Database Reference
In-Depth Information
The following are the recommended steps to perform the rolling upgrades:
1. Install the new HBase version on all the nodes (do not conigure).
2.
Disable the balancer process.
3.
Decommission the region server gracefully (refer to the previous section).
Once done, perform the coniguration (setting the class path) if any, with the
new version and bring back the server.
4.
Repeat the preceding steps for all the region servers.
5.
Restart master servers.
6.
Enable the balancer process.
7.
Run the
$./bin/hbase hbck
command to ensure that the cluster is consistent.
8.
Upgrade the client with HBase binaries if required.
By performing these steps, there is much less possibility of facing any issue with the
upgrading process.
HBase cluster consistency
HBase comes with a utility called
hbck
to check the region consistency. This utility
also runs periodically to keep track of the integrity of the HBase tables. In newer
versions of HBase, such as 0.92.2+ and 0.94.0+, this utility is referred to as
uberhbck
.
You can run the
hbck
tool to detect inconsistencies, as shown in the following
command:
$HBASE_HOME/bin/hbase hbck
On executing the command, the following summary about the cluster is displayed :
