[PATCH] Add a recycle_maxage attribute to backend definitions.

[Nils Goroll]

On 28/08/14 11:03, Martin Blix Grydeland wrote:

> Having a nanny thread for this part is in my opinion too much complexity for
> little gain.

I should have mentioned this in my first reply:

The main benefit I'd see is that currently closing BE conns depends on backend
requests being issued, so for instance no close will happen on a sick backends.

Despite the fact that I never experienced any real issues due to this, I really
don't like the fact that I have seen hundreds or even thousands of tcp conns in
CLOSE_WAIT and this has raised questions and serious worries of sysadmins we
work with. At least this is a real waste of file descriptors, which becomes
particularly apparent when migrating to different backends (without restarting
varnish).

I have not looked at the locking complexity question, but as we have one health
check thread per backend anyway, I'd be optimistic that the overhead could be
kept low to begin with.

Nils