Configuring HBase MultiWAL
You can configure multiple write-ahead logs (MultiWAL) for HBase. If you do not configure MultiWAL, each region on a RegionServer writes to the same WAL.
A busy RegionServer might host several regions, and each write to the WAL is serial because HDFS only supports sequentially written files. This causes the WAL to negatively impact performance.
To configure MultiWAL for a RegionServer, set the value of the property
restart the RegionServer. To disable MultiWAL for a RegionServer, unset
the property and restart the RegionServer.
RegionServers using the original WAL implementation and those using the MultiWAL implementation can each handle recovery of either set of WALs, so a zero-downtime configuration update is possible through a rolling restart.