JVM setting

[elasticforme (Sachin)]

What should be prefer jvm option for cluster?
using elasicsearch java
three node x 100gig ram each, 20core each host

-Xms24g
-Xmx24g
-XX:+UseG1GC
-XX:G1ReservePercent=25
-XX:InitiatingHeapOccupancyPercent=30

or following which listed on oracle java document

-Xms24G
-Xmx24G  
-XX:+UseG1GC 
-XX:MaxGCPauseMillis=200 
-XX:ParallelGCThreads=20 
-XX:ConcGCThreads=5 
-XX:InitiatingHeapOccupancyPercent=70

data ingestion is about 800Million record a day of system metric via logstash
nothing else running in this systems except Elasticsearch
What other parameter needs to be set to make sure memory gets use properly and efficiently. I can test this out once I know something more.
I am very naive on java part

[DavidTurner]

By default Elasticsearch configures itself according to the machine on which it's running so it's best not to override any of these settings yourself. 800M documents per day is ~10k per second which is nowhere near the throughput that some benchmarks can achieve using the default settings, so you should be fine.

[elasticforme (Sachin)]

David,
so you saying does not matter what of above setting will not make much difference?

[DavidTurner]

No, I think it matters if you override any of these settings, it can make performance a lot worse to get it wrong. So don't do that. Let Elasticsearch set these things for you.

[elasticforme (Sachin)]

David you right.
so far I have never had to touch that and it was working beautifully.
but I have gone to Container/VM route and since then kibana dashboard loading is slow , very slow.
even though I have gone from ssd to nvme.
on host/vm level I can see the IO speed is more then four time, new system has faster cpu, network speed is also doubled.

hence I started playing around with jvm options.

[elasticforme (Sachin)]

which one is better performance. both are same cpu count / same memory

Node-1

-XX:+UseG1GC
-XX:NewSize=6g
-XX:MaxNewSize=6g
-XX:SurvivorRatio=6
-XX:TargetSurvivorRatio=70

Node -2
-XX:+UseG1GC
-XX:G1ReservePercent=25
-XX:InitiatingHeapOccupancyPercent=70
-XX:ConcGCThreads=5
-XX:ParallelGCThreads=10

I am just playing around with what I can find. and trying to understand this java memory stuff.