Couchbase Server supports upgrades from the previous major release version (Membase Server 1.7) to any minor release within Couchbase Server 1.8, or between minor releases within Couchbase Server 1.8.
Upgrades using either the online or offline method are supported only when upgrading from Membase Server 1.7 to Couchbase Server 1.8. For cluster upgrades older than Membase Server 1.7, you must upgrade to Membase Server 1.7.2 first.
For information on upgrading to Membase 1.7.x, see http://www.couchbase.com/docs/membase-manual-1.7/membase-getting-started-1-7-upgrade.html .
A known issue exists when performing a rolling upgrade from Membase Server 1.7.1 to Couchbase Server 1.8. The problem manifests itself as the rebalance process failing to complete effectively. You should perform an offline (in-place) upgrade. See Section 2.3.2, “Offline (in-place) Upgrade Process” , for more information.
The upgrade process for a cluster can be performed in two ways:
Online (rolling) Upgrades
Online upgrades enable you to upgrade your cluster without taking your cluster down, allowing your application to continue running. Using the Online upgrade method, individual nodes are removed from the cluster (using rebalancing), upgraded, and then brought back into action within the cluster.
Online upgrades natually take a long time, as each node must be taken out of the cluster, upgraded, and then brought back in. However, because the cluster can be upgraded without taking either the cluster or associated applications down, it can be a more effective method of upgrading.
For full instructions on performing an online upgrade, see Section 2.3.1, “Online (rolling) Upgrade Process” .
Starting with Couchbase Server 1.8.1, you can also make use of the swap rebalance functionality to perform an online upgrade with reduced performance impact on your cluster. For more information, see Section 184.108.40.206, “Upgrading to Couchbase Server 1.8.1 Using Swap Rebalance”.
Offline (in-place) Upgrades
Offline upgrades involve taking your application and Couchbase Server cluster offline, upgrading every node within the cluster while the cluster is down, and then restarting the upgraded cluster.
Offline upgrades can be quicker because the upgrade process can take place simultaneously on every node in the cluster. The cluster, though, must be shut down for the upgrade to take place. This disables both the cluster and all the applications that rely on it.
For full instructions on performing an offline upgrade, see Section 2.3.2, “Offline (in-place) Upgrade Process” .
|Feature||Online Upgrades||Offline Upgrades|
|Applications Remain Available||✓||✗|
|Cluster Stays in Operation||✓||✗|
|Cluster must be Shutdown||✗||✓|
|Time Required||Requires Rebalance, Upgrade, Rebalance per Node||Entire Cluster is Upgraded at Once|
Before beginning any upgrade, a backup should be taken as a best practice, see Section 5.2, “Backup and Restore with Couchbase” .
For information on backing up Membase 1.7.x, see http://www.couchbase.com/docs/membase-manual-1.7/membase-backup_1-7-0_backup.html .