Cluster Panic due to Multicast Traffic Communication Problem

Platform Notice: Data Center Only - This article only applies to Atlassian products on the Data Center platform.

Note that this KB was created for the Data Center version of the product. Data Center KBs for non-Data-Center-specific features may also work for Server versions of the product, however they have not been tested. Support for Server* products ended on February 15th 2024. If you are running a Server product, you can visit the Atlassian Server end of support announcement to review your migration options.

*Except Fisheye and Crucible

Symptoms

There are multiple causes for this issue. Start with the parent article Confluence will not start due to fatal error in Confluence cluster.

Confluence throws the following error on a clustered deployment:

1 2 Fatal error in Confluence cluster: Database is being updated by an instance which is not part of the current cluster.  You should check network connections between cluster nodes, especially multicast traffic.

Cause

Nodes in the cluster cannot communicate. This may be due to a failed switch or other network failure.

Resolution

For Confluence 5.4 and earlier see Cluster Troubleshooting.

For Confluence Data Center 5.6 and later see Recovering from a Data Center cluster split-brain

Updated on April 8, 2025

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