# Why timeout of agent, load balanced and apm server should be incremental?

**URL:** <https://discuss.elastic.co/t/why-timeout-of-agent-load-balanced-and-apm-server-should-be-incremental/206247>\
**Category:** APM\
**Tags:** server\
**Created:** [November 2, 2019, 4:50pm UTC](https://discuss.elastic.co/t/why-timeout-of-agent-load-balanced-and-apm-server-should-be-incremental/206247 "2019-11-02T16:50:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Evgeni\_Dzhelyov](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/evgeni_dzhelyov/32/56047_2.png) [@Evgeni\_Dzhelyov](https://discuss.elastic.co/u/Evgeni_Dzhelyov)\
**Post date:** [November 2, 2019, 4:50pm UTC](https://discuss.elastic.co/t/why-timeout-of-agent-load-balanced-and-apm-server-should-be-incremental/206247/1 "2019-11-02T16:50:22Z")

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This is purely an educational question. We hit the well known [I/O timeout](https://www.elastic.co/guide/en/apm/server/7.4/common-problems.html#io-timeout) problem due to the following setup of timeouts:

```auto
Agent | Load Balancer | APM server
10s | 60s | 30s

```

After changing to `10s – 15s – 30s` everything works as expected.

I tried to figure out why it doesn't work in the first place, but neither my limited networking knowledge, neither googling and source reading helped me. I would appreciate it if you could explain why this is happening?

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**Author:** ![basepi](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/basepi/32/53056_2.png) [@basepi](https://discuss.elastic.co/u/basepi)\
**Post date:** [November 11, 2019, 11:07pm UTC](https://discuss.elastic.co/t/why-timeout-of-agent-load-balanced-and-apm-server-should-be-incremental/206247/2 "2019-11-11T23:07:14Z")

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I'm actually not on the server team but this piqued my interest and has gone unanswered, so I investigated a little.

Basically, the [ELB timeout is how long it tries to keep open the connection for re-use](https://aws.amazon.com/blogs/aws/elb-idle-timeout-control/). If the server "hangs up" first, though, then when that connection tries to be re-used, you'll get an error. I'm pretty sure it's that simple, though I'm not an expert in this area.

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [December 2, 2019, 7:07pm UTC](https://discuss.elastic.co/t/why-timeout-of-agent-load-balanced-and-apm-server-should-be-incremental/206247/3 "2019-12-02T19:07:20Z")

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