HDFS-13150 for full design.
This JIRA is targeted at cleanup tasks:
- Add in integration testing. We can expand TestStandbyInProgressTail
- Documentation in HDFSHighAvailabilityWithQJM
- Remove the dummy sync added as part of
HDFS-10519; it is unnecessary since now in-progress tailing does not rely on the JN committedTxnId
A few bugs are also fixed:
- Due to changes in
HDFS-13609to enable use of the RPC mechanism whenever inProgressOK is true, there were codepaths which would use the RPC mechanism even when dfs.ha.tail-edits.in-progress was false, meaning that the JNs did not enable the cache. Update the QJM logic to only use selectRpcInputStreams if this config is true.
- Fix a false error logged when the layout version changes
- Fix the logging when a layout version change occurs to avoid printing out a placeholder value (Integer.MAX_VALUE)