Problems Starting Couchbase Server for the first time

If you are having problems starting Couchbase Server on Linux for the first time, there are two very common causes of this that are actually quite related. When the /etc/init.d/couchbase-server script runs, it tries to set the file descriptor limit and core file size limit:

shell> ulimit -n 10240 ulimit -c unlimited

Depending on the defaults of your system, this may or may not be allowed. If Couchbase Server is failing to start, you can look through the logs and pick out one or both of these messages:

ns_log: logging ns_port_server:0:Port server memcached on node 'ns_1@127.0.0.1' exited with status 71. »
Restarting. Messages: failed to set rlimit for open files. »
Try running as root or requesting smaller maxconns value.

Alternatively you may additional see or optionally see:

ns_port_server:0:info:message - Port server memcached on node 'ns_1@127.0.0.1' exited with status 71. »
Restarting. Messages: failed to ensure corefile creation

The resolution to these is to edit the /etc/security/limits.conf file and add these entries:

couchbase hard nofile 10240
couchbase hard core unlimited