Increase CentOS 6 Thread/Process Limit
In Linux OS, CentOS 6.x, there is limit to the number of created threads / processes.
The default setting is 1024.
In CentOS 5.x, it can be more than 40000 or no limit.
To increase threads on CentOS 6.x
1. Open and edit /etc/security/limits.d/90-nproc.conf
2. Increase the number in the following line or comment out the line:
* soft nproc 1024
3. Restart machine