In case of I have 30TB storage(6 spinning 5TB disks with stripe(raid 0)) and 64GB RAM x 4 nodes,
RAM is going insufficient but storage just used about 10%.
Indices have no replica.
To improve availability I have two options,
- set indices replica to 1.
- change disk raid to 1+0 ( 1mirror)
For 1, I worry about the lack of memory for the new replica shard.
(May replica shard will consume RAM amount of just like primary shard does, right?)
For 2, I heard mirroring is not recommend for es(they say just use replica!)
What is better option?
This is the current Heap status of one node.