Slider AppPackages are a declarative definition of an application for application management. AppPackage is not a packaging scheme for application binaries and artifacts. Tarball, zip files, rpms etc. are available for that purpose. Instead AppPackage includes the application binaries along with other artifacts necessary for application management.
An application instance consists of several active component such as one or more masters and several slaves. There may be a number of accompanying processes in addition to the basic master/slave processes - lets refer to all processes as app component instances. When run in the context of Yarn, the application specific processes are activated within individual Yarn Container. If you pry into an Yarn container (created through Slider) it will be apparent as to what is the role of Slider-Agent and the actual application components. The following image provides an high-level view. Within a container there are at least two processes - and instance of a slider agent and an instance of an application component. The application can itself spawn more procsses if needed.
Figure 1 - High-level view of a container
yarn 8849 -- python ./infra/agent/slider-agent/agent/main.py --label container_1397675825552_0011_01_000003___HBASE_REGIONSERVER --host AM_HOST --port 47830 yarn 9085 -- bash /hadoop/yarn/local/usercache/yarn/appcache/application_1397675825552_0011/ ... internal_start regionserver yarn 9114 -- /usr/jdk64/jdk1.7.0_45/bin/java -Dproc_regionserver -XX:OnOutOfMemoryError=...
The above list shows three processes, the Slider-Agent process, the bash script to start HBase Region Server and the HBase Region server itself. Three of these together constitute the container.
The following command creates an HBase application using the AppPackage for HBase.
./slider create cl1 --image hdfs://NN:8020/slider/agent/slider-agent.tar.gz --template /work/appConf.json --resources /work/resources.json
Lets analyze various parameters from the perspective of app creation:
--image: its the slider agent tarball
--template: app configuration
--resources: yarn resource requests
The structure of an AppPackage is described at AppPackage.
In the enlistment, there are three example AppPackages:
The above folders, with minor edits, can be packaged as zip files to get the corresponding AppPackages. The application tarball file, containing the binaries/artifacts of the application itself is a component within the AppPackage. They are:
They are placehoder files, mostly because the files themselves are too large as well as users are free to use their own version of the package. To create a Slider AppPackage - replace the file with an actual application tarball and then ensure that the metainfo.xml has the correct file name. After that create a zip file using standard zip commands and ensure that the package has the metainfo.xml file at the root folder.
Archive: hbase_v096.zip Length Date Time Name -------- ---- ---- ---- 3163 05-16-14 16:32 appConfig.json 0 05-02-14 07:51 configuration/ 5077 05-02-14 07:51 configuration/global.xml 5248 05-02-14 07:51 configuration/hbase-log4j.xml 2250 05-02-14 07:51 configuration/hbase-policy.xml 14705 05-02-14 07:51 configuration/hbase-site.xml 3332 05-16-14 16:33 metainfo.xml 0 05-02-14 07:51 package/ 0 05-19-14 20:36 package/files/ 83154798 05-19-14 20:36 package/files/hbase-0.96.1-hadoop2-bin.tar.gz 0 05-02-14 07:51 package/scripts/ 787 05-02-14 07:51 package/scripts/__init__.py 1378 05-02-14 07:51 package/scripts/functions.py 3599 05-02-14 07:51 package/scripts/hbase.py 1205 05-02-14 07:51 package/scripts/hbase_client.py 1640 05-02-14 07:51 package/scripts/hbase_master.py 1764 05-02-14 07:51 package/scripts/hbase_regionserver.py 1482 05-02-14 07:51 package/scripts/hbase_service.py 4924 05-02-14 07:51 package/scripts/params.py 973 05-02-14 07:51 package/scripts/status_params.py 0 05-02-14 07:51 package/templates/ 2723 05-02-14 07:51 package/templates/hadoop-metrics2-hbase.properties-GANGLIA-MASTER.j2 2723 05-02-14 07:51 package/templates/hadoop-metrics2-hbase.properties-GANGLIA-RS.j2 3878 05-02-14 07:51 package/templates/hbase-env.sh.j2 909 05-02-14 07:51 package/templates/hbase_client_jaas.conf.j2 989 05-02-14 07:51 package/templates/hbase_master_jaas.conf.j2 1001 05-02-14 07:51 package/templates/hbase_regionserver_jaas.conf.j2 837 05-02-14 07:51 package/templates/regionservers.j2 357 05-12-14 12:04 resources.json -------- ------- 83219742 29 files
Sample resources.json and appConfig.json files are also included in the enlistment. These are samples and are typically tested on one node test installations.
An appConfig.json contains the application configuration. See Specifications InstanceConfiguration for details on how to create a template config file. The enlistment includes sample config files for HBase, Accumulo, and Storm.
Resource specification is an input to Slider to specify the Yarn resource needs for each component type that belong to the application. Specification of Resources describes how to write a resource config json file. The enlistment includes sample config files for HBase, Accumulo, and Storm.
Refer to App Command Scripts for details on how to write scripts for a AppPackage. These scripts are in the package/script folder within the AppPackage. Use the checked in samples for HBase/Storm/Accumulo as reference for script development.