Why does SPLUNK recommend setting the ulimit settings for core file size to unlimited?

[M2016G0216]

The ulimit -c (for core file size) currently reads:

core file size (blocks, -c) 0

[harish_l]

splunk recommended ulimit is 64000 but what is maximum ulimit ?

[ddrillic · Accepted solution]

A lovely explanation especially for the indexers at What's Your ulimit

It says -

-- Therefore, a super safe ulimit will be 8 x # forwarders to account for the additional file descriptors Splunk will need for reading/writing during indexing/searching. This setting is very important for indexers as we are expecting constant concurrent connections from forwarders.

Now if you have a 1000 forwarders, like us, we can see why the ulimit should be high...

It also says -
-- It doesn’t hurt to remove the hard limit and set ulimit to unlimited… unless there is some kind of file descriptor leak in Splunk. Such a leak can go undetected for a long time and consume more and more resources. We don’t expect this to happen since we do monitor specifically for these types of problems in our longevity tests conducted with 1000 forwarders across 10 indexers over many days with ulimit set at 2048.