# Dropped HTTP Connections when Indexing **URL:** \ **Category:** Elasticsearch\ **Created:** [July 19, 2014, 3:23am UTC](https://discuss.elastic.co/t/dropped-http-connections-when-indexing/18747 "2014-07-19T03:23:23Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![tbrianjones](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/tbrianjones/32/1402_2.png) [@tbrianjones](https://discuss.elastic.co/u/tbrianjones)\ **Post date:** [July 19, 2014, 3:23am UTC](https://discuss.elastic.co/t/dropped-http-connections-when-indexing/18747/1 "2014-07-19T03:23:23Z")
I'm trying to scale my indexing for the first time, and I'm running into connections problems. I reach a scale where cURL connections from my indexers start getting cURL7 errors ( connect failed ). It looks like ES just stops accepting all HTTP connections for a period of time. I cannot find the root cause. I'm running on an Amazon C3.4XL. The processors are not maxed, memory is not maxed, IO is not showing issues. I'm not seeing problems in the ES log, but I'm not sure I have logging fully enabled. I've tried increasing the thread\_pool for the indexer, and that doesn't help. I'm not seeing any rejected connections there. I'm at a loss. The closest I can get is a guess using data from Bigdesk. When the number HTTP channels starts exceeding the number of transport channels, I start to see the problem emerge. I have no idea if this is related, but it's the only metric I've traced that seems correlated. Thoughts? -- 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). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/0fd75b96-3c00-47f1-9a59-3c9707f38734%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/0fd75b96-3c00-47f1-9a59-3c9707f38734%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![spinscale](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/spinscale/32/25011_2.png) [@spinscale](https://discuss.elastic.co/u/spinscale)\ **Post date:** [August 4, 2014, 7:55am UTC](https://discuss.elastic.co/t/dropped-http-connections-when-indexing/18747/2 "2014-08-04T07:55:26Z")
Hey, are you using HTTP keep alive connections? If not consider switching to them, as reopening a new TCP connection not only results in high latencies but also removes file handle resources from the elasticsearch process (the number of open files). if your client/language does not support this, you should either use nginx or at least try to use bulk operations in order to create less TCP connections, however this is just a workaround. --Alex On Sat, Jul 19, 2014 at 5:23 AM, Brian Jones [tbrianjones@gmail.com](mailto:tbrianjones@gmail.com) wrote: > I'm trying to scale my indexing for the first time, and I'm running into > connections problems. I reach a scale where cURL connections from my > indexers start getting cURL7 errors ( connect failed ). It looks like ES > just stops accepting all HTTP connections for a period of time. I cannot > find the root cause. > > I'm running on an Amazon C3.4XL. The processors are not maxed, memory is > not maxed, IO is not showing issues. I'm not seeing problems in the ES > log, but I'm not sure I have logging fully enabled. I've tried increasing > the thread\_pool for the indexer, and that doesn't help. I'm not seeing any > rejected connections there. I'm at a loss. > > The closest I can get is a guess using data from Bigdesk. When the number > HTTP channels starts exceeding the number of transport channels, I start to > see the problem emerge. I have no idea if this is related, but it's the > only metric I've traced that seems correlated. > > Thoughts? > > -- > 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). > To view this discussion on the web visit > [https://groups.google.com/d/msgid/elasticsearch/0fd75b96-3c00-47f1-9a59-3c9707f38734%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/0fd75b96-3c00-47f1-9a59-3c9707f38734%40googlegroups.com) > [https://groups.google.com/d/msgid/elasticsearch/0fd75b96-3c00-47f1-9a59-3c9707f38734%40googlegroups.com?utm\_medium=email&utm\_source=footer](https://groups.google.com/d/msgid/elasticsearch/0fd75b96-3c00-47f1-9a59-3c9707f38734%40googlegroups.com?utm_medium=email&utm_source=footer) > . > For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). -- 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). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/CAGCwEM-QZCWND%2B0FuYNEZdjK\_5izSaZUMFmB\_TyBTTuFSyZB3g%40mail.gmail.com](https://groups.google.com/d/msgid/elasticsearch/CAGCwEM-QZCWND%2B0FuYNEZdjK_5izSaZUMFmB_TyBTTuFSyZB3g%40mail.gmail.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**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, 1:11am UTC](https://discuss.elastic.co/t/dropped-http-connections-when-indexing/18747/3 "2017-07-06T01:11:13Z")