Timeouts when connecting to a couchbase cluster

When connecting to a couchbase cluster some connections fail with a timeout error.

/usr/local/lib/python2.7/dist-packages/couchbase-2.1.0-py2.7-linux-x86_64.egg/couchbase/bucket.py", line 497, in get’, ’ replica=replica, no_format=no_format)’, “_TimeoutError_0x17 (generated, catch TimeoutError): <Key=u’xxxx’, RC=0x17[Client-Side timeout exceeded for operation. Inspect network conditions or increase the timeout], Operational Error, Results=1, C Source=(src/multiresult.c,309)>”]

I have check the logs and enabled the logs in the sdk and I see:

Oct 19 16:12:02 fmsdsspre08 ERROR log P25818 T140361243109120 [2] <> (SRV=0x7fa858ab86d0,IX=0) Server timed out. Some commands have failed (L:472)

Has anyone experienced this error?

I would check to ensure that the server is not under too much load, and that you are able to connect/ping all cluster nodes from the client, and finally, that the relevant ports (8091, 8092, 11210, 8093) are open.

Servers load is negligible; ports are open; what measures might we implement in the application connecting to couchbase to mitigate this problem; any recommendation?