[ClusterLabs] Antw: [EXT] Pacemaker alerts log duplication.

[Ulrich Windl]

>>> Amol Shinde <amol.shinde at seagate.com> schrieb am 08.07.2021 um 08:58 in
Nachricht
<MW3PR20MB3385122EBAC1AB9282C3F91AE9199 at MW3PR20MB3385.namprd20.prod.outlook.com>

> Hello everyone!!!
> Hope you are doing well.
> I need some help regarding pacemaker alerts. I have a 36‑node cluster setup

> with some IP and dummy resources. I have also deployed an alert script for 
> the cluster that monitors the node and resources and generates alerts on 
> events occurrence. The alert script is present on all nodes and sends the 
> captured alert to a Web‑UI using a message bus. So, for example, when a node

> goes offline pacemaker triggers the alert agent script on other nodes in the

> cluster and logs the event as "Node is lost". This message is then sent to 
> the message bus by the script.
> 
> The problem is that since the alert is triggered on every node the agent 
> script sends multiple duplicate log messages to the message bus. Multiple 
> duplicate log messages from all the live nodes are reported to the Web‑UI
thus 
> clogging up the interface and making parsing through it difficult and
ruining 
> the user experience.
> 
> Is there any way in the pacemaker itself through which when an event occurs

> the pacemaker calls the agent on any one node and logs the message rather 
> than calling the agent on all live nodes within the cluster? For example, 
> when a node goes offline, the agent is triggered on any one of the live
nodes 
> on the cluster thus generating one log, rather than generating multiple 
> duplicate logs for the same event.

If there were (actually I don't know) a cluster-wide "event-ID" (e.g. sequence
number) and that event ID would be passed to the alerting function, then you'd
still create multiple events, but the backend could suppress multiple events
about the same event ID.

Regards,
Ulrich