neo4j and max open files

Question

I'm using neo4j 1.8M06 on ubuntu. When I start it, I get this warning:

WARNING: Max 1024 open files allowed, minimum of 40 000 recommended.

what does it mean? If it is required, how can I adjust this setting?

I've seen this thread on the issue but still could not understand it.

Answer 1

It means that you can open only '1024'(default) files for writing. But NEO4J recommends this value to be 40K. This can be achieved with the fix as described below.

Edit /etc/security/limits.conf and add these two lines:

root   soft    nofile  40000
root   hard    nofile  40000

The neo4j recommends "neo4j" in place of "root" here. That won't work.

You also need to edit /etc/pam.d/common-session* and add the following line to the end:

session required pam_limits.so

And yes, finally you've to restart NEO4J.

sudo service neo4j-service restart

Reference: NEO4J server setup

Answer 2

For now(neo4j 3.1.1), neo4j has the official solution for this.

Most Neo4j configuration goes into neo4j.conf. Some package-specific options are set in /etc/default/neo4j.

Add this config to /etc/default/neo4j

NEO4J_ULIMIT_NOFILE=40000

then restart the neo4j service to get it work.

sudo service neo4j start

see

• https://neo4j.com/docs/operations-manual/current/installation/linux/debian/#debian-operation
• https://neo4j.com/developer/kb/how-do-i-set-max-open-files-for-debian-installs/