Java Elasticsearch REST Client reuse or pooling

I can not seem to find any info related to the connection pooling of the java rest client. I found several articles about transport client but nothing about the rest.
We have a proxy server in front of ES cluster transforming requests. The version of the ES client is 5.2.2 and ES cluster is 2.4.4 . We are close to migrate the cluster to 5.2.2.
There was a new client built for every request. I changed that to a singleton RestClient. Is this the best approach? In fact method RestClose.close() never gets called. We call synchronous performRequest method.
Thanks any hints,


I believe pooling it is better. Internally it uses an async client that starts a few threads and stuff. If you find contention on those threads you can configure the client differently when you build it, I believe.

Reusing a single instance of RestClient is the way to go, also calling close it important when the application gets stopped. This is mentioned in our docs here:

The connection pooling is done internally in the underlying apache async http client. We increase by default the maxConnPerRoute to 10 and maxConnTotal to 30. That is just a guess on our end. You can always set your own values by providing a custom HttpClientConfigCallback that sets them using RestClientBuilder#setHttpClientConfigCallback.

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Thank you very much. I have implemented ServletContextListener that takes care of the client and sniffer close() calls during redeploy.

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