Neo4j WARNING: Max 1024 open files allowed, minimum of 40 000 recommended. See the Neo4j manual

Question

I installed Neo4j on Ubuntu 12.04 using these instructions: http://www.neo4j.org/download/linux

wget -O - http://debian.neo4j.org/neotechnology.gpg.key | apt         


        

Answer 1

The solutions posted by @israel and by @Tomasz Swider did not work for me (I am running Ubuntu 14.04). However, I could get rid of this warning by modifying the file /etc/init.d/neo4j-service as suggested by @zwol in the comments below the question:

I added the line ulimit -n 40000 to the do_start() method in this file. In my case this method then looks as follows:

do_start()
{
        # Return
        #   0 if daemon has been started
        #   1 if daemon was already running
        #   2 if daemon could not be started
        ulimit -n 40000
        start-stop-daemon --chuid ${NEO_USER} --start --quiet --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
                || return 1
        start-stop-daemon --chuid ${NEO_USER} --start --quiet --pidfile $PIDFILE --exec $DAEMON -- \
                $DAEMON_ARGS \
                || return 2
}

When I then start the service by using the command

sudo service neo4j-service start

it starts without the warning and returns the following message:

Starting Neo4j Server...WARNING: not changing user
process [9921]... waiting for server to be ready...... OK.
http://localhost:7474/ is ready.

I am not sure whether that is the way to go but as written above, that was the only solution that has worked for me so far to get rid of this warning.

EDIT:

Have not tested it, but seems there is now an easier solution available: see @Schrodinger's'Cat's answer.