<p>Deployed an <code>Elasticsearch</code> on <code>GKE</code>. ECK has 3 master and 2 data nodes. When creating an index with 1 shard and 1 replica getting 400 error response when the shard count reached 1000.</p>
<p>Is it possible to increase the shard count? Please suggest a way to increase the shards count.</p>
<p><strong>Error details</strong></p>
<pre><code>Invalid NEST response built from a unsuccessful (400) low level call on PUT: /t-2af14520-e76d-4091-a51d-1c89cf990e97
Audit trail of this API call:
[1] BadResponse: Node: http://eck.com/ Took: 00:00:00.2833118
OriginalException: Elasticsearch.Net.ElasticsearchClientException: Request failed to execute. Call: Status code 400 from: PUT /t-2af14520-e76d-4091-a51d-1c89cf990e97. ServerError: Type: illegal_argument_exception Reason: &quot;Validation Failed: 1: this action would add [2] total shards, but this cluster currently has [2000]/[2000] maximum shards open;&quot;
Request:
&lt;Request stream not captured or already read to completion by serializer. Set DisableDirectStreaming() on ConnectionSettings to force it to be set on the response.&gt;
Response:
&lt;Response stream not captured or already read to completion by serializer. Set DisableDirectStreaming() on ConnectionSettings to force it to be set on the response.&gt;
</code></pre>

<p>You can change the shard number as follows. Refer <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/cluster-update-settings.html" rel="nofollow noreferrer">Cluster update settings API</a> for more details. I recommend that you apply it after test.</p>
<pre><code>PUT /_cluster/settings
{
    &quot;persistent&quot; : {
        &quot;cluster.max_shards_per_node&quot; : 3000
    }
}
</code></pre>
