DESCRIPTION:
Install or upgrade fails with Warning ulimit below 4096
DETAILS:
When either installing or upgrading a Performance Management system, the following message is observed:
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Warning: ulimit below 4096
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caadmin's max process value is lower than the recommended value of 4096, and you may see out of memory errors if you do not adjust it. Please contact your system administrator about raising the limit.
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*The number of open files has been set and verified by running: ulimit -n (returns a value of 65536)
CAUSE:
Starting with version 2.4, additional checks have been added to the install script which not only verify open file limits (ulimit -n) but also the max user processes value (ulimit -u). The max user processes value is what the check fails on, expecting the value to be at least 4096.
The following can be run on the system to verify current ulimit values: ulimit -Sa
Example output:
$ ulimit -Sa
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 385987
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 65536
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 10240
cpu time (seconds, -t) unlimited
max user processes (-u) 1024
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
SOLUTION:
There is a file in the /etc/security/limits.d directory (named like: 90-nproc.conf) that overrides the nproc setting to 1024. That file needs to be modified to comment out the values (if you plan on setting the nproc limit in the /etc/security/limits.conf), OR set them to 4096 in the 90-nproc.conf..
The easiest way is to modify the file in /etc/security/limits.d to set and change the following line
from:
* soft nproc 1024
to:
* soft nproc 4096
ADDITIONAL NOTES:
The install message about the ulimit should not prevent the install/upgrade from completing and after adjusting the nproc value accordingly (as detailed above) there will be no problem running the application.
*The documentation will be updated accordingly in a future release to include instructions on setting and verifying the max user processes value.