# Identiying how Memory is being used in ES
**URL:** https://discuss.elastic.co/t/identiying-how-memory-is-being-used-in-es/85322
**Category:** Elasticsearch
**Created:** [May 11, 2017, 3:40am UTC](https://discuss.elastic.co/t/identiying-how-memory-is-being-used-in-es/85322 "2017-05-11T03:40:15Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Barto\_Rael](https://discuss.elastic.co/u/Barto_Rael)
#### Post date: [May 11, 2017, 3:40am UTC](https://discuss.elastic.co/t/identiying-how-memory-is-being-used-in-es/85322/1 "2017-05-11T03:40:15Z")
Hi All,
We are using 15 node cluster with 12 GB Heap Size allocated per node. We have set bootstrap.mlockall: true to avoid memory swapping.
When I am monitoring cluster via Marvel plugin then it is showing that all nodes are using 70-75% of JVM memory so I digged into metrics to measure where this memory is being used. We don't have defined property "indices.fielddata.cache.size" in configuration so there is no limit for fielddata memory size from us. I was expecting that entire JVM memory must be used by fielddata but it is not the case.
I checked the fielddata memory usage by "GET /\_nodes/stats/indices/fielddata" which is showing that each node is using 4 GB memory which is only 33% of total memory (12 GB) and count is evictions is 0.
Could anyone help me to identify how this memory is being utilized by ES?
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### Author:  [@Hanish\_Bansal](https://discuss.elastic.co/u/Hanish_Bansal)
#### Post date: [May 13, 2017, 2:58am UTC](https://discuss.elastic.co/t/identiying-how-memory-is-being-used-in-es/85322/2 "2017-05-13T02:58:07Z")
Any update of above query?
What is default size of field data cache? is it same as total Heap size or not ?
In system logs, we are getting below logs which indicates that most of memory is used by old GC pool.
[2017-05-13 06:45:42,317][WARN][monitor.jvm] [node2] [gc][old][6851992][21024] duration [11.2s], collections [1]/[11.7s], total [11.2s]/[27.5m], memory [11.3gb]-\>[8.3gb]/[14.9gb], all\_pools {[young] [450.6mb]-\>[49.3mb]/[532.5mb]}{[survivor] [66.5mb]-\>[0b]/[66.5mb]}{[old] [10.8gb]-\>[8.2gb]/[14.3gb]}
Can we do something to clear GC old pool memory?
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [June 10, 2017, 3:05am UTC](https://discuss.elastic.co/t/identiying-how-memory-is-being-used-in-es/85322/3 "2017-06-10T03:05:05Z")
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