Connection Timeouts

Hi guys,
I’m trying to use a couchbase cluster with nodejs, with a big load. (Couchbase 2.2.0 nodejs SDK 2.0.0-dp1)

After some hours each connection to couchbase seems to slow down by itself, ending up with connection timouts.

Our temporary solution is to restart each connection every 10 min in order avoid this problem.
Is it normal? Any other solution proposed? Is there a maximum of open connection to a couchbase server?

Thanks in advance for your help!!!