"Too many open files" when executing gatling on Mac

Question

When executing gatling (load test tools) from shell on Mac iOS (El Capitan) on my Macbook Pro 15 ' (16 Giga of RAM, 4 physical cores), i've the error "Too many open files".

I spend days to fix this problem, without any success :

• I created a file in /Library/LaunchDaemons/limit.maxfiles.plist with a XML file content copied from the web, no result.

• sudo ulimit -n 15000 doesn't work.

• I created a file /etc/sysctl.conf with the following content

kern.maxfiles=20480
kern.maxfilesperproc=20480

• I tried the command "sudo launchctl limit maxfiles 20480 20480" without any result.

I think that the xml file in "/Library/LaunchDaemons/" seem have some effect, because when i change the value of the maxfiles, the command "sudo launchctl limit" display to me the value i entered in the XML file, and when calling "ulimit -n" with some value, it accept every values less than this value, but when i call "ulimit -n", the result is everytime the same "4096".

I saw that in Java, the limit is 10240, so i tried the VM option (-XX:-MaxFDLimit) without any effect.

On strange thing, when i executed Gatling from Intellij (IDE), i ca go until 10 200 sockets. The same thing, give differents effects, even after executing all commands in all combinaisons (ulimit, sysctl, launchctl, ...).

Best regards

Answer 1

Just in case any one else lands here from google, here are the steps required to change the open files limit on the latest versions of OS X:

1. In /Library/LaunchDaemons create a file named limit.maxfiles.plist and paste the following in (feel free to change the two numbers (which are the soft and hard limits, respectively):

<?xml version="1.0" encoding="UTF-8"?>  
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"  
        "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">  
  <dict>
    <key>Label</key>
    <string>limit.maxfiles</string>
    <key>ProgramArguments</key>
    <array>
      <string>launchctl</string>
      <string>limit</string>
      <string>maxfiles</string>
      <string>64000</string>
      <string>524288</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
    <key>ServiceIPC</key>
    <false/>
  </dict>
</plist> 

2. Change the owner of your new file:

sudo chown root:wheel /Library/LaunchDaemons/limit.maxfiles.plist

3. Check current settings launchctl limit maxfiles

4. Load these new settings:

sudo launchctl load -w /Library/LaunchDaemons/limit.maxfiles.plist

5. Finally, check that the limits are correct:

launchctl limit maxfiles