ElasticSearch high CPU on merge threads

Elastic Stack Elasticsearch
1

Hi,

I am doing a bulk indexing every 10 minutes using logstash to send data to ElasticSearch. For almost 20 days everything went OK, but today I am getting the following issue:

  • ElasticSearch is using very high CPU , and when I am getting hot threads it seems that almost all of the big cpu thead are the Lucene merging threads.

  • My bulk indexing is lasting 4 times longer.

I am running 2 elasticsearch nodes on SSD disk.

Does anyone knows where the problem could come from ?

2

What version are you on?
Are there lots of deleted documents or segments?

3

I run ES version 2.2.1 and I dont delete docs at all

4

Are you updating a lot of documents?

5

Neither, basically I bulk index around 30000 docs in a new index every 10
minutes with no update/delete. My master node seems to be totally slower
than before. My search became slower as well. I really can t tell if it is
an ES or an hardware problem as I did a full cluster restart

6

Do you have Marvel installed to monitor your cluster? If not that'd be a good idea as it'll give you something to look at in terms of metrics.

7

I will install marvel and check this out. Thanks

8

Could not install Marvel but the problem is solved. The problem was with the server itself and not ElasticSearch. Could not detect exactly where it was from but a full server restart solved it.