The offline upgrade process requires you to shutdown all the applications and then the entire Couchbase Server cluster. You can then perform the upgrade the software on each machine, and bring your cluster and application back up again.
If you are upgrading from Couchbase Server 1.8 to Couchbase 2.0 there are additional steps for the upgrade process because you must upgrade to Couchbase 1.8.1 for data compatibility with 2.0. For more information, see Section 2.7, “Upgrades Notes 1.8.1 to 2.0”.
It is also important that your disk write queue ( Section 10.4, “Disk Write Queue” ) has been completely drained before shutting down the cluster service. This will ensure that all data has been persisted to disk and will be available after the upgrade. It is a best practice to turn off the application and allow the queue to drain before you upgrade. It is also a best practice to perform a backup of all data before you upgrade
To upgrade an existing cluster using the offline method:
Shut down your application, so that no requests go to Couchbase Cluster. You can monitor the activity of your cluster by using Couchbase Web Console.
The cluster now needs to finish writing information to disk. This will ensure that when you restart your cluster, all of your data can be brought back into the caching layer from disk. You can do this by monitoring the Disk Write Queue in Web Console. The disk write queue should reach zero; this means no data remains to be written to disk.
On each node within the cluster, shutdown Couchbase Server on each machine. Then you can perform a standard installation upgrade to the new version of Couchbase Server. See Section 2.7.3, “Node Upgrade Process” for details.
Couchbase Server starts automatically on each node as you perform the upgrade.
As the cluster warms up, you can monitor the status of the warmup process to determine when you can switch on your application. See Section 10.3, “Monitoring startup (warmup)” .
Once the cluster finishes warmup, you can re-enable your application on the upgraded cluster.