Of the many ways to check general server health, we're in a good position here without having to build our own system, thanks in great part to Couchbase itself. If you visit the Couchbase web admin, under your cluster, server, and bucket views, clicking on any will present some real-time statistics, as shown in the following screenshot:

These areas are also available via REST if you wish to include them in the application to make your logging and error handling more comprehensive.