Multiple Couchbase/Resubscriber threads when restarting couchbase

There are 2 Couchbase/Resubscriber threads running when couch-base is up & running, if the couch-base is restarted 2 more Couchbase/Resubscriber threads started running & 2 old one remains there & it seems like there can be multiple threads running simultaneously… now the problem here is that when couch base gets down next time all the running Couchbase/Resubscriber threads throws exception every 10 secs… & this results in a lot of exceptions generated in logs…

how is these threads get started & how can we avoid simultaneosly running Couchbase/Resubscriber threads–