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Re: unexpected code 35 (if tcp listen backlog is full)

From: Daniel Stenberg <>
Date: Tue, 16 Jan 2018 08:09:07 +0100 (CET)

On Mon, 15 Jan 2018, Michael Kilburn wrote:

> It doesn't seem to work for me -- I've crated a shared cache of easy
> handles, after thread is done sending data, it returns handle (CURL*) into
> cache (actually, stack). But on server side accept queue size is always
> 20-30 while client is sending data (and performance has barely changed).

I'm sorry but I don't understand what you're trying to achieve nor how you do

> curl_easy_setopt(CURLOPT_WRITEFUNCTION, ...) // func discards incoming
> data

I trust this callback return the correct value still? Otherwise it'll probably
cause the connection to get closed.

> curl_easy_perform()

In the easy interface (that you are using when _easy_perform is called), the
connection cache is held in the easy handle so unless you share the connection
cache between handles you must make sure to re-use a handle that was
previously used to communicate with the same host as otherwise it won't have
the previous connection in its cache...

> Maybe one of these options prevent tcp connection (and related TLS session
> key) from being reused?

Connections can also get closed by the server's decisions.

Received on 2018-01-16