Validating the Upgrade Manually
Although the upgrade process includes some basic service checks, those checks are cursory. You must test the critical components that you identified during your upgrade planning and thereby validate the entire cluster.
Table 5.1. Validating the Upgrade Manually by Component
Your preupgrade planning process should identify a list of critical applications, streaming applications, Hive jobs, and HBase client access points. Have a test plan put together ensures your components are working properly after the upgrade. This is especially important for applications that need to be re-compiled.
You should have ready a series of tests that test:
MapReduce
Consider running Teragen or Sort on a substantial dataset. Use these to baseline the new configuration for future reference.
HBase
Hive with both engines: MR and Tez
Storm
Kafka
Other cluster-utilitzed components