How to raise max threads for elasticsearch?

Question

I have a fresh installation of Ubuntu 16.04 and I installed elasticsearch 5 on it. Now when I try to start elasticsearch using

/etc/init.d/elasticsearch start

After a few seconds in the log file I read:

[2016-11-19T08:47:31,442][ERROR][o.e.b.Bootstrap          ] [shooter-1] node validation exception
bootstrap checks failed
max number of threads [1891] for user [elasticsearch] likely too low, increase to at least [2048]

After some googling, I came to the conclusion that I had to add the following line to /etc/security/limits.conf:

elasticsearch    -       nproc           2048

However, even after this change, I still get the same error.

I found a suggestion to uncomment the line

session    required   pam_limits.so

in /etc/pam.d/su, but that line was already uncommented.

What am I missing?

score 2 · Accepted Answer · answered Nov 19 '16 at 16:13

2

Ok, I finally found it. The key was in this blogpost: https://fredrikaverpil.github.io/2016/04/27/systemd-and-resource-limits/

The solution was to edit the file /usr/lib/systemd/system/elasticsearch.service and add the line

LimitNPROC=2048

answered Nov 19 '16 at 16:13

Bart van den Burg

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hmm.. this is already set. but im still facing the error. – Srikanth Jeeva Sep 15 '17 at 19:21

score 1 · Answer 2 · answered Dec 19 '17 at 16:18

We ran into this issue also and it turned out to be a systemd service override file that we likely created when originally setting up elasticsearch.

The override file is referenced here in the docs: https://www.elastic.co/guide/en/elasticsearch/reference/current/setting-system-settings.html#systemd

Check /etc/systemd/system/elasticsearch.service.d/ for any conf files and either remove them or update them with the correct LimitNPROC= for your elasticsearch version.

amit kumar · Answer 3 · 2020-03-26T08:36:17.893

When I was checking elasticsearch service on ES nodes it was throwing below error
```
[root@h ~]# /etc/init.d/elasticsearch status
```
elasticsearch dead but subsys locked
Further checked the logs and found below errors [2020-03-26T07:41:03,281][ERROR][o.e.b.Bootstrap ] [h2-es-data-0] node validation exception [1] bootstrap checks failed [1]: max number of threads [1024] for user [elasticsearch] is too low, increase to at least [2048] [2020-03-26T07:41:03,284][INFO ][o.e.n.Node ] [h2-es-data-0] stopping ... [2020-03-26T07:41:03,322][INFO ][o.e.n.Node ] [h2-es-data-0] stopped
I have added below lines in /etc/security/limits.conf to increase threadpool on all 6 es nodes

elasticsearch - nproc 2048
Restarted services on all ES nodes
```
/etc/init.d/elasticsearch restart
```

How to raise max threads for elasticsearch?

3 Answers3