Hi Roger,

What we know about starting the offline agent (i.e. in offline mode), is to give it time to synchronize (this could take a while).

If you start the offline agent and directly make it online, it will first synchronize and only then start up its UI (likely causing hours of delay).

Let's see if the experts might have something to add on the subject.

Hi,

It depends a bit on what you mean by self-hosted Cassandra/OpenSearch.

If you're using dedicated clustered storage (shared Cassandra and OpenSearch clusters), then the database synchronization is handled by Cassandra/OpenSearch themselves, not by the DataMiner failover synchronization.

In that case, I'd expect the backup agent to reconnect normally after being brought back online. Once it's up:

• Wait for a midnight sync to occur.
• Check the Failover status in DataMiner Cube.
• Review the logs for any SLErrors related to Failover or synchronization.
• Verify there are no Cassandra/OpenSearch connectivity or health issues.

Regarding your second question, it depends on the database architecture:

If you have a single Cassandra cluster (single DC), both the active and backup agent will connect directly to that cluster.
If you have a multi-DC Cassandra deployment, each agent will typically connect to its preferred DC, while the Cassandra clusters handle replication/synchronization between the DCs themselves.

So, in short: if you're using shared clustered storage, the databases should take care of catching up themselves. After bringing the backup agent online, I'd mainly validate that the midnight sync completes successfully, the Failover status is healthy, and there are no sync-related errors in the logs