8091 listener crashed (stopped listening)

hi all,

i’m running 3-node cluster, couchbase ver. 4.1.1 on 3 virtual machines (one physical server), private IPs. With very light load, just for testing. OS is Ubuntu 14.04.

Few times in week 8091 listener stops listening, happens randomly (time / cluster-node).
As I’m very new to CB I’d like to ask which error to search? What could cause the problem?

Found in babysitter.log when server wasn’t listening already.
[ns_server:info,2016-05-19T10:45:35.021+02:00,babysitter_of_ns_1@<0.301.0>:ns_port_server:log:210]moxi<0.301.0>: ERROR: could not contact REST server(s):
… which I guess is only consequence of what happened.

thanks in advance

Couchbase-Server in background has some itself protocols to itself jobs.
it seems firewall issue.did you try when firewall completely of(likeiptables -F)?
any way i suggest stop all servers, rename babysitter.log, try to view this file like tailf command and start them.
this is more complete log as i found.

thanks for reply. Anyway we don’t run firewalls on internal servers/networks. Couchbase cluster servers (3 nodes) are on same C-network.
That “stopping listening” on port 8091 happened randomly on each cluster node during a few days, week or so. Tail would help if I’d be unable to start couchbase or it crashed immediately after starting service.
As I can’t google similar problem I guess I’m missing something basic.