

all_done: FAILED, KILLED, SUCCEEDED, SKIPPED, FAILED_SUCCEEDED, CANCELLED

all_success / one_success: SUCCEEDED, SKIPPED, FAILED_SUCCEEDED

all_failed / one_failed: FAILED, KILLED, CANCELLED

Users are not allowed to combine multiple conditions on job status macros in one single condition because they might have conflict with each other.

Some valid examples¶

${JobA:param1} == 1 && ${JobB:param2} > 5
one_success
all_done && ${JobC:param3} != "foo"
(!{JobD:param4} || !{JobE:parm5}) && all_success || ${JobF:parm6} == "bar"

Sample conditional flow YAML file¶

sample.flow

nodes:
 - name: JobA
   type: command
   config:
     command: bash ./write_to_props.sh

 - name: JobB
   type: command
   dependsOn:
     - JobA
   config:
     command: echo “This is JobB.”
   condition: ${JobA:param1} == 1

 - name: JobC
   type: command
   dependsOn:
     - JobA
   config:
     command: echo “This is JobC.”
   condition: ${JobA:param1} == 2

 - name: JobD
   type: command
   dependsOn:
     - JobB
     - JobC
   config:
     command: pwd
   condition: one_success

write_to_props.sh

echo '{"param1":"1"}' > $JOB_OUTPUT_PROP_FILE

In this sample conditional workflow, JobA first writes the value of param1 into $JOB_OUTPUT_PROP_FILE. Then JobB and JobC evaluate their own conditions and see if JobA’s param1 equals to their expected value. Here JobB’s condition satisfies but JobC’s condition fails. So JobB will start to run but JobC will be canceled. Once JobB finishes, JobD will start to evaluate its condition which says one_success, meaning as long as either JobB or JobC succeeds, it will start to run.

You can define the condition for both jobs and subflows.

View condition from Azkaban web UI¶

A job or embedded flow with condition will show up with a condition tag from the flow graph page.

You can view the job condition on the job page:

Also, you can view the condition of an embedded flow in the flow summary page:

Download Examples¶

You can download the simple conditional workflow project zip example to try out this feature:

conditionalFlowProject.zip

Flow Trigger Dependency Plugin¶

Kafka Event Based trigger¶

Currently, Azkaban supports launching flows via scheduling it or Ajax API. However, they are limited because sometimes jobs need to be executed automatically on demand. Event trigger is a new feature introduced by Azkaban. It defines a new paradigm of triggering flows - triggering a flow on Kafka event arrival. This concept enables users to define events that the flow depends on. Once all of the events become ready, a workflow will be triggered.

Apache Kafka is a Publish & Subscribe data streaming system. By utilizing Kafka, we do the regular expression match on the Kafka event payload. With the contain-a logic matching, a dependency will be marked as satisfied only if the whole payload contains the Regex pattern that user predefines.

Getting Started with Deploying Event Trigger on the Azkaban¶

Azkaban builds use Gradle (downloads automatically when run using gradlew which is the Gradle wrapper) and requires Java 8 or higher.

Build¶

The following commands run on *nix platforms like Linux, OS X. For building Flow Trigger Dependency Plugin, we need to run the comment in /az-flow-trigger-dependency-type/kafka-event-trigger directory.

# Build Azkaban
../../gradlew build

# Clean the build
../../gradlew clean

# Build without running tests
../../gradlew build -x test

These are all standard Gradle commands. Please look at the Gradle documentation for more info.

Server Configuration¶

The gradlew commands help you to build the fat JAR. After that, you need to specify the plugin.dir within conf. Take solo-server for example, override the azkaban.dependency.plugin.dir property for runtime parameters inside the azkaban.properties file under the solo-server conf directory. This property needs to set to contain the location where you put your Event-Trigger JAR file.

Database Configuration¶

The following 4 properties have to be defined in conf/azkaban.private.properties. for solo-server based on the use case.

Properties
mysql.user
mysql.password
org.quartz.dataSource.quartzDS.user
org.quartz.dataSource.quartzDS.password

Event Based Trigger Plugin Configuration¶

Inside the Azkaban dependency plugin directory, there should be two items Event Based Trigger plugin jar and the dependency.properties.

Required properties are:

dependency.classpath - Used by Azkaban identify plugins classpath. Should be the JAR file’s absolute path.
dependency.class - Used by Azkaban flow trigger instance to integrate with this configuration file. Take Event trigger for example, it should be trigger.kafka.KafkaDependencyCheck.
kafka.broker.url - Specifying URL and port number where your Kafka broker is.

Event Trigger Instance Configuration¶

Event trigger is part of flow definition and each flow can only have one event trigger at most. Defining an event trigger is supported via Hadoop DSL. The trigger needs to be configured within the flow file along with the project zip that users upload. Event trigger is composed of a list of event dependencies, max wait time and schedule. Take the following figure as an example:

Max Wait Time: How long the trigger will wait for all dependencies to be available before canceling it.
Trigger.schedule: The schedule to perform this workflow on the regular basis. We use the cron time format here to specify, creating a trigger followed by the project workflow every 2 minutes
triggerDependencies: The params here are to clarify what regex pattern happening in the event coming from a specific topic channel. The trigger kick-starts the flow if all of the predefined dependency conditions are met.

Therefore, this trigger example will launch the flow once detecting Kafka event with anything in AzEvent_Topic4, .*Partition[A-Z]....Event string in event coming from AzEvent_Topic4 and hadoop?.* in AzEvent_Topic1.

The matching mechanism can be extended other than regex since now it is implemented as a generic interface.

Event Based Trigger Example with Azkaban UI¶

All scheduled data trigger will show up Azkaban Flow Trigger section. Also, project admins are able to pause and resume a scheduled trigger for an undesirable situation.

Trigger info page for a specific flow:

Current and historic triggers for a specific flow:

Follow these steps to run end to end local test:

1.Start Kafka Broker Locally:

Following Kafka QuickStart to run these Kafka console scripts in Kafka package

*Start ZooKeeper
bin/zookeeper-server-start.sh config/zookeeper.properties
*Start Kafka Server
bin/kafka-server-start.sh config/server.properties

2. Send Json event to topics with AzEvent_Topic4 as example:

bin/kafka-console-producer.sh --broker-list localhost:9092 --topic AzEvent_Topic4 < recordPartition.json

Here is how my recordPartition.json looks like:

{
    "name":"Charlie",
    "team": "Azkaban",
    "event":"MetastorePartitionAuditEvent"
}

Once this event arrived, Azkaban will mark this specific event dependency as success.

3. Send another event from producer to launch the flow:

bin/kafka-console-producer.sh --broker-list localhost:9092 --topic AzEvent_Topic4 < recordHadoop.json

Trigger the workflows that have all dependencies cleared out:

Limitation¶

Since our design purpose is to decouple the trigger condition from the action to take, currently there is a limitation on deserializing record. Although Kafka provides the ability to publish and subscribe to streams of records on custom serializer and deserializer. What we have right now is limited to Kafka build in String deserializer only. We are planning to enhance the flexibility on users to upload JAR with their own custom deserialize function in the near future.

API Documentation¶

Often there’s a desire to interact with Azkaban without having to use the web UI. Azkaban has some exposed ajax calls accessible through curl or some other HTTP request clients. All API calls require a proper authentication first.

Azkaban assumes the following request header in servlet’s isAjaxCall(HttpServletRequest request) method:

Content-Type:     application/x-www-form-urlencoded
X-Requested-With: XMLHttpRequest

However, currently for most of the APIs in this version, it is not checking the request header. Many APIs still treat a request as an ajax call if request simply contains the parameter ajax. Or even, several APIs are implicitly assuming it is an ajax call even without this keyword. For ease of use though, it is recommended to always keep the correct request header.

Authenticate¶

Method: POST
Request URL: /?action=login
Parameter Location: Request body

This API helps authenticate a user and provides a session.id in response.

Once a session.id has been returned, until the session expires, this id can be used to do any API requests with a proper permission granted. A session expires if you log out, change machines, browsers or locations, if Azkaban is restarted, or if the session expires. The default session timeout is 24 hours (one day). You can re-login whether the session has expired or not. For the same user, a new session will always override the old one.

Importantly, session.id should be provided for almost all API calls (other than authentication). session.id can be simply appended as one of the request parameters, or set via the cookie: azkaban.browser.session.id. The two HTTP requests below are equivalent:

# a) Provide session.id parameter directly
curl -k --get --data "session.id=bca1d75d-6bae-4163-a5b0-378a7d7b5a91&ajax=fetchflowgraph&project=azkaban-test-project&flow=test" https://localhost:8443/manager

# b) Provide azkaban.browser.session.id cookie
curl -k --get -b "azkaban.browser.session.id=bca1d75d-6bae-4163-a5b0-378a7d7b5a91" --data "ajax=fetchflowgraph&project=azkaban-test-project&flow=test" https://localhost:8443/manager

Request Parameters¶

Parameter	Description
action=login	The fixed parameter indicating the login action.
username	The Azkaban username.
password	The corresponding password.

Response Object¶

Parameter	Description
error	Return an error message if the login attempt fails.
session.id	Return a session id if the login attempt succeeds.

A sample call via curl:

curl -k -X POST --data "action=login&username=azkaban&password=azkaban" https://localhost:8443

A sample response:

{
  "status" : "success",
  "session.id" : "c001aba5-a90f-4daf-8f11-62330d034c0a"
}

Fetch user Projects¶

The ajax API for listing all existing projects for a user, which is the current user by default.

Notice: If the user name supplied does not exist, the call will succeed and return a document where the projects value is an empty list.

Method: GET
Request URL: /index?ajax=fetchuserprojects
Parameter Location: Request Query

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=fetchuserprojects	The fixed parameter indicating the fetch user projects action.
user (optional)	The user name for which to list projects. By default, the user for the session.id value.

Response Object 1. (if the request succeeds):¶

Parameter

Description

projects

A list of project details. Structure:

{
  "projectId": numeric,
  "projectName": string,
  "createdBy": stringUserName,
  "createdTime": numericMillis,
  "userPermissions": {},
  "groupPermissions": {}
}

Example values: [{“projectId”: 123, “projectName”: “my_project”, “createdBy” : “username”, “createdTime” : 1500671590922, “userPermissions”: {}, “groupPermissions”: {}}]

Response Object 2. (if the request fails):¶

Parameter	Description
message	The error message.
error	The error name.

Here’s a curl command sample:

curl -k -X GET https://localhost:8443/index?ajax=fetchuserprojects&user=alice&session.id=9089beb2-576d-47e3-b040-86dbdc7f523e

A sample response:

{
  "projects": [
    {
      "projectId" : 123,
      "projectName" : "alice-project",
      "createdBy" : "alice",
      "createdTime" : 1500671590922,
      "userPermissions" : [ {
        "first" : "alice",
        "second" : {
          "types" : [ "ADMIN" ]
        }
      } ],
      "groupPermissions" : [ ]
    },
    {
      "projectId" : 456,
      "projectName" : "bob-project",
      "createdBy" : "bob",
      "createdTime" : 1566255237373,
      "userPermissions" : [ {
        "first" : "bob",
        "second" : {
          "types" : [ "ADMIN" ]
        }
      }, {
        "first" : "alice",
        "second" : {
          "types" : [ "WRITE", "READ" ]
        }
      }, {
        "first" : "carol",
        "second" : {
          "types" : [ "SCHEDULE", "EXECUTE", "WRITE", "READ" ]
        }
      } ],
      "groupPermissions" : [ ]
    }
  ]
}

Create a Project¶

The ajax API for creating a new project.

Notice: before uploading any project zip files, the project should be created first via this API.

Method: POST
Request URL: /manager?action=create
Parameter Location: Request Query

Request Parameters¶

Parameter	Description
session.id	The user session id.
action=create	The fixed parameter indicating the create project action.
name	The project name to be uploaded.
description	The description for the project. This field cannot be empty.

Response Object 1. (if the request succeeds):¶

Parameter	Description
status	The status of the creation attempt.
path	The url path to redirect
action	The action that is suggested for the frontend to execute. (This is designed for the usage of the Azkaban frontend javascripts, external users can ignore this field.)

Response Object 2. (if the request fails):¶

Parameter	Description
message	The error message.
error	The error name.

Here’s a curl command sample:

curl -k -X POST --data "session.id=9089beb2-576d-47e3-b040-86dbdc7f523e&name=aaaa&description=11" https://localhost:8443/manager?action=create

A sample response:

{
  "status":"success",
  "path":"manager?project=aaaa",
  "action":"redirect"
}

Delete a Project¶

The ajax API for deleting an existing project.

Notice: Currently no response message will be returned after finishing the delete operation.

Method: GET
Request URL: /manager?delete=true
Parameter Location: Request Query

Request Parameters¶

Parameter	Description
session.id	The user session id.
delete=true	The fixed parameter to indicate the deleting project action.
project	The project name to be deleted.

Here’s a curl command sample:

curl -k --get --data "session.id=bca1d75d-6bae-4163-a5b0-378a7d7b5a91&delete=true&project=test-delete-project" https://localhost:8443/manager

Upload a Project Zip¶

The ajax call to upload a project zip file. The zip file structure should follow the requirements described in Upload Projects.

Notice: This API should be called after a project is successfully created.

Method: POST
Content-Type: multipart/mixed
Request URL: /manager?ajax=upload
Parameter Location: Request Body

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=upload	The fixed parameter to the upload action.
project	The project name to be uploaded.
file	The project zip file. The type should be set as `application/zip` or `application/x-zip-compressed`.

Response Object¶

Parameter	Description
error	The error message if the upload attempt fails.
projectId	The numerical id of the project
version	The version number of the upload

Here’s a curl command sample:

curl -k -i -X POST --form 'session.id=e7a29776-5783-49d7-afa0-b0e688096b5e' --form 'ajax=upload' --form 'file=@myproject.zip;type=application/zip' --form 'project=MyProject' https://localhost:8443/manager

A response sample:

{
  "error" : "Installation Failed.\nError unzipping file.",
  "projectId" : "192",
  "version" : "1"
}

Fetch Flows of a Project¶

Given a project name, this API call fetches all flow ids of that project.

Method: GET
Request URL: /manager?ajax=fetchprojectflows
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=fetchprojectflows	The fixed parameter indicating the fetchProjectFlows action.
project	The project name to be fetched.

Response Object¶

Parameter	Description
project	The project name.
projectId	The numerical id of the project.
flows	A list of flow ids. Example values: [{“flowId”: “aaa”}, {“flowId”: “bbb”}]

Here’s a curl command sample:

curl -k --get --data "session.id=6c96e7d8-4df5-470d-88fe-259392c09eea&ajax=fetchprojectflows&project=azkaban-test-project" https://localhost:8443/manager

A response sample:

{
  "project" : "test-azkaban",
  "projectId" : 192,
  "flows" : [ {
    "flowId" : "test"
  }, {
    "flowId" : "test2"
  } ]
}

Fetch Jobs of a Flow¶

For a given project and a flow id, this API call fetches all the jobs that belong to this flow. It also returns the corresponding graph structure of those jobs.

Method: GET
Request URL: /manager?ajax=fetchflowgraph
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=fetchflowgraph	The fixed parameter indicating the fetchProjectFlows action.
project	The project name to be fetched.
flow	The project id to be fetched.

Response Object¶

Parameter	Description
project	The project name.
projectId	The numerical id of the project.
flow	The flow id fetched.
nodes	A list of job nodes belonging to this flow. Structure: { "id": "job.id" "type": "job.type" "in": ["job.ids that this job is directly depending upon. Indirect ancestors are not included in this list"] } Example values: [{“id”: “first_job”, “type”: “java”}, {“id”: “second_job”, “type”: “command”, “in”:[“first_job”]}]

Here’s a curl command sample:

curl -k --get --data "session.id=bca1d75d-6bae-4163-a5b0-378a7d7b5a91&ajax=fetchflowgraph&project=texter-1-1&flow=test" https://localhost:8445/manager

A response sample:

{
  "project" : "azkaban-test-project",
  "nodes" : [ {
    "id" : "test-final",
    "type" : "command",
    "in" : [ "test-job-3" ]
  }, {
    "id" : "test-job-start",
    "type" : "java"
  }, {
    "id" : "test-job-3",
    "type" : "java",
    "in" : [ "test-job-2" ]
  }, {
    "id" : "test-job-2",
    "type" : "java",
    "in" : [ "test-job-start" ]
  } ],
  "flow" : "test",
  "projectId" : 192
}

Fetch Executions of a Flow¶

Given a project name, and a certain flow, this API call provides a list of corresponding executions. Those executions are sorted in descendent submit time order. Also parameters are expected to specify the start index and the length of the list. This is originally used to handle pagination.

Method: GET
Request URL: /manager?ajax=fetchFlowExecutions
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=fetchFlowExecutions	The fixed parameter indicating the fetchFlowExecutions action.
project	The project name to be fetched.
flow	The flow id to be fetched.
start	The start index(inclusive) of the returned list.
length	The max length of the returned list. For example, if the start index is 2, and the length is 10, then the returned list will include executions of indices: [2, 3, 4, 5, 6, 7, 8, 9, 10, 11].

Response Object¶

Here’s a curl command sample:

curl -k --get --data "session.id=6c96e7d8-4df5-470d-88fe-259392c09eea&ajax=fetchFlowExecutions&project=azkaban-test-project&flow=test&start=0&length=3" https://localhost:8443/manager

A response sample:

{
  "executions" : [ {
    "startTime" : 1407779928865,
    "submitUser" : "1",
    "status" : "FAILED",
    "submitTime" : 1407779928829,
    "execId" : 306,
    "projectId" : 192,
    "endTime" : 1407779950602,
    "flowId" : "test"
  }, {
    "startTime" : 1407779877807,
    "submitUser" : "1",
    "status" : "FAILED",
    "submitTime" : 1407779877779,
    "execId" : 305,
    "projectId" : 192,
    "endTime" : 1407779899599,
    "flowId" : "test"
  }, {
    "startTime" : 1407779473354,
    "submitUser" : "1",
    "status" : "FAILED",
    "submitTime" : 1407779473318,
    "execId" : 304,
    "projectId" : 192,
    "endTime" : 1407779495093,
    "flowId" : "test"
  } ],
  "total" : 16,
  "project" : "azkaban-test-project",
  "length" : 3,
  "from" : 0,
  "flow" : "test",
  "projectId" : 192
}

Fetch Running Executions of a Flow¶

Given a project name and a flow id, this API call fetches only executions that are currently running.

Method: GET
Request URL: /executor?ajax=getRunning
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=getRunning	The fixed parameter indicating the getRunning action.
project	The project name to be fetched.
flow	The flow id to be fetched.

Response Object¶

Parameter	Description
execIds	A list of execution ids fetched. Example values: [301, 302, 111, 999]

Here’s a curl command sample:

curl -k --data "session.id=34ba08fd-5cfa-4b65-94c4-9117aee48dda&ajax=getRunning&project=azkaban-test-project&flow=test" https://localhost:8443/executor

A response sample:

{
  "execIds": [301, 302]
}

Execute a Flow¶

This API executes a flow via an ajax call, supporting a rich selection of different options. Running an individual job can also be achieved via this API by disabling all other jobs in the same flow.

Method: POST
Request URL: /executor?ajax=executeFlow
Parameter Location: Request Query String

Request Parameters¶

Response Object¶

Parameter	Description
error	Error message if the call has failed
flow	The executed flow id
execid	The execution id

Here is a curl command example:

curl -k -X POST --data "session.id=189b956b-f39f-421e-9a95-e3117e7543c9&ajax=executeFlow&project=azkaban-test-project&flow=test" https://localhost:8443/executor

Sample response:

{
  message: "Execution submitted successfully with exec id 295",
  project: "foo-demo",
  flow: "test",
  execid: 295
}

Cancel a Flow Execution¶

Given an execution id, this API call cancels a running flow. If the flow is not running, it will return an error message.

Method: GET
Request URL: /executor?ajax=cancelFlow
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=cancelFlow	The fixed parameter indicating the current ajax action is cancelFlow.
execid	The execution id.

Here’s a curl command sample:

curl -k --data "session.id=34ba08fd-5cfa-4b65-94c4-9117aee48dda&ajax=cancelFlow&execid=302" https://localhost:8443/executor

A response sample if succeeds:

{ }

A response sample if fails:

{
  "error" : "Execution 302 of flow test isn't running."
}

Schedule a period-based Flow (Deprecated)¶

This API call schedules a period-based flow.

Method: POST
Request URL: /schedule?ajax=scheduleFlow
Parameter Location: Request Query String

Request Parameters¶

Parameter

Description

session.id

The user session id.

ajax=scheduleFlow

The fixed parameter indicating the action is to schedule a flow.

projectName

The name of the project.

projectId

The id of the project. You can find this with Fetch Flows of a Project.

flowName

The name of the flow.

scheduleTime(with timezone)

The time to schedule the flow. Example: 12,00,pm,PDT (Unless UTC is specified, Azkaban will take current server’s default timezone instead)

scheduleDate

The date to schedule the flow. Example: 07/22/2014

is_recurring=on (optional)

Flags the schedule as a recurring schedule.

period (optional)

Specifies the recursion period. Depends on the “is_recurring” flag being set. Example: 5w Possible Values:

M	Months
w	Weeks
d	Days
h	Hours
m	Minutes
s	Seconds

Here’s a curl command sample:

# a) One time schedule
curl -k https://HOST:PORT/schedule -d "ajax=scheduleFlow&projectName=PROJECT_NAME&flow=FLOW_NAME&projectId=PROJECT_ID&scheduleTime=12,00,pm,PDT&scheduleDate=07/22/2014" -b azkaban.browser.session.id=SESSION_ID

# b) Recurring schedule
curl -k https://HOST:PORT/schedule -d "ajax=scheduleFlow&is_recurring=on&period=5w&projectName=PROJECT_NAME&flow=FLOW_NAME&projectId=PROJECT_ID&scheduleTime=12,00,pm,PDT&scheduleDate=07/22/2014" -b azkaban.browser.session.id=SESSION_ID

An example success response:

{
  "message" : "PROJECT_NAME.FLOW_NAME scheduled.",
  "status" : "success"
}

An example failure response:

{
  "message" : "Permission denied. Cannot execute FLOW_NAME",
  "status" : "error"
}

An example failure response for invalid schedule period:

{
  "message" : "PROJECT_NAME.FLOW_NAME scheduled.",
  "error" : "Invalid schedule period unit 'A",
  "status" : "success"
}

Flexible scheduling using Cron¶

This API call schedules a flow by a cron Expression. Cron is a UNIX tool that has been widely used for a long time, and we use Quartz library to parse cron Expression. All cron schedules follow the timezone defined in azkaban web server (the timezone ID is obtained by java.util.TimeZone.getDefault().getID()).

Method: POST
Request URL: /schedule?ajax=scheduleCronFlow
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=scheduleCronFlow	The fixed parameter indicating the action is to use cron to schedule a flow.
projectName	The name of the project.
flow	The name of the flow.
cronExpression	A CRON expression is a string comprising 6 or 7 fields separated by white space that represents a set of times. In azkaban, we use Quartz Cron Format.

Here’s a curl command sample:

curl -k -d ajax=scheduleCronFlow -d projectName=wtwt -d flow=azkaban-training --data-urlencode cronExpression="0 23/30 5,7-10 ? * 6#3" -b "azkaban.browser.session.id=XXXXXXXXXXXXXX" http://localhost:8081/schedule

An example success response:

{
  "message" : "PROJECT_NAME.FLOW_NAME scheduled.",
  "scheduleId" : SCHEDULE_ID,
  "status" : "success"
}

An example failure response:

{
  "message" : "Cron expression must exist.",
  "status" : "error"
}

{
  "message" : "Permission denied. Cannot execute FLOW_NAME",
  "status" : "error"
}

An example failure response for invalid cron expression:

{
  "message" : "This expression <*****> can not be parsed to quartz cron.",
  "status" : "error"
}

Fetch a Schedule¶

Given a project id and a flow id, this API call fetches the schedule.

Method: GET
Request URL: /schedule?ajax=fetchSchedule
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=fetchSchedule	The fixed parameter indicating the schedule.
projectId	The id of the project.
flowId	The name of the flow.

Here’s a curl command sample:

curl -k --get --data "session.id=XXXXXXXXXXXXXX&ajax=fetchSchedule&projectId=1&flowId=test" http://localhost:8081/schedule

An example success response:

{
  "schedule" : {
    "cronExpression" : "0 * 9 ? * *",
    "nextExecTime" : "2017-04-01 09:00:00",
    "period" : "null",
    "submitUser" : "azkaban",
    "executionOptions" : {
      "notifyOnFirstFailure" : false,
      "notifyOnLastFailure" : false,
      "failureEmails" : [ ],
      "successEmails" : [ ],
      "pipelineLevel" : null,
      "queueLevel" : 0,
      "concurrentOption" : "skip",
      "mailCreator" : "default",
      "memoryCheck" : true,
      "flowParameters" : {
      },
      "failureAction" : "FINISH_CURRENTLY_RUNNING",
      "failureEmailsOverridden" : false,
      "successEmailsOverridden" : false,
      "pipelineExecutionId" : null,
      "disabledJobs" : [ ]
    },
    "scheduleId" : "3",
    "firstSchedTime" : "2017-03-31 11:45:21"
  }
}

If there is no schedule, empty response returns.

{}

Unschedule a Flow¶

This API call unschedules a flow.

Method: POST
Request URL: /schedule?action=removeSched
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
action=removeSched	The fixed parameter indicating the action is to unschedule a flow.
scheduleId	The id of the schedule. You can find this in the Azkaban UI on the /schedule page.

Here’s a curl command sample:

curl -k https://HOST:PORT/schedule -d "action=removeSched&scheduleId=SCHEDULE_ID" -b azkaban.browser.session.id=SESSION_ID

An example success response:

{
  "message" : "flow FLOW_NAME removed from Schedules.",
  "status" : "success"
}

An example failure response:

{
  "message" : "Schedule with ID SCHEDULE_ID does not exist",
  "status" : "error"
}

Set a SLA¶

This API call sets a SLA.

Method: POST
Request URL: /schedule?ajax=setSla
Parameter Location: Request Query String

Request Parameters¶

Here’s a curl command sample:

curl -k -d "ajax=setSla&scheduleId=1&slaEmails=a@example.com;b@example.com&settings[0]=aaa,SUCCESS,5:00,true,false&settings[1]=bbb,SUCCESS,10:00,false,true" -b "azkaban.browser.session.id=XXXXXXXXXXXXXX" "http://localhost:8081/schedule"

An example success response:

{}

An example failure response:

{
  "error" : "azkaban.scheduler.ScheduleManagerException: Unable to parse duration for a SLA that needs to take actions!"
}

Fetch a SLA¶

Given a schedule id, this API call fetches the SLA.

Method: GET
Request URL: /schedule?ajax=slaInfo
Parameter Location: Request Query String

Request Parameters¶

Here’s a curl command sample:

curl -k --get --data "session.id=XXXXXXXXXXXXXX&ajax=slaInfo&scheduleId=1" http://localhost:8081/schedule"

An example success response:

{
  "settings" : [ {
    "duration" : "300m",
    "rule" : "SUCCESS",
    "id" : "aaa",
    "actions" : [ "EMAIL" ]
  }, {
    "duration" : "600m",
    "rule" : "SUCCESS",
    "id" : "bbb",
    "actions" : [ "KILL" ]
  } ],
  "slaEmails" : [ "a@example.com", "b@example.com" ],
  "allJobNames" : [ "aaa", "ccc", "bbb", "start", "end" ]
}

Pause a Flow Execution¶

Given an execution id, this API pauses a running flow. If an execution has already been paused, it will not return any error; if an execution is not running, it will return an error message.

Method: GET
Request URL: /executor?ajax=pauseFlow
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=pauseFlow	The fixed parameter indicating the current ajax action is pauseFlow.
execid	The execution id.

Here’s a curl command sample:

curl -k --data "session.id=34ba08fd-5cfa-4b65-94c4-9117aee48dda&ajax=pauseFlow&execid=303" https://localhost:8443/executor

A response sample (if succeeds, or pauseFlow is called multiple times):

{ }

A response sample (if fails, only when the flow is not actually running):

{
  "error" : "Execution 303 of flow test isn't running."
}

Resume a Flow Execution¶

Given an execution id, this API resumes a paused running flow. If an execution has already been resumed, it will not return any errors; if an execution is not running, it will return an error message.

Method: GET
Request URL: /executor?ajax=resumeFlow
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=resumeFlow	The fixed parameter indicating the current ajax action is resumeFlow.
execid	The execution id.

Here’s a curl command sample:

curl -k --data "session.id=34ba08fd-5cfa-4b65-94c4-9117aee48dda&ajax=resumeFlow&execid=303" https://localhost:8443/executor

A response sample (if succeeds, or resumeFlow is called multiple times):

{ }

A response sample (if fails, only when the flow is not actually running):

{
  "error" : "Execution 303 of flow test isn't running."
}

Fetch a Flow Execution¶

Given an execution id, this API call fetches all the detailed information of that execution, including a list of all the job executions.

Method: GET
Request URL: /executor?ajax=fetchexecflow
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=fetchexecflow	The fixed parameter indicating the fetchexecflow action.
execid	The execution id to be fetched.

Response Object¶

It returns detailed information about the execution (check the example below). One thing to notice is that the field nodes[i].in actually indicates what are the dependencies of this node.

Here’s a curl command sample:

curl -k --data "session.id=34ba08fd-5cfa-4b65-94c4-9117aee48dda&ajax=fetchexecflow&execid=304" https://localhost:8443/executor

A response sample:

{
  "attempt" : 0,
  "submitUser" : "1",
  "updateTime" : 1407779495095,
  "status" : "FAILED",
  "submitTime" : 1407779473318,
  "projectId" : 192,
  "flow" : "test",
  "endTime" : 1407779495093,
  "type" : null,
  "nestedId" : "test",
  "startTime" : 1407779473354,
  "id" : "test",
  "project" : "test-azkaban",
  "nodes" : [ {
    "attempt" : 0,
    "startTime" : 1407779495077,
    "id" : "test",
    "updateTime" : 1407779495077,
    "status" : "CANCELLED",
    "nestedId" : "test",
    "type" : "command",
    "endTime" : 1407779495077,
    "in" : [ "test-foo" ]
  }, {
    "attempt" : 0,
    "startTime" : 1407779473357,
    "id" : "test-bar",
    "updateTime" : 1407779484241,
    "status" : "SUCCEEDED",
    "nestedId" : "test-bar",
    "type" : "pig",
    "endTime" : 1407779484236
  }, {
    "attempt" : 0,
    "startTime" : 1407779484240,
    "id" : "test-foobar",
    "updateTime" : 1407779495073,
    "status" : "FAILED",
    "nestedId" : "test-foobar",
    "type" : "java",
    "endTime" : 1407779495068,
    "in" : [ "test-bar" ]
  }, {
    "attempt" : 0,
    "startTime" : 1407779495069,
    "id" : "test-foo",
    "updateTime" : 1407779495069,
    "status" : "CANCELLED",
    "nestedId" : "test-foo",
    "type" : "java",
    "endTime" : 1407779495069,
    "in" : [ "test-foobar" ]
  } ],
  "flowId" : "test",
  "execid" : 304
}

Fetch Execution Job Logs¶

Given an execution id and a job id, this API call fetches the corresponding job logs. The log text can be quite large sometimes, so this API call also expects the parameters offset and length to be specified.

Method: GET
Request URL: /executor?ajax=fetchExecJobLogs
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=fetchExecJobLogs	The fixed parameter indicating the fetchExecJobLogs action.
execid	The unique id for an execution.
jobId	The unique id for the job to be fetched.
offset	The offset for the log data.
length	The length of the log data. For example, if the offset set is 10 and the length is 1000, the returned log will starts from the 10th character and has a length of 1000 (less if the remaining log is less than 1000 long).

Response Object¶

Parameter	Description
data	The text data of the logs.
offset	The offset for the log data.
length	The length of the log data.

Here’s a curl command sample:

curl -k --data "session.id=9089beb2-576d-47e3-b040-86dbdc7f523e&ajax=fetchExecJobLogs&execid=297&jobId=test-foobar&offset=0&length=100" https://localhost:8443/executor

A response sample:

{
  "data" : "05-08-2014 16:53:02 PDT test-foobar INFO - Starting job test-foobar at 140728278",
  "length" : 100,
  "offset" : 0
}

Fetch Flow Execution Updates¶

This API call fetches the updated information for an execution. It filters by lastUpdateTime which only returns job information updated afterwards.

Method: GET
Request URL: /executor?ajax=fetchexecflowupdate
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=fetchexecflowupdate	The fixed parameter indicating the fetch execution updates action.
execid	The execution id.
lastUpdateTime	The criteria to filter by last update time. Set the value to be `-1` if all job information are needed.

Response Object¶

Parameter	Description
id	The flow id.
flow	The flow name.
startTime	The start time of this flow execution.
updateTime	The last updated time of this flow execution.
endTime	The end time of this flow execution (if it finishes).
status	The current status of the flow.
attempt	The attempt number of this flow execution.
nodes	Information for each execution job. Containing the following fields: { "attempt": String, "startTime": Number, "id": String (the job id), "updateTime":Number, "status": String, "endTime": Number }

Here’s a curl command sample:

curl -k --data "execid=301&lastUpdateTime=-1&session.id=6668c180-efe7-46a-8dd2-e36508b440d8" https://localhost:8443/executor?ajax=fetchexecflowupdate

A response sample:

{
  "id" : "test",
  "startTime" : 1407778382894,
  "attempt" : 0,
  "status" : "FAILED",
  "updateTime" : 1407778404708,
  "nodes" : [ {
    "attempt" : 0,
    "startTime" : 1407778404683,
    "id" : "test",
    "updateTime" : 1407778404683,
    "status" : "CANCELLED",
    "endTime" : 1407778404683
  }, {
    "attempt" : 0,
    "startTime" : 1407778382913,
    "id" : "test-job-1",
    "updateTime" : 1407778393850,
    "status" : "SUCCEEDED",
    "endTime" : 1407778393845
  }, {
    "attempt" : 0,
    "startTime" : 1407778393849,
    "id" : "test-job-2",
    "updateTime" : 1407778404679,
    "status" : "FAILED",
    "endTime" : 1407778404675
  }, {
    "attempt" : 0,
    "startTime" : 1407778404675,
    "id" : "test-job-3",
    "updateTime" : 1407778404675,
    "status" : "CANCELLED",
    "endTime" : 1407778404675
  } ],
  "flow" : "test",
  "endTime" : 1407778404705
}

Fetch Logs of a Project¶

Given a project name, this API call fetches all logs of a project.

Method: GET
Request URL: /manager?ajax=fetchProjectLogs
Parameter Location: Request Query String

Request Parameters¶

Parameter	Description
session.id	The user session id.
ajax=fetchProjectLogs	The fixed parameter indicating the fetchProjectLogs action.
project	The project name to be fetched.

Response Object¶

Parameter	Description
project	The project name.
projectId	The numerical id of the project.
columns	“user”, “time”, “type”, “message” columns
logData	Array of log data Example values: [ [ “test_user”, 1540885820913, “PROPERTY_OVERRIDE”, “some description” ], [ … ], [ … ], ]

Here’s a curl command sample:

curl -k --get --data "session.id=6c96e7d8-4df5-470d-88fe-259392c09eea&ajax=fetchProjectLogs&project=azkaban-test-project" https://localhost:8443/manager

A response sample:

{

“columns” : [ “user”, “time”, “type”, “message” ], “logData” : [

[ “test_user1”, 1543615522936, “PROPERTY_OVERRIDE”, “Modified Properties: …. ” ], [ “test_user2”, 1542346639933, “UPLOADED”, “Uploaded project files zip ” ], [ “test_user3”, 1519908889338, “CREATED”, null ], …

], “project” : “azkaban-test-project”, “projectId” : 1

}

Image Management APIs¶

Image Management API

How Tos¶

Force execution to an executor¶

Only users with admin privileges can use this override. In flow params: set "useExecutor" = EXECUTOR_ID.

Setting flow priority in multiple executor mode¶

Only users with admin privileges can use this property. In flow params: set "flowPriority" = PRIORITY. Higher numbers get executed first.

Enabling and Disabling Queue in multiple executor mode¶

Only users with admin privileges can use this action. Use curl or simply visit following URL:-

Enable: WEBSERVER_URL/executor?ajax=disableQueueProcessor
Disable: WEBSERVER_URL/executor?ajax=enableQueueProcessor

Reloading executors in multiple executor mode¶

Only users with admin privileges can use this action. This action need at least one active executor to be successful. Use curl or simply visit following URL:- WEBSERVER_URL/executor?ajax=reloadExecutors

Logging logs to a Kafka cluster¶

Azkaban supports sending job and flow logs to a log ingestion (such as ELK) cluster via a Kafka appender. In order to enable this in Azkaban, you will need to set three logging kafka properties (shown here with sample values):

azkaban.logging.kafka.brokers=localhost:9092
azkaban.job.logging.kafka.topic=azkaban-job-logging
azkaban.flow.logging.kafka.topic=azkaban-flow-logging

These configure where Azkaban can find your Kafka cluster, and also which topic to put the logs under. Failure to provide these parameters will result in Azkaban refusing to create a Kafka appender upon requesting one.

In order to configure jobs and flows to send its logs to Kafka, the following property needs to be set to true:

azkaban.logging.kafka.enabled=true

By default, the logging kafka log4j appender is org.apache.kafka.log4jappender.KafkaLog4jAppender: and logs will broadcast in JSON form to the Kafka cluster. It has the following

structure:

{
  "projectname": "Project name",
  "level": "INFO or ERROR",
  "submituser": "Someone",
  "projectversion": "Project version",
  "category": "Class name",
  "message": "Some log message",
  "logsource": "userJob",
  "flowid": "ID of flow",
  "execid": "ID of execution"
}

Instead of using the default kafka log4j appender, you can plug in your own logging kafka log4j appender by extending org.apache.kafka.log4jappender.KafkaLog4jAppender and set the following property to your appender:

azkaban.logging.kafka.class=a.b.c.yourKafkaLog4jAppender

You can use following properties to view the logs emitted by kafka log4j appender:

azkaban.offline.logging.enabled=true
azkaban.offline.logging.class=a.b.c.yourKafkaLogViewer

Plugins¶

Azkaban is designed to be modular. We are able to plug in code to add viewer pages or execute jobs in a customizable manner. These pages will describe the azkaban-plugins that can be downloaded from the download page and how to extend Azkaban by creating your own plugins or extending an existing one.

HadoopSecurityManager¶

The most common adoption of Azkaban has been in the big data platforms such as Hadoop, etc. Azkaban’s jobtype plugin system allows most flexible support to such systems.

Azkaban is able to support all Hadoop versions, with support for Hadoop security features; Azkaban is able to support various ecosystem components with all different versions, such as different versions of pig, hive, on the same instance.

A common pattern to achieve this is by using the HadoopSecurityManager class, which handles talking to a Hadoop cluster and take care of Hadoop security, in a secure way.

Hadoop Security with Kerberos, Hadoop Tokens¶

When Hadoop is used in enterprise production environment, it is advisable to have its security feature turned on, to protect your data and guard against mistakes.

Kerberos Authentication

The most common authentication provided by Apache Hadoop is via Kerberos, which requires a KDC to authenticate users and services.

A user can authenticate with KDC via username/password or use a keytab. KDC distributes a tgt to authenticated users. Hadoop services, such as name node and job tracker, can use this tgt to verify this is authenticated user.

Hadoop Tokens

Once a user is authenticated with Hadoop services, Hadoop will issue tokens to the user so that its internal services won’t flood KDC. For a description of tokens, see here.

Hadoop SecurityManager

For human users, one authenticate with KDC with a kinit command. But for scheduler such as Azkaban that runs jobs on behalf as other users, it needs to acquire tokens that will be used by the users. Specific Azkaban job types should handle this, with the use of HadoopSecurityManager class.

For instance, when Azkaban loads the pig job type, it will initiate a HadoopSecurityManager that is authenticated with the desired KDC and Hadoop Cluster. The pig job type conf should specify which tokens are needed to talk to different services. At minimum it needs tokens from name node and job tracker. When a pig job starts, it will go to the HadoopSecurityManager to acquire all those tokens. When the user process finishes, the pig job type calls HadoopSecurityManager again to cancel all those tokens.

Settings Common to All Hadoop Clusters¶

When a user program wants to talk to a Hadoop cluster, it needs to know where are the name node and job tracker. It also needs to know how to authenticate with them. These information are all in the Hadoop config files that are normally in $HADOOP_HOME/conf. For this reason, this conf directory as well as the hadoop-core jar need to be on azkaban executor server classpath.

If you are using Hive that uses HCat as its metastore, you also need relevant hive jars and hive conf on the classpath as well.

Native Library

Most likely your Hadoop platform depends on some native library, this should be specified in java.library.path in azkaban executor server.

temp dir

Besides those, many tools on Hadoop, such as Pig/Hive/Crunch write files into temporary directory. By default, they all go to /tmp. This could cause operations issue when a lot of jobs run concurrently. Because of this, you may want to change this by setting java.io.tmp.dir to a different directory.

Settings To Talk to UNSECURE Hadoop Cluster¶

If you are just starting out with Hadoop, chances are you don’t have kerberos authentication for your Hadoop. Depending on whether you want to run everything as azkaban user (or whatever user started the azkaban executor server), you can do the following settings:

If you started the executor server with user named azkaban, and you want to run all the jobs as azkaban on Hadoop, just set azkaban.should.proxy=false and obtain.binary.token=false
If you started the executor server with user named azkaban, but you want to run Hadoop jobs as their individual users, you need to set azkaban.should.proxy=true and obtain.binary.token=false

Settings To Talk to SECURE Hadoop Cluster¶

For secure Hadoop clusters, Azkaban needs its own kerberos keytab to authenticate with KDC. Azkaban job types should acquire necessary Hadoop tokens before user job process starts, and should cancel the tokens after user job finishes.

All job type specific settings should go to their respective plugin conf files. Some of the common settings can go to commonprivate.properties and common.properties.

For instance, Hadoop job types usually require name node tokens and job tracker tokens. These can go to commonpriate.properties.

Azkaban as proxy user

The following settings are needed for HadoopSecurityManager to authenticate with KDC:

proxy.user=YOUR_AZKABAN_KERBEROS_PRINCIPAL

This principal should also be set in core-site.xml in Hadoop conf with corresponding permissions.

proxy.keytab.location=KEYTAB_LOCATION

One should verify if the proxy user and keytab works with the specified KDC.

Obtaining tokens for user jobs

Here are what’s common for most Hadoop jobs

hadoop.security.manager.class=azkaban.security.HadoopSecurityManager_H_1_0

This implementation should work with Hadoop 1.x

azkaban.should.proxy=true
obtain.binary.token=true
obtain.namenode.token=true
obtain.jobtracker.token=true

Additionally, if your job needs to talk to HCat, for example if you have Hive installed with uses kerbrosed HCat, or your pig job needs to talk to HCat, you will need to set for those Hive job types

obtain.hcat.token=true

This makes HadoopSecurityManager acquire a HCat token as well.

Making a New Job Type on Secure Hadoop Cluster¶

If you are making a new job type that will talk to Hadoop Cluster, you can use the HadoopSecurityManager to take care of security.

For unsecure Hadoop cluster, there is nothing special that is needed.

For secure Hadoop clusters, there are two ways inlcuded in the hadoopsecuritymanager package:

give the key tab information to user job process. The hadoopsecuritymanager static method takes care of login from that common keytab and proxy to the user. This is convenient for prototyping as there will be a real tgt granted to the user job. The con side is that the user could potentially use the keytab to login and proxy as someone else, which presents a security hole.
obtain Hadoop tokens prior to user job process start. The job wrapper will pick up these binary tokens inside user job process. The tokens should be explicitly cancelled after user job finishes.

By paring properly configured hadoopsecuritymanager with basic job types such as hadoopJava, pig, hive, one can make these job types work with different versions of Hadoop with various security settings.

Included in the azkaban-plugins is the hadoopsecuritymanager for Hadoop-1.x versions. It is not compatible with Hadoop-0.20 and prior versions as Hadoop UGI is not backwards compatible. However, it should not be difficult to implement one that works with them. Going forward, Hadoop UGI is mostly backwards compatible and one only needs to recompile hadoopsecuritymanager package with newer versions of Hadoop.

Azkaban HDFS Browser¶

The Azkaban HDFS Browser is a plugin that allows you to view the HDFS FileSystem and decode several file types. It was originally created at LinkedIn to view Avro files, Linkedin’s BinaryJson format and text files. As this plugin matures further, we may add decoding of different file types in the future.

Setup¶

Download the HDFS plugin from the download page and extract it into the web server’s plugin’s directory. This is often azkaban_web_server_dir/plugins/viewer/.

Users

By default, Azkaban HDFS browser does a do-as to impersonate the logged-in user. Often times, data is created and handled by a headless account. To view these files, if user proxy is turned on, then the user can switch to the headless account as long as its validated by the UserManager.

Settings

These are properties to configure the HDFS Browser on the AzkabanWebServer. They can be set in azkaban_web_server_dir/plugins/viewer/hdfs/conf/plugin.properties.

Parameter	Description	Default
viewer.name	The name of this viewer plugin	HDFS
viewer.path	The path to this viewer plugin inside viewer directory.	hdfs
viewer.order	The order of this viewer plugin amongst all viewer plugins.	1
viewer.hidden	Whether this plugin should show up on the web UI.	false
viewer.external.class path	Extra jars this viewer plugin should load upon init.	extlib/*
viewer.servlet.class	The main servelet class for this viewer plugin. Use `azkaban.viewer.hdfs .HdfsBrowserServlet` for hdfs browser
hadoop.security.manag er.class	The class that handles talking to hadoop clusters. Use `azkaban.security.Ha doopSecurityManager_H _1_0` for hadoop 1.x
azkaban.should.proxy	Whether Azkaban should proxy as individual user hadoop accounts on a secure cluster, defaults to false	false
proxy.user	The Azkaban user configured with kerberos and hadoop. Similar to how oozie should be configured, for secure hadoop installations
proxy.keytab.location	The location of the keytab file with which Azkaban can authenticate with Kerberos for the specified proxy.user
allow.group.proxy	Whether to allow users in the same headless user group to view hdfs filesystem as that headless user	false

JobType Plugins¶

Azkaban Jobtype Plugins Configurations¶

These are properties to configure the jobtype plugins that are installed with the AzkabanExecutorServer. Note that Azkaban uses the directory structure to infer global settings versus individual jobtype specific settings. Sub-directory names also determine the job type name for running Azkaban instances.

Introduction

Jobtype plugins determine how individual jobs are actually run locally or on a remote cluster. It gives great benefits: one can add or change any job type without touching Azkaban core code; one can easily extend Azkaban to run on different hadoop versions or distributions; one can keep old versions around while adding new versions of the same types. However, it is really up to the admin who manages these plugins to make sure they are installed and configured correctly.

Upon AzkabanExecutorServer start up, Azkaban will try to load all the job type plugins it can find. Azkaban will do very simply tests and drop the bad ones. One should always try to run some test jobs to make sure the job types really work as expected.

Global Properties

One can pass global settings to all job types, including cluster dependent settings that will be used by all job types. These settings can also be specified in each job type’s own settings as well.

Private settings

One can pass global settings that are needed by job types but should not be accessible by user code in commonprivate.properties. For example, the following settings are often needed for a hadoop cluster:

Parameter	Description
hadoop.security.manager.class	The hadoopsecuritymanager that handles talking to a hadoop cluseter. Use `azkaban.security.HadoopSecurity Manager_H_1_0` for 1.x versions
azkaban.should.proxy	Whether Azkaban should proxy as individual user hadoop accounts, or run as the Azkaban user itself, defaults to `true`
proxy.user	The Azkaban user configured with kerberos and hadoop. Similar to how oozie should be configured, for secure hadoop installations
proxy.keytab.location	The location of the keytab file with which Azkaban can authenticate with Kerberos for the specified proxy.user
jobtype.global.classpath	The jars or xml resources every job type should have on their classpath. (e.g. `${hadoop.home}/hadoop-core-1.0. 4.jar,${hadoop.home}/conf`)
jobtype.global.jvm.args	The jvm args that every job type should have to jvm.
hadoop.home	The `$HADOOP_HOME` setting.

Public settings

One can pass global settings that are needed by job types and can be visible by user code, in common.properties. For example, hadoop.home should normally be passed along to user programs.

Settings for individual job types

In most cases, there is no extra settings needed for job types to work, other than variables like hadoop.home, pig.home, hive.home, etc. However, it is also where most of the customizations come from. For example, one can configure a two Java job types with the same jar resources but with different hadoop configurations, thereby submitting pig jobs to different clusters. One can also configure pig job with pre-registered jars and namespace imports for specific organizations. Also to be noted: in the list of common job type plugins, we have included different pig versions. The admin needs to make a soft link to one of them, such as

$ ln -s pig-0.10.1 pig

so that the users can use a default “pig” type.

Jobtypes¶

Azkaban job type plugin design provides great flexibility for developers to create any type of job executors which can work with essentially all types of systems – all managed and triggered by the core Azkaban work flow management.

Here we provide a common set of plugins that should be useful to most hadoop related use cases, as well as sample job packages. Most of these job types are being used in LinkedIn’s production clusters, only with different configurations. We also give a simple guide on how one can create new job types, either from scratch or by extending the old ones.

Command Job Type (built-in)¶

The command job type is one of the basic built-in types. It runs multiple UNIX commands using java processbuilder. Upon execution, Azkaban spawns off a process to run the command.

How To Use¶

One can run one or multiple commands within one command job. Here is what is needed:

Type	Command
command	The full command to run

For multiple commands, do it like command.1, command.2, etc.

Sample Job Package¶

Here is a sample job package, just to show how it works:

Download command.zip (Uploaded May 13, 2013)

HadoopShell Job Type¶

In large part, this is the same Command type. The difference is its ability to talk to a Hadoop cluster securely, via Hadoop tokens.

The HadoopShell job type is one of the basic built-in types. It runs multiple UNIX commands using java processbuilder. Upon execution, Azkaban spawns off a process to run the command.

How To Use¶

The HadoopShell job type talks to a secure cluster via Hadoop tokens. The admin should specify obtain.binary.token=true if the Hadoop cluster security is turned on. Before executing a job, Azkaban will obtain name node token and job tracker tokens for this job. These tokens will be written to a token file, to be picked up by user job process during its execution. After the job finishes, Azkaban takes care of canceling these tokens from name node and job tracker.

Since Azkaban only obtains the tokens at the beginning of the job run, and does not request new tokens or renew old tokens during the execution, it is important that the job does not run longer than configured token life.

One can run one or multiple commands within one command job. Here is what is needed:

Type	Command
command	The full command to run

For multiple commands, do it like command.1, command.2, etc.

Here are some common configurations that make a hadoopShell job for a user:

Parameter	Description
type	The type name as set by the admin, e.g. `hadoopShell`
dependencies	The other jobs in the flow this job is dependent upon.
user.to.proxy	The Hadoop user this job should run under.
hadoop-inject.FOO	FOO is automatically added to the Configuration of any Hadoop job launched.

Here are what’s needed and normally configured by the admin:

Parameter	Description
hadoop.security.manager.class	The class that handles talking to Hadoop clusters.
azkaban.should.proxy	Whether Azkaban should proxy as individual user Hadoop accounts.
proxy.user	The Azkaban user configured with kerberos and Hadoop, for secure clusters.
proxy.keytab.location	The location of the keytab file with which Azkaban can authenticate with Kerberos for the specified proxy.user
obtain.binary.token	Whether Azkaban should request tokens. Set this to true for secure clusters.

Java Job Type¶

The java job type was widely used in the original Azkaban as a built-in type. It is no longer a built-in type in Azkaban2. The javaprocess is still built-in in Azkaban2. The main difference between java and javaprocess job types are:

javaprocess runs user program that has a “main” method, java runs Azkaban provided main method which invokes user program “run” method.
Azkaban can do the setup, such as getting Kerberos ticket or requesting Hadoop tokens in the provided main in java type, whereas in javaprocess user is responsible for everything.

As a result, most users use java type for running anything that talks to Hadoop clusters. That usage should be replaced by hadoopJava type now, which is secure. But we still keep java type in the plugins for backwards compatibility.

How to Use¶

Azkaban spawns a local process for the java job type that runs user programs. It is different from the “javaprocess” job type in that Azkaban already provides a main method, called JavaJobRunnerMain. Inside JavaJobRunnerMain, it looks for the run method which can be specified by method.run (default is run). Users can also specify a cancel method in the case the user wants to gracefully terminate the job in the middle of the run.

For the most part, using java type should be no different from hadoopJava.

Sample Job¶

Please refer to the hadoopJava type.

hadoopJava Type¶

In large part, this is the same java type. The difference is its ability to talk to a Hadoop cluster securely, via Hadoop tokens. Most Hadoop job types can be created by running a hadoopJava job, such as Pig, Hive, etc.

How To Use¶

The hadoopJava type runs user java program after all. Upon execution, it tries to construct an object that has the constructor signature of constructor(String, Props) and runs its run method. If user wants to cancel the job, it tries the user defined cancel method before doing a hard kill on that process.

The hadoopJava job type talks to a secure cluster via Hadoop tokens. The admin should specify obtain.binary.token=true if the Hadoop cluster security is turned on. Before executing a job, Azkaban will obtain name node token and job tracker tokens for this job. These tokens will be written to a token file, to be picked up by user job process during its execution. After the job finishes, Azkaban takes care of canceling these tokens from name node and job tracker.

Since Azkaban only obtains the tokens at the beginning of the job run, and does not request new tokens or renew old tokens during the execution, it is important that the job does not run longer than configured token life.

If there are multiple job submissions inside the user program, the user should also take care not to have a single MR step cancel the tokens upon completion, thereby failing all other MR steps when they try to authenticate with Hadoop services.

In many cases, it is also necessary to add the following code to make sure user program picks up the Hadoop tokens in “conf” or “jobconf” like the following:

// Suppose this is how one gets the conf
Configuration conf = new Configuration();

if (System.getenv("HADOOP_TOKEN_FILE_LOCATION") != null) {
    conf.set("mapreduce.job.credentials.binary", System.getenv("HADOOP_TOKEN_FILE_LOCATION"));
}

Here are some common configurations that make a hadoopJava job for a user:

Parameter	Description
type	The type name as set by the admin, e.g. `hadoopJava`
job.class	The fully qualified name of the user job class.
classpath	The resources that should be on the execution classpath, accessible to the local filesystem.
main.args	Main arguments passed to user program.
dependencies	The other jobs in the flow this job is dependent upon.
user.to.proxy	The Hadoop user this job should run under.
method.run	The run method, defaults to run()
method.cancel	The cancel method, defaults to cancel()
getJobGeneratedProperties	The method user should implement if the output properties should be picked up and passed to the next job.
jvm.args	The `-D` for the new jvm process
hadoop-inject.FOO	FOO is automatically added to the Configuration of any Hadoop job launched.

Here are what’s needed and normally configured by the admin:

Parameter	Description
hadoop.security.manager.class	The class that handles talking to Hadoop clusters.
azkaban.should.proxy	Whether Azkaban should proxy as individual user Hadoop accounts.
proxy.user	The Azkaban user configured with kerberos and Hadoop, for secure clusters.
proxy.keytab.location	The location of the keytab file with which Azkaban can authenticate with Kerberos for the specified proxy.user
hadoop.home	The Hadoop home where the jars and conf resources are installed.
jobtype.classpath	The items that every such job should have on its classpath.
jobtype.class	Should be set to `azkaban.jobtype.HadoopJavaJob`
obtain.binary.token	Whether Azkaban should request tokens. Set this to true for secure clusters.

Since Azkaban job types are named by their directory names, the admin should also make those naming public and consistent.

Sample Job Package¶

Here is a sample job package that does a word count. It relies on a Pig job to first upload the text file onto HDFS. One can also manually upload a file and run the word count program alone. The source code is in azkaban-plugins/plugins/jobtype/src/azkaban/jobtype/examples/java/WordCount.java

Download java-wc.zip (Uploaded May 13, 2013)

Pig Type¶

Pig type is for running Pig jobs. In the azkaban-plugins repo, we have included Pig types from pig-0.9.2 to pig-0.11.0. It is up to the admin to alias one of them as the pig type for Azkaban users.

Pig type is built on using hadoop tokens to talk to secure Hadoop clusters. Therefore, individual Azkaban Pig jobs are restricted to run within the token’s lifetime, which is set by Hadoop admins. It is also important that individual MR step inside a single Pig script doesn’t cancel the tokens upon its completion. Otherwise, all following steps will fail on authentication with job tracker or name node.

Vanilla Pig types don’t provide all udf jars. It is often up to the admin who sets up Azkaban to provide a pre-configured Pig job type with company specific udfs registered and name space imported, so that the users don’t need to provide all the jars and do the configurations in their specific Pig job conf files.

How to Use¶

The Pig job runs user Pig scripts. It is important to remember, however, that running any Pig script might require a number of dependency libraries that need to be placed on local Azkaban job classpath, or be registered with Pig and carried remotely, or both. By using classpath settings, as well as pig.additional.jars and udf.import.list, the admin can create a Pig job type that has very different default behavior than the most basic “pig” type. Pig jobs talk to a secure cluster via hadoop tokens. The admin should specify obtain.binary.token=true if the hadoop cluster security is turned on. Before executing a job, Azkaban will obtain name node and job tracker tokens for this job. These tokens will be written to a token file, which will be picked up by user job process during its execution. For Hadoop 1 (HadoopSecurityManager_H_1_0), after the job finishes, Azkaban takes care of canceling these tokens from name node and job tracker. In Hadoop 2 (HadoopSecurityManager_H_2_0), due to issues with tokens being canceled prematurely, Azkaban does not cancel the tokens.

Since Azkaban only obtains the tokens at the beginning of the job run, and does not request new tokens or renew old tokens during the execution, it is important that the job does not run longer than configured token life. It is also important that individual MR step inside a single Pig script doesn’t cancel the tokens upon its completion. Otherwise, all following steps will fail on authentication with hadoop services. In Hadoop 2, you may need to set -Dmapreduce.job.complete.cancel.delegation.tokens=false to prevent tokens from being canceled prematurely.

Here are the common configurations that make a Pig job for a user:

Parameter	Description
type	The type name as set by the admin, e.g. `pig`
pig.script	The Pig script location. e.g. `src/wordcountpig.pig`
classpath	The resources that should be on the execution classpath, accessible to the local filesystem.
dependencies	The other jobs in the flow this job is dependent upon.
user.to.proxy	The hadoop user this job should run under.
pig.home	The Pig installation directory. Can be used to override the default set by Azkaban.
param.SOME_PARAM	Equivalent to Pig’s `-param`
use.user.pig.jar	If true, will use the user-provided Pig jar to launch the job. If false, the Pig jar provided by Azkaban will be used. Defaults to false.
hadoop-inject.FOO	FOO is automatically added to the Configuration of any Hadoop job launched.

Here are what’s needed and normally configured by the admin:

Parameter	Description
hadoop.security.manager.class	The class that handles talking to hadoop clusters.
azkaban.should.proxy	Whether Azkaban should proxy as individual user hadoop accounts.
proxy.user	The Azkaban user configured with kerberos and hadoop, for secure clusters.
proxy.keytab.location	The location of the keytab file with which Azkaban can authenticate with Kerberos for the specified proxy.user
hadoop.home	The hadoop home where the jars and conf resources are installed.
jobtype.classpath	The items that every such job should have on its classpath.
jobtype.class	Should be set to `azkaban.jobtype.HadoopJavaJob`
obtain.binary.token	Whether Azkaban should request tokens. Set this to true for secure clusters.

Dumping MapReduce Counters: this is useful in the case where a Pig script uses UDFs, which may add a few custom MapReduce counters

Parameter	Description
pig.dump.hadoopCounter	Setting the value of this parameter to true will trigger the dumping of MapReduce counters for each of the generated MapReduce job generated by the Pig script.

Since Pig jobs are essentially Java programs, the configurations for Java jobs could also be set.

Since Azkaban job types are named by their directory names, the admin should also make those naming public and consistent. For example, while there are multiple versions of Pig job types, the admin can link one of them as pig for default Pig type. Experimental Pig versions can be tested in parallel with a different name and can be promoted to default Pig type if it is proven stable. In LinkedIn, we also provide Pig job types that have a number of useful udf libraries, including datafu and LinkedIn specific ones, pre-registered and imported, so that users in most cases will only need Pig scripts in their Azkaban job packages.

Sample Job Package¶

Here is a sample job package that does word count. It assumes you have hadoop installed and gets some dependency jars from $HADOOP_HOME:

Download pig-wc.zip (Uploaded May 13, 2013)

Hive Type¶

The hive type is for running Hive jobs. In the azkaban-plugins repo, we have included hive type based on hive-0.8.1. It should work for higher version Hive versions as well. It is up to the admin to alias one of them as the hive type for Azkaban users.

The hive type is built using Hadoop tokens to talk to secure Hadoop clusters. Therefore, individual Azkaban Hive jobs are restricted to run within the token’s lifetime, which is set by Hadoop admin. It is also important that individual MR step inside a single Pig script doesn’t cancel the tokens upon its completion. Otherwise, all following steps will fail on authentication with the JobTracker or NameNode.

How to Use¶

The Hive job runs user Hive queries. The Hive job type talks to a secure cluster via Hadoop tokens. The admin should specify obtain.binary.token=true if the Hadoop cluster security is turned on. Before executing a job, Azkaban will obtain NameNode and JobTracker tokens for this job. These tokens will be written to a token file, which will be picked up by user job process during its execution. After the job finishes, Azkaban takes care of canceling these tokens from NameNode and JobTracker.

Since Azkaban only obtains the tokens at the beginning of the job run, and does not request new tokens or renew old tokens during the execution, it is important that the job does not run longer than configured token life. It is also important that individual MR step inside a single Pig script doesn’t cancel the tokens upon its completion. Otherwise, all following steps will fail on authentication with Hadoop services.

Here are the common configurations that make a hive job for single line Hive query:

Parameter	Description
type	The type name as set by the admin, e.g. `hive`
azk.hive.action	use `execute.query`
hive.query	Used for single line hive query.
user.to.proxy	The hadoop user this job should run under.

Specify these for a multi-line Hive query:

Parameter	Description
type	The type name as set by the admin, e.g. `hive`
azk.hive.action	use `execute.query`
hive.query.01	fill in the individual hive queries, starting from 01
user.to.proxy	The Hadoop user this job should run under.

Specify these for query from a file:

Parameter	Description
type	The type name as set by the admin, e.g. `hive`
azk.hive.action	use `execute.query`
hive.query.file	location of the query file
user.to.proxy	The Hadoop user this job should run under.

Here are what’s needed and normally configured by the admin. The following properties go into private.properties:

Parameter	Description
hadoop.security.manager.class	The class that handles talking to hadoop clusters.
azkaban.should.proxy	Whether Azkaban should proxy as individual user hadoop accounts.
proxy.user	The Azkaban user configured with kerberos and hadoop, for secure clusters.
proxy.keytab.location	The location of the keytab file with which Azkaban can authenticate with Kerberos for the specified proxy.user
hadoop.home	The hadoop home where the jars and conf resources are installed.
jobtype.classpath	The items that every such job should have on its classpath.
jobtype.class	Should be set to `azkaban.jobtype.HadoopJavaJob`
obtain.binary.token	Whether Azkaban should request tokens. Set this to true for secure clusters.
hive.aux.jars.path	Where to find auxiliary library jars
env.HADOOP_HOME	`$HADOOP_HOME`
env.HIVE_HOME	`$HIVE_HOME`
env.HIVE_AUX_JARS_PATH	`${hive.aux.jars.path}`
hive.home	`$HIVE_HOME`
hive.classpath.items	Those that need to be on hive classpath, include the conf directory

These go into plugin.properties

Parameter	Description
job.class	`azkaban.jobtype.hiveutils.azkab an.HiveViaAzkaban`
hive.aux.jars.path	Where to find auxiliary library jars
env.HIVE_HOME	`$HIVE_HOME`
env.HIVE_AUX_JARS_PATH	`${hive.aux.jars.path}`
hive.home	`$HIVE_HOME`
hive.jvm.args	`-Dhive.querylog.location=.` `-Dhive.exec.scratchdir=YOUR_HIV E_SCRATCH_DIR` `-Dhive.aux.jars.path=${hive.aux .jars.path}`

Since hive jobs are essentially java programs, the configurations for Java jobs could also be set.

Sample Job Package

Here is a sample job package. It assumes you have hadoop installed and gets some dependency jars from $HADOOP_HOME. It also assumes you have Hive installed and configured correctly, including setting up a MySQL instance for Hive Metastore.

Download hive.zip (Uploaded May 13, 2013)

New Hive Jobtype

We’ve added a new Hive jobtype whose jobtype class is azkaban.jobtype.HadoopHiveJob. The configurations have changed from the old Hive jobtype.

Here are the configurations that a user can set:

Parameter	Description
type	The type name as set by the admin, e.g. `hive`
hive.script	The relative path of your Hive script inside your Azkaban zip
user.to.proxy	The hadoop user this job should run under.
hiveconf.FOO	FOO is automatically added as a hiveconf variable. You can reference it in your script using ${hiveconf:FOO}. These variables also get added to the configuration of any launched Hadoop jobs.
hivevar.FOO	FOO is automatically added as a hivevar variable. You can reference it in your script using ${hivevar:FOO}. These variables are NOT added to the configuration of launched Hadoop jobs.
hadoop-inject.FOO	FOO is automatically added to the Configuration of any Hadoop job launched.

Here are what’s needed and normally configured by the admin. The following properties go into private.properties (or into ../commonprivate.properties):

Parameter	Description
hadoop.security.manager.class	The class that handles talking to hadoop clusters.
azkaban.should.proxy	Whether Azkaban should proxy as individual user hadoop accounts.
proxy.user	The Azkaban user configured with kerberos and hadoop, for secure clusters.
proxy.keytab.location	The location of the keytab file with which Azkaban can authenticate with Kerberos for the specified proxy.user
hadoop.home	The hadoop home where the jars and conf resources are installed.
jobtype.classpath	The items that every such job should have on its classpath.
jobtype.class	Should be set to `azkaban.jobtype.HadoopHiveJob`
obtain.binary.token	Whether Azkaban should request tokens. Set this to true for secure clusters.
obtain.hcat.token	Whether Azkaban should request HCatalog/Hive Metastore tokens. If true, the HadoopSecurityManager will acquire an HCatalog token.
hive.aux.jars.path	Where to find auxiliary library jars
hive.home	`$HIVE_HOME`

These go into plugin.properties (or into ../common.properties):

Parameter	Description
hive.aux.jars.path	Where to find auxiliary library jars
hive.home	`$HIVE_HOME`
jobtype.jvm.args	`-Dhive.querylog.location=.` `-Dhive.exec.scratchdir=YOUR_HIV E_SCRATCH_DIR` `-Dhive.aux.jars.path=${hive.aux .jars.path}`

Since hive jobs are essentially java programs, the configurations for Java jobs can also be set.

Common Configurations¶

This section lists out the configurations that are common to all job types

other_namenodes¶

This job property is useful for jobs that need to read data from or write data to more than one Hadoop NameNode. By default Azkaban requests a HDFS_DELEGATION_TOKEN on behalf of the job for the cluster that Azkaban is configured to run on. When this property is present, Azkaban will try request a HDFS_DELEGATION_TOKEN for each of the specified HDFS NameNodes.

The value of this property is in the form of comma separated list of NameNode URLs.

For example: other_namenodes=webhdfs://host1:50070,hdfs://host2:9000

HTTP Job Callback¶

The purpose of this feature to allow Azkaban to notify external systems via an HTTP upon the completion of a job. The new properties are in the following format:

job.notification.<status>.<sequence number>.url
job.notification.<status>.<sequence number>.method
job.notification.<status>.<sequence number>.body
job.notification.<status>.<sequence number>.headers

Supported values for status¶

started: when a job is started
success: when a job is completed successfully
failure: when a job failed
completed: when a job is either successfully completed or failed

Number of callback URLs¶

The maximum # of callback URLs per job is 3. So the <sequence number> can go up from 1 to 3. If a gap is detected, only the ones before the gap is used.

HTTP Method¶

The supported methods are GET and POST. The default method is GET

Headers¶

Each job callback URL can optional specify headers in the following format

job.notification.<status>.<sequence number>.headers=<name>:<value>rn<name>:<value> The delimiter for each header is ‘rn’ and delimiter between header name and value is ‘:’

The headers are applicable for both GET and POST job callback URLs.

Job Context Information¶

It is often desirable to include some dynamic context information about the job in the URL or POST request body, such as status, job name, flow name, execution id and project name. If the URL or POST request body contains any of the following tokens, they will be replaced with the actual values by Azkabn before making the HTTP callback is made. The value of each token will be HTTP encoded.

?{server} - Azkaban host name and port
?{project}
?{flow}
?{executionId}
?{job}
?{status} - possible values are started, failed, succeeded

The value of these tokens will be HTTP encoded if they are on the URL, but will not be encoded when they are in the HTTP body.

Examples¶

GET HTTP Method

job.notification.started.1.url=http://abc.com/api/v2/message?text=wow!!&job=?{job}&status=?{status}
job.notification.completed.1.url=http://abc.com/api/v2/message?text=wow!!&job=?{job}&status=?{status}
job.notification.completed.2.url=http://abc.com/api/v2/message?text=yeah!!

POST HTTP Method

job.notification.started.1.url=http://abc.com/api/v1/resource
job.notification.started.1.method=POST
job.notification.started.1.body={“type”:”workflow”, “source”:”Azkaban”, “content”:”{server}:?{project}:?{flow}:?{executionId}:?{job}:?{status}”}
job.notification.started.1.headers=Content-type:application/json

VoldemortBuildandPush Type¶

Pushing data from hadoop to voldemort store used to be entirely in java. This created lots of problems, mostly due to users having to keep track of jars and dependencies and keep them up-to-date. We created the VoldemortBuildandPush job type to address this problem. Jars and dependencies are now managed by admins; absolutely no jars or java code are required from users.

How to Use¶

This is essentially a hadoopJava job, with all jars controlled by the admins. User only need to provide a .job file for the job and specify all the parameters. The following needs to be specified:

Parameter	Description
type	The type name as set by the admin, e.g. `VoldemortBuildandPush`
push.store.name	The voldemort push store name
push.store.owners	The push store owners
push.store.description	Push store description
build.input.path	Build input path on hdfs
build.output.dir	Build output path on hdfs
build.replication.factor	replication factor number
user.to.proxy	The hadoop user this job should run under.
build.type.avro	if build and push avro data, true, otherwise, false
avro.key.field	if using Avro data, key field
avro.value.field	if using Avro data, value field

Here are what’s needed and normally configured by the admn (always put common properties in commonprivate.properties and common.properties for all job types).

These go into private.properties:

Parameter	Description
hadoop.security.manager.class	The class that handles talking to hadoop clusters.
azkaban.should.proxy	Whether Azkaban should proxy as individual user hadoop accounts.
proxy.user	The Azkaban user configured with kerberos and hadoop, for secure clusters.
proxy.keytab.location	The location of the keytab file with which Azkaban can authenticate with Kerberos for the specified `proxy.user`
hadoop.home	The hadoop home where the jars and conf resources are installed.
jobtype.classpath	The items that every such job should have on its classpath.
jobtype.class	Should be set to `azkaban.jobtype.HadoopJavaJob`
obtain.binary.token	Whether Azkaban should request tokens. Set this to true for secure clusters.
azkaban.no.user.classpath	Set to true such that Azkaban doesn’t pick up user supplied jars.

These go into plugin.properties:

Parameter	Description
job.class	`voldemort.store.readonly.mr.azk aban.VoldemortBuildAndPushJob`
voldemort.fetcher.protocol	`webhdfs`
hdfs.default.classpath.dir	HDFS location for distributed cache
hdfs.default.classpath.dir.enable	set to true if using distributed cache to ship dependency jars

For more information¶

Please refer to Voldemort project site for more info.

Create Your Own Jobtypes¶

With plugin design of Azkaban job types, it is possible to extend Azkaban for various system environments. You should be able to execute any job under the same Azkaban work flow management and scheduling.

Creating new job types is often times very easy. Here are several ways one can do it:

New Types with only Configuration Changes¶

One doesn’t always need to write java code to create job types for end users. Often times, configuration changes of existing job types would create significantly different behavior to the end users. For example, in LinkedIn, apart from the pig types, we also have pigLi types that come with all the useful library jars pre-registered and imported. This way, normal users only need to provide their pig scripts, and their own udf jars to Azkaban. The pig job should run as if it is run on the gateway machine from pig grunt. In comparison, if users are required to use the basic pig job types, they will need to package all the necessary jars in the Azkaban job package, and do all the register and import by themselves, which often poses some learning curve for new pig/Azkaban users.

The same practice applies to most other job types. Admins should create or tailor job types to their specific company needs or clusters.

New Types Using Existing Job Types¶

If one needs to create a different job type, a good starting point is to see if this can be done by using an existing job type. In hadoop land, this most often means the hadoopJava type. Essentially all hadoop jobs, from the most basic mapreduce job, to pig, hive, crunch, etc, are java programs that submit jobs to hadoop clusters. It is usually straight forward to create a job type that takes user input and runs a hadoopJava job.

For example, one can take a look at the VoldemortBuildandPush job type. It will take in user input such as which cluster to push to, voldemort store name, etc, and runs hadoopJava job that does the work. For end users though, this is a VoldemortBuildandPush job type with which they only need to fill out the .job file to push data from hadoop to voldemort stores.

The same applies to the hive type.

New Types by Extending Existing Ones¶

For the most flexibility, one can always build new types by extending the existing ones. Azkaban uses reflection to load job types that implement the job interface, and tries to construct a sample object upon loading for basic testing. When executing a real job, Azkaban calls the run method to run the job, and cancel method to cancel it.

For new hadoop job types, it is important to use the correct hadoopsecuritymanager class, which is also included in azkaban-plugins repo. This class handles talking to the hadoop cluster, and if needed, requests tokens for job execution or for name node communication.

For better security, tokens should be requested in Azkaban main process and be written to a file. Before executing user code, the job type should implement a wrapper that picks up the token file, set it in the Configuration or JobConf object. Please refer to HadoopJavaJob and HadoopPigJob to see example usage.

System Statistics¶

Azkaban server maintains certain system statistics and they can be seen http:<host>:<port>/stats

To enable this feature, add the following property “executor.metric.reports=true” to azkaban.properties

Property “executor.metric.milisecinterval.default” controls the interval at which the metrics are collected at

Statistic Types¶

Metric Name	Description
NumFailedFlowMetric	Number of failed flows
NumRunningFlowMetric	Number of flows in the queue
NumQueuedFlowMetric	Number of flows in the queue
NumRunningJobMetric	Number of running jobs
NumFailedJobMetric	Number of failed jobs

To change the statistic collection at run time, the following options are available

To change the time interval at which the specific type of statistics are collected - /stats?action=changeMetricInterval&metricName=NumRunningJobMetric&interval=60000
To change the duration at which the statistics are maintained -/stats?action=changeCleaningInterval&interval=604800000
To change the number of data points to display - /stats?action=changeEmitterPoints&numInstances=50
To enable the statistic collection - /stats?action=enableMetrics
To disable the statistic collection - /stats?action=disableMetrics

Reload Jobtypes¶

When you want to make changes to your jobtype configurations or add/remove jobtypes, you can do so without restarting the executor server. You can reload all jobtype plugins as follows:

curl http://localhost:EXEC_SERVER_PORT/executor?action=reloadJobTypePlugins

Examples¶

The project az-hadoop-jobtype-plugin provides examples that show how to use some of the included jobtypes. Below you can find how to setup a solo-server to run some of them.

java-wc¶

This example uses the pig-0.12.0 job type to upload an input file to HDFS and the hadoopJava job type to count the number of instances that each word is found.

We need to install Hadoop and Pig on the solo-server by expanding the tar into /export/apps/hadoop/latest and /export/apps/pig/latest respectively. Then set the HADOOP_HOME and PIG_HOME variables with their paths:

export HADOOP_HOME=/export/apps/hadoop/latest
export PIG_HOME=/export/apps/pig/latest

If you prefer to install Hadoop and Pig under a different path, please update common.properties and commonprivate.properties under ./az-hadoop-jobtype-plugin/src/jobtypes/ to match it.

Follow the Hadoop Single Cluster instructions to run HDFS on a single cluster. You will need to modify etc/hadoop/core-site.xml and run sbin/start-dfs.sh.

Build the source code and copy the pig-0.12.0 and hadoopJava job type directories, along with common.properties and commonprivate.properties, from ./az-hadoop-jobtype-plugin/src/jobtypes to ./azkaban-solo-server/build/install/azkaban-solo-server/plugins/jobtypes. Then start the solo server by running:

./azkaban-solo-server/build/install/azkaban-solo-server/bin/start-solo.sh

Create a zip file with the contents under ./az-hadoop-jobtype-plugin/src/examples/java-wc

Launch Azkaban by going to http://localhost:8081 and enter the credentials found under /azkaban-solo-server/conf/azkaban-users.xml.

Select Create Project, enter your project details and click Upload. Then select the zip created in the step above. Start the job by clicking on Execute Flow.

Community¶

Users and development team are in the Gitter.

Developers interested in getting more involved with Azkaban may join the mailing lists mailing lists, report bugs, and make contributions.