[lvs-users] LVS and stale connections

Joseph Mack NA3T jmack at wm7d.net
Tue Mar 31 15:04:41 BST 2009


On Tue, 31 Mar 2009, Fabio Coatti wrote:

> Basically, the scenario is the following: 5 servers (RIP), 
> balanced with ipvs on linux 2.6.23, DR is used. All works 
> just fine, but if for some reasons the real servers 
> freezes and need reboot, ipvs keeps as "alive" all the 
> connections so the balancing is not correctly done.

ipvs has no way of knowing that a machine has been rebooted, 
so this is the expected behaviour. Health checking is all 
external to ipvs. Since in LVS-DR the director doesn't see 
the returning packets, it has to guess when connections 
expire, and you've set a long timeout.

Either

o use the -SH scheduler to direct clients to the same 
database server and return the timeouts to the default 
period.

o use one of the ioctls that Horms wrote to handle crashed 
realservers when ipvs is using persistence. These clear out 
the connection table

Joe

-- 
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
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Homepage http://www.austintek.com/ It's GNU/Linux!




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