Shards for three node cluster

Elastic Stack Elasticsearch
1

Hi Team,

I have three node cluster and my current shard setting is 2 primary and 1 replica so in total, 4 shards for three node cluster.

In this case, a single node is having one extra shard everytime?

Can i have 1 primary and 2 replica shards? So that each node will have only one shard to have less storage footprint.

Also, it is mentioned in documentation that we can reduce no. of shards for rollover index, is it possible with three node cluster and above current shard setting (2 primary,1 replica) to have less storage footprint.

I am asking these questions to save storage space.

Thanks,

2

Hi All,

Can someone please reply.

3

Please have patience when asking questions, we don't offer SLAs on questions here and you only asked this a day before bumping it.

If you are looking to reduce disk use then you should be looking at mappings and compression settings, not really shard counts.

Yes you can.

4

Can someone confirm that there will be no disadvantage of having 1 primary and 2 repliacs on three node cluster?
Am i missing something.
Here the aim is not really performance (paraller read etc.) but to have shards equally spread on each node ( no extra shard allocated but in above case currently its happening).

Thanks,

5

It'll depend on the size of the index, but there's nothing wrong with that.

6

Just trying to dig more to see if we get any side effects after changing as above,

If i have 100gb index with 2 primary shaeds and 1 replica (current setup),

Each primary shard will have 50gb data and each replica will also have 50gb so in total, all will consume 200gb.

If i have 100gb index with 1 primary shaeds and 2 replicas (desired setup)

Primary will have 100gb and each replica will also have 100gb so in total, it will be 300gb. So here space consumption is more.

Is this understanding correct?

7

That's correct.

8

This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.