How can I check indices.memory.index_buffer_size parameter is effectively working in elasticsearch?

Question

I have elasticsearch cluster, and I add indices.memory.index_buffer_size parameter in elasticsearch.yml file. I set this parameter be 70%. And then the cluster began to indexing. After all, I reset this parameter be 10%, and I restart the elasticsearch.

My question is how can I check my settings are working?

Answer 1

I think (but I'm not positive) that it should show up in the nodes information API. Try this:

curl -XGET "http://localhost:9200/_nodes?clear&all"

Answer 2

You can use the /_nodes API, but what I found puzzling was that the value for the setting is not returned if you are using the default. But once you change it (in elasticsearch.yml) and rebounce your cluster, it >will< appar in the output of the /_nodes API call.

to illustrate.

• install elastic search and start cluster.
• curl 'http://localhost:9200/_nodes' | grep index_buffer_size # no match
• change value of index_buffer_size to other than default and bounce cluster
• curl 'http://localhost:9200/_nodes' | grep index_buffer_size # Match !

My guess is that this is the case for any .yml setting, not just this one (although i have not verified that theory).