tree 65b6a7a839238c916b34aa92fb2f2055f8512916
parent f1e1cb463f12b2d5761ae97cd24f8b00b7d65340
author Krzysztof Piotr Oledzki <ole@ans.pl> 1200876846 +0100
committer Willy Tarreau <w@1wt.eu> 1200997746 +0100

[MEDIUM]: rework checks handling

This patch adds two new variables: fastinter and downinter.
When server state is:
 - non-transitionally UP -> inter (no change)
 - transitionally UP (going down), unchecked or transitionally DOWN (going up) -> fastinter
 - down -> downinter

It allows to set something like:
        server sr6 127.0.51.61:80 cookie s6 check inter 10000 downinter 20000 fastinter 500 fall 3 weight 40
In the above example haproxy uses 10000ms between checks but as soon as
one check fails fastinter (500ms) is used. If server is down
downinter (20000) is used or fastinter (500ms) if one check pass.
Fastinter is also used when haproxy starts.

New "timeout.check" variable was added, if set haproxy uses it as an additional
read timeout, but only after a connection has been already established. I was
thinking about using "timeout.server" here but most people set this
with an addition reserve but still want checks to kick out laggy servers.
Please also note that in most cases check request is much simpler
and faster to handle than normal requests so this timeout should be smaller.

I also changed the timeout used for check connections establishing.

Changes from the previous version:
 - use tv_isset() to check if the timeout is set,
 - use min("timeout connect", "inter") but only if "timeout check" is set
   as this min alone may be to short for full (connect + read) check,
 - debug code (fprintf) commented/removed
 - documentation

Compile tested only (sorry!) as I'm currently traveling but changes
are rather small and trivial.