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akka-streamakka-http

Why HttpEntity.toStrict has no variant without a timeout?

Akka-http HttpEntity.toStrict is a way to consume an entity when the full body is required for later processing, but it does not have a variant without a timeout parameter.

It is quite easy to consume a body with entity.dataBytes.runReduce(_ ++ _) which does not have a timeout. But what are the consequences?

Question #1

If HttpEntity.toStrict times out, does akka-http close the connection immediately? Or still consuming the body discarding the data? Or what?

Question #2

If a body is consumed without a timeout (like with the above code), and the connection "hangs", are there any applicable timeout parameters in akka-http configuration? For client? For server? If connection "hangs" before starting the body, are there any applicable timeout parameters?

Question #3

If there is no global timeout, why HttpEntity.discardBytes does not have a similar timeout parameter?

Solution

  • If HttpEntity.toStrict times out, does akka-http close the connection immediately? Or still consuming the body discarding the data? Or what?

    It'd close the connection AFAIR, since it's counted as a failure which propagates down the stream (as well as up as a cancellation).

    If a body is consumed without a timeout (like with the above code), and the connection "hangs", are there any applicable timeout parameters in akka-http configuration? For client? For server? If connection "hangs" before starting the body, are there any applicable timeout parameters?

    There's a full section about timeouts in the documentation: http://doc.akka.io/docs/akka-http/current/scala/http/common/timeouts.html These include idle-timeouts which would trigger when connections "hang".

    If there is no global timeout, why HttpEntity.discardBytes does not have a similar timeout parameter?

    There are global safety timeouts, most notably request timeouts and idle timeouts. All documented in the docs. http://doc.akka.io/docs/akka-http/current/scala/http/common/timeouts.html

    discardBytes is really just convenience when you don't care at all about the entity. I guess we could add an overload with a timeout, it's the first time anyone asked for it to be honest though. You can easily add timeouts using the Akka Streams timeout stages anyway.