EsRejectedExecutionException in elasticsearch for parallel search

Question

I am querying elasticsearch for multiple parallel requests using single transport client instance in my application.

I got the below exception for the parallel execu

Answer 1

Maybe it sounds strange, but you need to lower the parallel searches count. With that exception, Elasticsearch tells you that you are overloading it. There are some limits (at thread count level) that are set in Elasticsearch and, most of the times, the defaults for these limits are the best option. So, if you are testing your cluster to see how much load it can hold, this would be an indicator that some limits have been reached.

Alternatively, if you really want to change the default you can try increasing the queue size for searches to accommodate the concurrency demands, but keep in mind that the larger the queue size, the more pressure you put on your cluster that, in the end, will cause instability.