Chapter 15. Rolling Upgrades In Red Hat JBoss Data Grid, rolling upgrades permit a cluster to be upgraded from one version to a new version without experiencing any downtime. This allows nodes to be upgraded without the need to restart the application or risk losing data. In JBoss Data Grid, rolling upgrades can only be performed in Remote Client-Server mode. Important When performing a rolling upgrade it is recommended to not update any cache entries in the source cluster, as this may lead to data inconsistency. Report a bug 15.1. Rolling Upgrades Using Hot Rod The following process is used to perform rolling upgrades on Red Hat JBoss Data Grid running in Remote Client-Server mode, using Hot Rod. This procedure is designed to upgrade the data grid itself, and does not upgrade the client application. Important Ensure that the correct version of the Hot Rod protocol is used with your JBoss Data Grid version: For JBoss Data Grid 6.1, use Hot Rod protocol version 1.2 For JBoss Data Grid 6.2, use Hot Rod protocol version 1.3 For JBoss Data Grid 6.3, use Hot Rod protocol version 2.0 For JBoss Data Grid 6.4, use Hot Rod protocol version 2.0 For JBoss Data Grid 6.5, use Hot Rod protocol version 2.0 For JBoss Data Grid 6.6, use Hot Rod protocol version 2.3 Prerequisite This procedure assumes that a cluster is already configured and running, and that it is using an older version of JBoss Data Grid. This cluster is referred to below as the Source Cluster and the Target Cluster refers to the new cluster to which data will be migrated. Configure the Target Cluster Use either different network settings or a different JGroups cluster name to set the Target Cluster (consisting of nodes with new JBoss Data Grid) apart from the Source Cluster. For each cache, configure a RemoteCacheStore with the following settings: Ensure that remote-server points to the Source Cluster. Ensure that the cache name matches the name of the cache on the Source Cluster. Ensure that hotrod-wrapping is enabled (set to true ). Ensure that purge is disabled (set to false ). Ensure that passivation is disabled (set to false ). Figure 15.1. Configure the Target Cluster with a RemoteCacheStore Note See the USDJDG_HOME/docs/examples/configs/ standalone-hotrod-rolling-upgrade.xml file for a full example of the Target Cluster configuration for performing Rolling Upgrades. Start the Target Cluster Start the Target Cluster's nodes. Configure each client to point to the Target Cluster instead of the Source Cluster. Eventually, the Target Cluster handles all requests instead of the Source Cluster. The Target Cluster then lazily loads data from the Source Cluster on demand using the RemoteCacheStore . Figure 15.2. Clients point to the Target Cluster with the Source Cluster as RemoteCacheStore for the Target Cluster. Dump the Source Cluster keyset When all connections are using the Target Cluster, the keyset on the Source Cluster must be dumped. This can be done using either JMX or the CLI: JMX Invoke the recordKnownGlobalKeyset operation on the RollingUpgradeManager MBean on the Source Cluster for every cache that must be migrated. CLI Invoke the upgrade --dumpkeys command on the Source Cluster for every cache that must be migrated, or use the --all switch to dump all caches in the cluster. Fetch remaining data from the Source Cluster The Target Cluster fetches all remaining data from the Source Cluster. Again, this can be done using either JMX or CLI: JMX Invoke the synchronizeData operation and specify the hotrod parameter on the RollingUpgradeManager MBean on the Target Cluster for every cache that must be migrated. CLI Invoke the upgrade --synchronize=hotrod command on the Target Cluster for every cache that must be migrated, or use the --all switch to synchronize all caches in the cluster. Disabling the RemoteCacheStore Once the Target Cluster has obtained all data from the Source Cluster, the RemoteCacheStore on the Target Cluster must be disabled. This can be done as follows: JMX Invoke the disconnectSource operation specifying the hotrod parameter on the RollingUpgradeManager MBean on the Target Cluster. CLI Invoke the upgrade --disconnectsource=hotrod command on the Target Cluster. Decommission the Source Cluster As a final step, decommission the Source Cluster. Report a bug

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