# Cluster configuration, shards, and replica **URL:** \ **Category:** Elasticsearch\ **Created:** [May 14, 2020, 8:52am UTC](https://discuss.elastic.co/t/cluster-configuration-shards-and-replica/232587 "2020-05-14T08:52:02Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![carmine.fabrizio](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/carmine.fabrizio/32/71788_2.png) [@carmine.fabrizio](https://discuss.elastic.co/u/carmine.fabrizio)\ **Post date:** [May 14, 2020, 8:52am UTC](https://discuss.elastic.co/t/cluster-configuration-shards-and-replica/232587/1 "2020-05-14T08:52:03Z")
Hi, I have a cluster of 9 nodes, 3 master-hot, 3warm, and 3 cold, they have the same amount of ram 32GB but different disk-space, the hot is on SSD, the others on the mechanic. I haven't followed the ratio best practice like 1:30 for the hot, 1:160 warm, and 1:250 cold, but I do have enough space like 250TB across all the nodes. Now I am ingesting something like 1TB ~ 1.3TB od data per day, quite a lot, and I thought my cluster was enough but it does not look like, coz I am having issues when it comes to search and so on. I have allocated 18 primaries shards on hot and 6 on warm/cold using the default replica:1. I really do not know what kind of action should I take in order to optimize my cluster, any help on this? Shall I increase my replica in order to increase the performance search? Shall I increase the number of shards? but I do not think so because most of the time I have "Waiting for all shard copies to be active" or another type of warning related to the shards. Any help will be much appreciated. ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [May 14, 2020, 9:45am UTC](https://discuss.elastic.co/t/cluster-configuration-shards-and-replica/232587/2 "2020-05-14T09:45:34Z")
That sounds like a very small cluster given the ingest volume and I would expect you to suffer from heap pressure which leads to performance problems. I would recommend you upgrade to Elasticsearch 7.7 which contains some [changes that dramatically reduce heap usage](https://www.elastic.co/blog/elasticsearch-7-7-0-released). If you for some reason are unable to upgrade I would recommend watching [this webinar](https://www.elastic.co/webinars/optimizing-storage-efficiency-in-elasticsearch). ---
**Author:** ![carmine.fabrizio](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/carmine.fabrizio/32/71788_2.png) [@carmine.fabrizio](https://discuss.elastic.co/u/carmine.fabrizio)\ **Post date:** [May 14, 2020, 10:40am UTC](https://discuss.elastic.co/t/cluster-configuration-shards-and-replica/232587/3 "2020-05-14T10:40:45Z")
indeed about the upgrade but ain't gonna happen soon, I checked the webinar and they explain pretty much well the approach warm/hot/cold, the only difference is that I do not have dedicate master, I mean my master are hot nodes as well. How can I check the volume of data that my cluster can ingest? it is small indeed, but I only noted now after almost 3 months of usage that it is small. Thanks for the reply btw. ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [May 14, 2020, 11:01am UTC](https://discuss.elastic.co/t/cluster-configuration-shards-and-replica/232587/4 "2020-05-14T11:01:33Z")
If you have monitoring installed I would recommend starting by looking at heap usage across your nodes and ensure this looks OK. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [June 11, 2020, 11:01am UTC](https://discuss.elastic.co/t/cluster-configuration-shards-and-replica/232587/5 "2020-06-11T11:01:36Z")
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