ulimit is a command that sets limits on the user's access to system-wide resources. Specifically, it provides control over the resources available to the shell and to processes started by it.
The mapr-warden script uses the
ulimit command to set the maximum number of file descriptors (
nofile) and processes (
nproc) to 64000. Higher values are unlikely to result in an appreciable performance gain. Lower values, such as the default value of 1024, are likely to result in task failures.
MapR's recommended value is set automatically every time warden is started.
Depending on your environment, you might want to set limits manually rather than relying on Warden to set them automatically using
ulimit. The following examples show how to do this, using the recommended value of 64000.
/etc/security/limits.confand add the following line:
/etc/security/limits.d/90-nproc.confand add the following line:
- Check that the /etc/pam.d/system-auth file contains the following settings:
/etc/security/limits.confand add the following lines:
/etc/pam.d/suand uncomment the following line:
ulimit to verify settings:
- Reboot the system.
- Run the following command as the MapR user (not root) at a command line:
The command should report