How to detect a broken HTTP/TCP connection

[julien-f]

Hi,

My use case: I have a long HTTP request and I want to get an error when the connection fails instead of waiting indefinitely.

I tried to use keepAlive to help detecting whether the connection is up or not but it does not seem to be working.

Is there anything I'm missing?

Test repo: https://github.com/julien-f/socket-keepalive-tests/

[jasnell]

Questions like this are better directed at the nodejs/help repo (just as an fyi...)

keepAlive is an indication of whether the HTTP keep-alive mechanism is being used. It will not tell you the health of the current connection. Currently, there is no mechanism for determining if a connection is still active. You essentially need to attempt to read/write to it and deal with the error if it's not. You can set a timeout handler to set some action if there has been no activity within a given period of time, but that can miss disconnections also.

[julien-f]

My bad, I didn't know about this repo.

I'm talking about TCP keep-alive, not HTTP keep-alive 😉

I'm reluctant to use a timeout because I will miss the response and will not be able to tell if the RPC method I called was successful 😕

[Ginden]

Consider implementing some kind of heartbeat.

[julien-f]

Unfortunately I don't have any control on the HTTP server 😢

AFAIU, TCP is a connected protocol, I would be surprised if it is unable to detect a connection failure…

[bnoordhuis]

You'd be surprised. I'll close this out but if you want to continue the conversation, please move it over to the help repo.