Increasing values for max_user_watches and max_map_count

[abeer91]

Description of changes:

Increasing values for max_user_watches and max_map_count , which we've heard have had low values by default from a few customers.

#501

Before making these changes:

[ec2-user@ip-192-168-95-3 ~]$ sudo docker run -it --rm ubuntu bash -c "cat /proc/sys/fs/inotify/max_user_watches"
Unable to find image 'ubuntu:latest' locally
latest: Pulling from library/ubuntu
da7391352a9b: Pull complete
14428a6d4bcd: Pull complete
2c2d948710f2: Pull complete
Digest: sha256:c95a8e48bf88e9849f3e0f723d9f49fa12c5a00cfc6e60d2bc99d87555295e4c
Status: Downloaded newer image for ubuntu:latest
8192

[ec2-user@ip-192-168-95-3 ~]$ cat /proc/sys/vm/max_map_count
65530

Starting elastic search fails due to low max_map_count

ERROR: [1] bootstrap checks failed
[1]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
ERROR: Elasticsearch did not exit normally - check the logs at /usr/share/elasticsearch/logs/quickstart.log
{"type": "server", "timestamp": "2020-12-18T08:18:33,724Z", "level": "INFO", "component": "o.e.n.Node", "cluster.name": "quickstart", "node.name": "quickstart-es-default-0", "message": "stopping ..." }
{"type": "server", "timestamp": "2020-12-18T08:18:33,737Z", "level": "INFO", "component": "o.e.n.Node", "cluster.name": "quickstart", "node.name": "quickstart-es-default-0", "message": "stopped" }
{"type": "server", "timestamp": "2020-12-18T08:18:33,738Z", "level": "INFO", "component": "o.e.n.Node", "cluster.name": "quickstart", "node.name": "quickstart-es-default-0", "message": "closing ..." }
{"type": "server", "timestamp": "2020-12-18T08:18:33,753Z", "level": "INFO", "component": "o.e.n.Node", "cluster.name": "quickstart", "node.name": "quickstart-es-default-0", "message": "closed" }
{"type": "server", "timestamp": "2020-12-18T08:18:33,755Z", "level": "INFO", "component": "o.e.x.m.p.NativeController", "cluster.name": "quickstart", "node.name": "quickstart-es-default-0", "message": "Native controller process has stopped - no new native processes can be started" }

> kubectl get elasticsearch

NAME         HEALTH    NODES   VERSION   PHASE             AGE
quickstart   unknown           7.10.1    ApplyingChanges   68m

After making these changes:

[ec2-user@ip-192-168-4-130 ~]$ sudo docker run -it --rm ubuntu bash -c "cat /proc/sys/fs/inotify/max_user_watches"
Unable to find image 'ubuntu:latest' locally
latest: Pulling from library/ubuntu
da7391352a9b: Pull complete
14428a6d4bcd: Pull complete
2c2d948710f2: Pull complete
Digest: sha256:c95a8e48bf88e9849f3e0f723d9f49fa12c5a00cfc6e60d2bc99d87555295e4c
Status: Downloaded newer image for ubuntu:latest
524288

[ec2-user@ip-192-168-4-130 ~]$ cat /proc/sys/vm/max_map_count
524288

Was able to successfully start elastic search

kubectl get elasticsearch


NAME         HEALTH   NODES   VERSION   PHASE   AGE
quickstart   green    1       7.10.1    Ready   7m6s

I read through some documentation and couldn't find any negative side affects of increasing these params out of the box, it depends on the applications being run and if they are trying to exhaust these limtis.

https://unix.stackexchange.com/questions/13751/kernel-inotify-watch-limit-reached
https://www.suse.com/support/kb/doc/?id=000016692

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[patrickleet]

I see this was merged, but not a corresponding release since then - when will a release that includes this be made?