Node-level cluster.max_shards_per_node has no effect

[DaveCTurner]

We only look at the value of cluster.max_shards_per_node taken from the cluster metadata which, if unset, defaults to 1000:

elasticsearch/server/src/main/java/org/elasticsearch/indices/IndicesService.java

Line 1477 in d8417dc

int maxShardsPerNode = MetaData.SETTING_CLUSTER_MAX_SHARDS_PER_NODE.get(theseSettings);

This means that setting cluster.max_shards_per_node in elasticsearch.yml has no effect, but most other dynamic settings can also be set statically like this, so this caught me by surprise.

Relates #34021
Relates https://discuss.elastic.co/t/180785

[elasticmachine]

Pinging @elastic/es-core-features

[jasontedor]

Duplicates #40803

[verygreen]

So #40803 was closed because original report was about some non-default distro or some such.

But THIS ticket is about stock package you get from elastic theselves. So should we reopen this ticket instead? Open another one?

@jasontedor any advice? I jsut hit this problem on this package from the official repo:

# rpm -qi elasticsearch-7.3.2-1.x86_64
Name        : elasticsearch
Epoch       : 0
Version     : 7.3.2
Release     : 1
Architecture: x86_64
Install Date: Thu 12 Sep 2019 03:42:55 PM EDT
Group       : Application/Internet
Size        : 480100569
License     : Elastic License
Signature   : RSA/SHA512, Fri 06 Sep 2019 01:02:00 PM EDT, Key ID d27d666cd88e42b4
Source RPM  : elasticsearch-7.3.2-1-src.rpm
Build Date  : Fri 06 Sep 2019 10:55:26 AM EDT
Build Host  : packer-virtualbox-iso-1559162487
Relocations : /usr 
Packager    : Elasticsearch
Vendor      : Elasticsearch
URL         : https://www.elastic.co/
Summary     : Distributed RESTful search engine built for the cloud

[DaveCTurner]

@verygreen I think you're mistaken: #40803 is still open, and while it remains unresolved the workaround mentioned there should still work for you.

[verygreen]

Hm, I guess I was confused by the (currently) last comment that says closed, but that is a different ticket. Coupled with the previous one pointing at unsupported distro. Oh well, sorry about the false alarm then.