is ElasticClient thread safe? (connection pooling)

[janghwan]

Hi guys.
I wonder what's the best usage of ElasticClient
Is it okay - in terms of performance - to call ElasticClient.remote() every time I need a client?
Or should I cache a singleton object and share among threads?

[andrestc]

We are currently using it as a singleton object. I think all that ElasticClient does is create an org.elasticsearch.client.transport.TransportClient. It seems that he keeps a pool of threads for sending the requests over the cluster; so i don't think its a good idea to call it every time when making a request.

[sksamuel]

@janghwan Definitely cache it. The reason is an Elasticsearch client is a clever beast. It pings the cluster to become cluster-aware so it can route queries to the right nodes. Each time you create one there's this small overhead. In addition to the internal thread pools it creates (about 30 threads).

[janghwan]

Thanks! @andrestc @sksamuel

[fpopic]

object Elastic4sUtils {

  val client = ElasticClient.transport("elasticsearch://localhost:9300")

}

Is that good example of it or ?

val session = Elastic4sUtils.client