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=== Replication and Failover
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The `sessions`, `authenticationSessions`, `offlineSessions` and `loginFailures` caches are the only caches that may perform replication. Entries are
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not replicated to every single node, but instead one or more nodes is chosen as an owner of that data. If a node is not the owner of a specific cache entry it queries
the cluster to obtain it. What this means for failover is that if all the nodes that own a piece of data go down, that data
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is lost forever. By default, {project_name} only specifies one owner for data. So if that one node goes down
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that data is lost. This usually means that users will be logged out and will have to login again.
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You can change the number of nodes that replicate a piece of data by change the `owners` attribute in the `distributed-cache` declaration.
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.owners
[source,xml]
----
<subsystem xmlns="urn:jboss:domain:infinispan:4.0">
<cache-container name="keycloak" jndi-name="infinispan/Keycloak">
<distributed-cache name="sessions" mode="SYNC" owners="2"/>
...
----
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Here we've changed it so at least two nodes will replicate one specific user login session.
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TIP: The number of owners recommended is really dependent on your deployment. If you do not care if users are logged
out when a node goes down, then one owner is good enough and you will avoid replication.
