tree 1b094f5e802af28b58613cbbfa067b4ef951ff31
parent 9826c7781a25fbf9b84c8a139b28eaa395d16eb4
author Joseph Lynch <joe.e.lynch@gmail.com> 1431411934 -0700
committer Willy Tarreau <w@1wt.eu> 1432271260 +0200
encoding latin1

MEDIUM: backend: Allow redispatch on retry intervals

For backend load balancing it sometimes makes sense to redispatch rather
than retrying against the same server. For example, when machines or routers
fail you may not want to waste time retrying against a dead server and
would instead prefer to immediately redispatch against other servers.

This patch allows backend sections to specify that they want to
redispatch on a particular interval. If the interval N is positive the
redispatch occurs on every Nth retry, and if the interval N is negative then
the redispatch occurs on the Nth retry prior to the last retry (-1 is the
default and maintains backwards compatibility). In low latency environments
tuning this setting can save a few hundred milliseconds when backends fail.