# Performance / Multiple TransportClients question **URL:** \ **Category:** Elasticsearch\ **Created:** [April 11, 2013, 11:21am UTC](https://discuss.elastic.co/t/performance-multiple-transportclients-question/11547 "2013-04-11T11:21:03Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Per\_Ekman](https://avatars.discourse-cdn.com/v4/letter/p/e9bcb4/32.png) [@Per\_Ekman](https://discuss.elastic.co/u/Per_Ekman)\ **Post date:** [April 11, 2013, 11:21am UTC](https://discuss.elastic.co/t/performance-multiple-transportclients-question/11547/1 "2013-04-11T11:21:03Z")
Hi I'm running a cluster consisting of one load-balancing node and two data-nodes. Currently I'm trying to fill the cluster with a lot of data, and for that we have a threaded Java program, using TransportClients to index data on port 9300. This program is run with 8 threads trying to index data at the same time. We have then run another 8 threads from another computer, starting to index data in the cluster. We then see response times increase / performance decrease quite a lot. My first questions: Are there limitations on number of transport clients to connect to a cluster (on port 9300)? Is there any configuration I should consider? In paramedic I http.current\_open hold a lot of connections. Is there a limit there? /Per -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![jprante](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jprante/32/44941_2.png) [@jprante](https://discuss.elastic.co/u/jprante)\ **Post date:** [April 11, 2013, 1:58pm UTC](https://discuss.elastic.co/t/performance-multiple-transportclients-question/11547/2 "2013-04-11T13:58:53Z")
If you connect transport clients to the cluster, you should connect to all of the available data nodes for better network load distribution. Note, a TransportClient can use many connections, it is not a 1:1 connection model. A client uses netty-based connection and thread pools which are scalable into the ten- or even hundredthousands of simultaneios connections. There is no limit of connections on port 9300. If you observe slowdowns, it may be your setup, or your node activity/capacity. If you observe many open files/sockets, it may be that you are not using persistent/ reuable socket connections, or you are opening/closing sockets too fast which is not required with ES. Jörg Am 11.04.13 13:21, schrieb Per Ekman: > Hi > > I'm running a cluster consisting of one load-balancing node and two > data-nodes. Currently I'm trying to fill the cluster with a lot of > data, and for that we have a threaded Java program, using > TransportClients to index data on port 9300. This program is run with > 8 threads trying to index data at the same time. We have then run > another 8 threads from another computer, starting to index data in the > cluster. We then see response times increase / performance decrease > quite a lot. My first questions: > > Are there limitations on number of transport clients to connect to a > cluster (on port 9300)? Is there any configuration I should consider? > In paramedic I http.current\_open hold a lot of connections. Is there a > limit there? > > /Per -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 2:41am UTC](https://discuss.elastic.co/t/performance-multiple-transportclients-question/11547/3 "2017-07-06T02:41:34Z")