README.md

What is this?

This is an example of how one can run a scheduled rolling HBase major compaction on a table with Oozie. The compactions are performed by an hbase shell script which will major compact only one reigon per region-server at a time. Further, only regions which have a non-zero cost from a weight function will be compacted by default. Regions will be compacted in priority of those with the highest weight. For those using major compaction to increase data-locality compactions can be forced.

Steps to deploy a single-shot workflow and reocurring coordinator:

One will deploy the workflow, coordinator and files to HDFS. Then, one will submit the workflow.properties to Oozie kicking off compactions.

Configure and stage files:

1. Modify example_workflows/workflow.properties and example_workflows/coordinator.properties to match your cluster configuration (look for the items in angle brackets).
2. Modify example_workflows/coordinator.xml to match your desired frequency of compaction.
3. Upload example_workflows to HDFS (E.g. hdfs dfs -copyFromLocal example_workflows oozie_compaction`.)

NOTE: workflow.xml has a hardcoded hbase path of /usr/bin/hbase

Submit the one-time workflow and run the job:

One can follow the below steps to deploy the workflow:

1. Submit the job via oozie job -config example_workflows/workflow.properties -run.
2. One can see that their table was compacted by looking in the action's YARN logs for the string "Done Compacting".

Example output from yarn logs -applicationId application_######:

Stdoutput Regions to compact for table clay_test:
Stdoutput myhost1.example.com,60200,1556069347115 has 1 region(s) to compact
Stdoutput Compacting myhost1.example.com,60200,1556069347115 region 1d8d46167cdd550b4ac10363c0982191
Heart beat
Heart beat
Stdoutput myhost1.example.com,60200,1556069347115 region 1d8d46167cdd550b4ac10363c0982191
Stdoutput Done compacting in 68.4029998779297 seconds

Submit the scheduled coordinator to regularly run the job:

One can follow the below steps to deploy the coordinator:

1. Submit the job via oozie job -config example_workflows/coordinators.properties -run recording the coordinator ID returned.
2. Verify that only one workflow job is running via oozie job -info <coordinator ID>

Steps to run the rolling_compaction.rb script by hand

One may run the rolling_compaction.rb script manually via:

$ export table_name="<your table>"
$ export force_compaction="true|false"
$ ./rolling_compaction.rb

If one has an hbase binary not at /usr/bin/hbase, one can run:

$ export table_name="<your table>"
$ export force_compaction="true|false"
$ <path to your hbase binary> shell ./rolling_compaction.rb