Can one node at a time be stopped for maintenance in a k safe multi node cluster
Release : 20.2.x, 21.2.x 22.2.x
Component : PM Storage
You can stop a single node in a cluster.
As always it is *HIGHLY* advisable to have a good backup of each CA Performance Management component before stopping the nodes.
1) Backup instructions:
a) Data Repository:
See the note in those instructions:
"Important! The following procedure is the supported method for backing up the Data Repository. Taking a virtual machine snapshot is not a supported method for backing up the Data Repository"
b) Data Aggregator:
c) CA Performance Center:
2) To stop a single node:
a) Log in to any of the nodes as the dradmin and launch the adminTools UI.
b) Select Option 7 for the Advanced Menu. Select Option 2 to Stop Vertica on Host.
c) Patch the server
d) Before restarting the DR DB for the node via admintools open a Vsql session on one of the other nodes and run the following:
Run the command as the dradmin (or equivalent user) not the dauser. The password used should be the same password used to stop/start the DB via the adminTools UI.
The full commands after bringing down the DB and patching the server, but before restarting the problem node are these.
From the /opt/vertica/bin directory as the dradmin user run:
./vsql -U <dbAdminUser> -w <dbAdminPassword>
Then run this in the vsql> prompt:
Then run \q to quit the prompt.
This updates AHM, and reduces the amount of small changes that need to be sent to the down node when it restarts.
e) After the server is patched, up and operational and the make_ahm_now command is run in vsql, we can restart Vertica on the node.
Launch adminTools and from the Main Menu of adminTools select Option 5 to Restart Vertica on Host.