To prepare a node for an HBase upgrade:
Pause the Hbase load balancer via the HBase shell. For example:
- Identify the node in your cluster that serves the lowest number of HBase regions.
Stop all HBase services on that node. See the HBase documentation for details about the
graceful_stop.shscript, which you can use to gracefully stop regions after pausing the load balancer. This script gradually unloads regions, allowing the node to be shut down without affecting data availability:
Alternatively, you can use the MCS or a maprcli command to shut down the RegionServer on that node without first unloading regions. However, this option results in a short window of data unavailability while HBase data-recovery operations are running.
- Continue with the main HBase upgrade procedure, starting with an installation of
mapr-hbaseon that node.
If your upgrade plan includes both a new version of the MapR distribution and a new version of HBase, follow these steps before upgrading the MapR software.