Master node on Hot node in hot -warm architecture?

[YuWatanabe]

I understand that as it is described in blog , master node should be deployed as dedicated master nodes. I want to use the warm node to have flexible storage volume with low cost.

However, since I am preparing only 5 nodes, I would like to know if it is possible to build master on hot nodes.

My requirement is ,

Store logs for 1 year
100 GB events / day
2500 events / sec

My architecture ,
node1 hot (SAS (RAID0+1) or SSD(RAID0+1)) + master?
node2 hot (SAS (RAID0+1) or SSD(RAID0+1)) + master?
node3 hot (SAS (RAID0+1) or SSD(RAID0+1)) + master?
node4 warm ( possibility of attaching to external storage)
node5 warm ( possibility of attaching to external storage)

• I chose external storage since it would be more flexible to increase the disk size

All incoming logs to elasticsearch will come from logstash.

[warkolm (Mark Walkom)]

Do you want to run two instances on the same host?

[YuWatanabe]

@warkolm

Thanks for the reply. Short answer to your question is No.

So, are hot and warm nodes dedicated data nodes and need to set node.master to false?

[warkolm (Mark Walkom)]

If you make the hot nodes master, and you get a big batch of messages and the current hot node that is also master hits high GC, what do you think will happen to the cluster?

[YuWatanabe]

Master nodes will have delay in its processing ( creating index, deleting index, track nodes) . Which will have instability with the cluster?

[warkolm (Mark Walkom)]

Yeah

Ideally you should have dedicated master nodes, but if not you just need to be aware of the risks you need to balance.

[YuWatanabe]

Thanks for the lesson! I like it.