Disk I/O for master-only node?

[YuWatanabe]

Hello.

I would like to get advice for hardware requirements for dedicated-master node with es v 6.3.2.
This is my first time setting up dediciated master-node so I appreciate if I could get advice.

I have read below 2 articles but I was not sure about how frequent the cluster state is update to the disk.

Master-eligible Node

What is the ES cluster size that requiers a dedicated master node?

Currently, I am building new cluster and planning to set up 3 dedicated-master node with below hw. Indexing rate for data nodes are estimated up to 50GB/day using 5 data nodes.

1. CPU: Xeon Bronze 3106 (8 cores , 1.7 GHz)
2. RAM: 32 GB
3. HDD: 300 GB SAS 15000RPM *2 (RAID1)

For RAM , I see that 4GB of heap is a starting line but planning to have little bit of room to scale up the heap size just in case. However for disks if cluster state is updated in some interval, is spinning-disk enough ? Or if cluster state is updated very frequently , should you use ssd?

Best Regards,
Yu Watanabe

[nik9000 (Nik Everett)]

The cluster state is updated when indices are created and when shards move from node to node and at times like that. But the cluster state is comparatively small so a spinning disk should be just fine.

[YuWatanabe]

@nik9000

Thank you for the useful advice.