Common admin tasks

For general running and configuration, Couchbase Server is self-managing. The management infrastructure and components of the Couchbase Server system are able to adapt to the different events within the cluster. There are only a few different configuration variables. The majority of these configuration variables do not need to be modified or altered in most installations.

However, there are a number of different tasks that are performed over the lifetime of the cluster environment including:

  • Expand your cluster when you need to expand the RAM or disk I/O capabilities.
  • Failover and altering the size of your cluster as your application demands change.
  • Monitoring and reacting to the various statistics reported by the server to ensure that your cluster is operating at the highest performance level.
  • Backing up the cluster.

Increasing or reducing your cluster size

When your cluster requires additional RAM, disk I/O or network capacity, you will need to expand the size of your cluster. If the increased load is only a temporary event, then you may later want to reduce the size of your cluster.

You can add or remove multiple nodes from your cluster at the same time. Once the new node arrangement has been configured, the process redistributing the data and bringing the nodes into the cluster is called rebalancing. The rebalancing process moves the data around the cluster to match the new structure, and can be performed live while the cluster is still servicing application data requests.

Warming up a server

There may be cases where you want to explicitly shutdown a server and then restart it. Typically the server had been running for a while and has data stored on disk when you restart it. In this case, the server needs to undergo a warmup process before it can again serve data requests.

Handling a failover situation

A failover situation occurs when one of the nodes within your cluster fails, usually due to a significant hardware or network problem. Couchbase Server is designed to cope with this situation through the use of replicas which provide copies of the data around the cluster which can be activated when a node fails.

Couchbase Server provides two mechanisms for handling failover. Automated Failover enables the cluster to operate autonomously and react to failovers without human intervention. Monitored failover enables you to perform a controlled failure by manually failing over a node. There are additional considerations for each failover type, and you should read the notes to ensure that you know the best solution for your specific situation.

Managing database and view fragmentation

The database and view index files created by Couchbase Server can become fragmented. This can cause performance problems, as well as increasing the space used on disk by the files, compared to the size of the information they hold. Compaction reduces this fragmentation to reclaim the disk space.

Backing up and restoring your cluster data

Couchbase Server automatically distributes your data across the nodes within the cluster, and supports replicas of that data. It is good practice, however, to have a backup of your bucket data in the event of a more significant failure.