How to increase Neo4j's maximum file open limit (ulimit) in Ubuntu?

Solution 1:

What you are doing will not work for root user. Maybe you are running your services as root and hence you don't get to see the change.

To increase the ulimit for root user you should replace the * by root. * does not apply for root user. Rest is the same as you did. I will re-quote it here.

Add the following lines to the file: /etc/security/limits.conf

root soft  nofile 40000

root hard  nofile 40000

And then add following line in the file: /etc/pam.d/common-session

session required pam_limits.so

This will update the ulimit for root user. As mentioned in comments, you may don't even have to reboot to see the change.

Solution 2:

1) Check sysctl file-max limit:

$ cat /proc/sys/fs/file-max

If the limit is lower than your desired value, open the sysctl.conf and add this line at the end of file:

fs.file-max = 65536

Finally, apply sysctl limits:

$ sysctl -p 

2) Edit /etc/security/limits.conf and add below the mentioned

* soft     nproc          65535    
* hard     nproc          65535   
* soft     nofile         65535   
* hard     nofile         65535

These limits won't apply for root user, if you want to change root limits you have to do that explicitly:

root soft     nofile         65535   
root hard     nofile         65535
...

3) Reboot system or add following line to the end of /etc/pam.d/common-session:

session required pam_limits.so

Logout and login again.

4) Check soft limits:

$ ulimit -a

and hard limits:

$ ulimit -Ha
....

open files                      (-n) 65535

Reference : http://ithubinfo.blogspot.in/2013/07/how-to-increase-ulimit-open-file-and.html

Solution 3:

I am using Debian but this solution should work fine with Ubuntu.
You have to add a line in the neo4j-service script.
Here is what I have done :

nano /etc/init.d/neo4j-service
Add « ulimit –n 40000 » just before the start-stop-daemon line in the do_start section

Note that I am using version 2.0 Enterprise edition. Hope this will help you.

Solution 4:

I was having the same issue, and got it to work by adding entries to /etc/security/limits.d/90-somefile.conf. Note that in order to see the limits working, I had to log out completely from the ssh session, and then log back in.

I wanted to set the limit for a specific user that runs a service, but it seems that I was getting the limit that was set for the user I was logging in as. Here's an example to show how the ulimit is set based on authenticated user, and not the effective user:

$ sudo cat /etc/security/limits.d/90-nofiles.conf
loginuser    soft    nofile   10240
loginuser    hard    nofile   10240
root         soft    nofile   10241
root         hard    nofile   10241
serviceuser  soft    nofile   10242
serviceuser  hard    nofile   10242

$ whoami
loginuser
$ ulimit -n
10240
$ sudo -i
# ulimit -n
10240    # loginuser's limit
# su - serviceuser
$ ulimit -n
10240    # still loginuser's limit.

You can use an * to specify an increase for all users. If I restart the service as the user I logged in, and add ulimit -n to the init script, I see that the initial login user's limits are in place. I have not had a chance to verify which user's limits are used during a system boot or of determining what the actual nofile limit is of the service I am running (which is started with start-stop-daemon).

There's 2 approaches that are working for now:

1. add a ulimit adjustment to the init script, just before start-stop-daemon.
2. wildcard or more extensive ulimit settings in the security file.