Elastic queries slows down when there multiple requests

Hi,

We are running into a strange issue . When there are multiple queries to elastic even on different index the response from elastic slows down.

More detail :

  1. We have a elastic index with 1750K records. to get the results faster we are running a 5 threads on elastic transport client to get the results.
  2. In the same elastic node there is another elastic index with 200K records. It has has 5 threads to get the data from elastic.

When they run independently we are able to get the results in 20-23 seconds.
But in some cases when both are fired together the results comes back in 5-10 minutes.

Can you help us debug it me as i am not having expertise in configuring elastic.

Thanks and regards,
Umesh Paliwal