My hunch is that the problem was in the JGroups. I made sure to kill all EFM processes when they weren't cleanly killed. I didn't do anything with JGroups, however.
How can I check if JGroups are still OK?
Agreed and glad to hear that the issue solved. From the logs, it looks like the communication was not happening between the nodes that could have been resolved after the reboot.
If communication was not happening, how come "efm cluster-status efm" always gave out the correct values?
Do you mean communication JGroups-wise?
We recommend having all the servers on the same distribution of Linux.
To get a clearer picture of the possible root cause of the issue, could you please share the efm.properties files from all nodes and DB logs of the Master and Standby at the time you were performing the test.
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