On 07/19/2017 04:56 AM, Yann Ylavic wrote:
The comment in proxy_fcgi says:
/* This scheme handler does not reuse connections by default, to
* avoid tying up a fastcgi that isn't expecting to work on
* parallel requests. But if the user went out of their way to
* type the default value of disablereuse=off, we'll allow it.
So could it be an fpm/application bug, maybe also suggested in the
link provided by Luca where it's also said that the issue happens with
other servers too (e.g. nginx)?
I was able to reproduce a hang with PHP-FPM and enablereuse=on, but I
don't think it's UDS-specific. (Haven't tried with TCP yet, though.)
If the maximum number of connections opened by httpd to PHP-FPM exceeds
the maximum number of requests that FPM is configured to handle in
parallel, the extra connections will be queued up for later. But since
we're no longer closing connections once a request finishes, those
queued connections will hang until we hit the ProxyTimeout. It's
important for admins to match the Proxy's max= parameter with their
backend's configuration, which is something you didn't have to worry
about as much with enablereuse=off.
I have still not been able to reproduce the "messed up POSTs" that other
people are reporting with UDS+enablereuse.