General notes ==================== Oozie-installer is a utility allowing building, uploading and running oozie workflows. In practice, it creates a `*.tar.gz` package that contains resouces that define a workflow and some helper scripts. This module is automatically executed when running: `mvn package -Poozie-package -Dworkflow.source.dir=classpath/to/parent/directory/of/oozie_app` on module having set: eu.dnetlib.dhp dhp-workflows in `pom.xml` file. `oozie-package` profile initializes oozie workflow packaging, `workflow.source.dir` property points to a workflow (notice: this is not a relative path but a classpath to directory usually holding `oozie_app` subdirectory). The outcome of this packaging is `oozie-package.tar.gz` file containing inside all the resources required to run Oozie workflow: - jar packages - workflow definitions - job properties - maintenance scripts Required properties ==================== In order to include proper workflow within package, `workflow.source.dir` property has to be set. It could be provided by setting `-Dworkflow.source.dir=some/job/dir` maven parameter. In oder to define full set of cluster environment properties one should create `~/.dhp/application.properties` file with the following properties: - `dhp.hadoop.frontend.user.name` - your user name on hadoop cluster and frontend machine - `dhp.hadoop.frontend.host.name` - frontend host name - `dhp.hadoop.frontend.temp.dir` - frontend directory for temporary files - `dhp.hadoop.frontend.port.ssh` - frontend machine ssh port - `oozieServiceLoc` - oozie service location required by run_workflow.sh script executing oozie job - `nameNode` - name node address - `jobTracker` - job tracker address - `oozie.execution.log.file.location` - location of file that will be created when executing oozie job, it contains output produced by `run_workflow.sh` script (needed to obtain oozie job id) - `maven.executable` - mvn command location, requires parameterization due to a different setup of CI cluster - `sparkDriverMemory` - amount of memory assigned to spark jobs driver - `sparkExecutorMemory` - amount of memory assigned to spark jobs executors - `sparkExecutorCores` - number of cores assigned to spark jobs executors All values will be overriden with the ones from `job.properties` and eventually `job-override.properties` stored in module's main folder. When overriding properties from `job.properties`, `job-override.properties` file can be created in main module directory (the one containing `pom.xml` file) and define all new properties which will override existing properties. One can provide those properties one by one as command line -D arguments. Properties overriding order is the following: 1. `pom.xml` defined properties (located in the project root dir) 2. `~/.dhp/application.properties` defined properties 3. `${workflow.source.dir}/job.properties` 4. `job-override.properties` (located in the project root dir) 5. `maven -Dparam=value` where the maven `-Dparam` property is overriding all the other ones. Workflow definition requirements ==================== `workflow.source.dir` property should point to the following directory structure: [${workflow.source.dir}] | |-job.properties (optional) | \-[oozie_app] | \-workflow.xml This property can be set using maven `-D` switch. `[oozie_app]` is the default directory name however it can be set to any value as soon as `oozieAppDir` property is provided with directory name as value. Subworkflows are supported as well and subworkflow directories should be nested within `[oozie_app]` directory. Creating oozie installer step-by-step ===================================== Automated oozie-installer steps are the following: 1. creating jar packages: `*.jar` and `*tests.jar` along with copying all dependancies in `target/dependencies` 2. reading properties from maven, `~/.dhp/application.properties`, `job.properties`, `job-override.properties` 3. invoking priming mechanism linking resources from import.txt file (currently resolving subworkflow resources) 4. assembling shell scripts for preparing Hadoop filesystem, uploading Oozie application and starting workflow 5. copying whole `${workflow.source.dir}` content to `target/${oozie.package.file.name}` 6. generating updated `job.properties` file in `target/${oozie.package.file.name}` based on maven, `~/.dhp/application.properties`, `job.properties` and `job-override.properties` 7. creating `lib` directory (or multiple directories for subworkflows for each nested directory) and copying jar packages created at step (1) to each one of them 8. bundling whole `${oozie.package.file.name}` directory into single tar.gz package Uploading oozie package and running workflow on cluster ======================================================= In order to simplify deployment and execution process two dedicated profiles were introduced: - `deploy` - `run` to be used along with `oozie-package` profile e.g. by providing `-Poozie-package,deploy,run` maven parameters. `deploy` profile supplements packaging process with: 1) uploading oozie-package via scp to `/home/${user.name}/oozie-packages` directory on `${dhp.hadoop.frontend.host.name}` machine 2) extracting uploaded package 3) uploading oozie content to hadoop cluster HDFS location defined in `oozie.wf.application.path` property (generated dynamically by maven build process, based on `${dhp.hadoop.frontend.user.name}` and `workflow.source.dir` properties) `run` profile introduces: 1) executing oozie application uploaded to HDFS cluster using `deploy` command. Triggers `run_workflow.sh` script providing runtime properties defined in `job.properties` file. Notice: ssh access to frontend machine has to be configured on system level and it is preferable to set key-based authentication in order to simplify remote operations.