Establish Limits for User Processes and File Descriptors

concept

The maximum permitted number of concurrent user processes, and currently open file descriptors, are established on Linux systems with default values that are low for running Enterprise Analytics with optimal performance and scale. The maximum number of user processes must be reset to at least 10,000 and the maximum number of file descriptors to at least 200,000.

To establish limits for user processes and file descriptors:

To check the current setting for user processes for the current administrator, use:
```
ulimit -u
```
The response indicates the maximum number of user processes permitted for the administrator, which this example assumes to be the default value, applied to all users.
```
3829
```
In this case, the number 3829`is lesser than the Enterprise-Analytics requirement of `10000.
To check the current setting for file descriptors, use:
```
ulimit -n
```
The response indicates the maximum number of file descriptors permitted for the administrator, which this example assumes to be the default value, applied to all users.
```
1024
```
In this case, the number 1024 is lesser than the Enterprise-Analytics requirement of 200000.
To raise the current limits on user processes and file descriptors, access /etc/security/limits.conf, and add hard and soft lines for the nproc and nofile types, specifying appropriate values. The domain value should be the user-name of the user, or the group-name of the group, designated to install and run Enterprise Analytics.

Following these additions, the lines should appear as follows:
```
nameofuserorgroup       soft    nproc           10000
nameofuserorgroup       hard    nproc           10000

nameofuserorgroup       soft    nofile          200000
nameofuserorgroup       hard    nofile          200000
```
Save the file and exit.
Reboot the machine.

Following reboot, the designated user or group-member can check all the limits that apply to them, as follows:

ulimit -a

This displays a list of limits for the designated user or group, among which appear the modified values for user processes and file descriptors:

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 3829
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 200000
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 10000
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited