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2 clusters on 1 server

snidely_whiplash
snidely_whiplash Member Posts: 576
edited Oct 23, 2017 4:23PM in Coherence Support

I'm running 2 clusters (A & B) on one server using WKA.  Everything is identical except:

coherence.cluster

coherence.localport

Is that safe?  Can the clusters ever join? 

The clusters have remained separate so far but I do see log events from the TransportService in the logs of A when I kill a storage enabled node in B.

Thanks

Answers

  • Shyam Radhakrishnan-Oracle
    Shyam Radhakrishnan-Oracle Member Posts: 80
    edited Oct 23, 2017 9:40AM

    It is safe to do so from 12.2.1 release onwards. In 12.2.1, only cluster name needs to be different, if you do not specify a local port, Coherence will use an ephemeral port, which is what we suggest from 12.2.1.

  • Mfalco-Oracle
    Mfalco-Oracle Member Posts: 503
    edited Oct 23, 2017 4:23PM

    Expanding on Shyam's description...  Prior to 12.2.1 it would be up to you to ensure the clusters didn't see one another by allocating different WKA/unicast port ranges for each cluster.  Prior to 12.2.1 each member would allocate two ports, and thus you'd need at least 2N (where N is the maximum number of cluster members) free ports between any two clusters.  In practice most people would separate them by a very wider port range.  If you didn't port separate the clusters, and they had the same name they could join with one another and depending on when the port collision occurred it could look like a split brain.   Starting with 12.2.1, you can run multiple clusters on overlapping port ranges and Coherence will utilize the unique cluster name to sort things out.  Thus with 12.2.1 you really don't need to worry about port management unless you will have a firewall between cluster members.

    thanks,

    Mark

    Oracle Coherence

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