# CPU Usage 100%
**URL:** https://discuss.elastic.co/t/cpu-usage-100/34607
**Category:** Elasticsearch
**Created:** [November 15, 2015, 3:56am UTC](https://discuss.elastic.co/t/cpu-usage-100/34607 "2015-11-15T03:56:57Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@jiten.savla](https://discuss.elastic.co/u/jiten.savla)
#### Post date: [November 15, 2015, 3:56am UTC](https://discuss.elastic.co/t/cpu-usage-100/34607/1 "2015-11-15T03:56:57Z")
We have 3 node cluster each node having configurations - 4 CPU (Intel(R) Xeon(R) CPU @ 2.30GHz) and 15 GB RAM. We have indexed 150M documents on this cluster. We have seen that without firing any query the CPU usage on all 3 x 4 = 12 CPU is 100%. Why would it be so? Is there a way to monitor whats the load on this nodes leading to it?
Also the RAM is caching a lot of data, could that slow down the process. See RAM usage - ]
root@elastic-server-instance-3:~# free -m
total used free shared buffers cached
Mem: 15040 14762 277 0 152 8725
-/+ buffers/cache: 5884 9155
Swap: 0 0 0
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### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [November 16, 2015, 3:35am UTC](https://discuss.elastic.co/t/cpu-usage-100/34607/2 "2015-11-16T03:35:00Z")
Install Marvel and you should be able to see what is happening.
As for the memory use, don't panic! Check out [https://www.elastic.co/guide/en/elasticsearch/guide/current/heap-sizing.html#\_give\_half\_your\_memory\_to\_lucene](https://www.elastic.co/guide/en/elasticsearch/guide/current/heap-sizing.html#_give_half_your_memory_to_lucene)
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 5, 2017, 11:38pm UTC](https://discuss.elastic.co/t/cpu-usage-100/34607/3 "2017-07-05T23:38:19Z")