I realise this is an old post, but I am replying to help other people with the same issue who discover this page from a search engine.
You can configure couchbase server to gather statistics less frequently by modifying the /opt/couchbase/etc/couchbase/static_config file. For details, see: https://docs.couchbase.com/server/6.5/manage/monitor/monitoring-stats-configuration.html#changing-statistics-configuration
You want to add a line to that file which looks like “{grab_stats_every_n_ticks, 60}.”. This will configure couchbase to gather stats once a minute instead of once per second. You will also need to restart the couchbase server.
I must give credit to this method which I discovered here.
Regards,
Mark