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[lvs-devel] Sync connection timeout patch by Andy Gospodarek - made to w

Subject: [lvs-devel] Sync connection timeout patch by Andy Gospodarek - made to work better.
From: rumen at voicecho.com (Rumen Bogdanovski)
Date: Tue, 30 Oct 2007 17:47:49 +0200
Hi Simon,

> > 
> > Also I find it a good idea to sync the connections on ESTABLISHED to
> > FIN_WAIT transition, this will reduce the hanging time to 2 minutes and
> > we will avoid the short timeout if the conn is established.
> 
> I'm not oposed to this idea, but the synchronisation messages are
> sent via UDP, and thus an individual message may not arrive
> (though hopefully the majority of them will). I guess that
> your scheeme will work anyway: In the case where the packet arrives
> the state is updated; In the case where it doesn't then we
> are just back to where we are now, but that shouldn't happen
> very often (hopefully).
> 

I am sending you a patch that will make Andy's patch to work better. It
makes the master to sync connections on ANY->IP_VS_TCP_S_FIN_WAIT and
ANY->IP_VS_TCP_S_CLOSE state transition, in this case normally the
connection on the backup will be closed more or less at the same time as
on the master. If we are not lucky it will timeout with
IP_VS_TCP_S_FIN_WAIT timeout (2min), and if the backup misses even this
sync, bad luck, 15 minutes till the timeout...

I have also made the backup to set the state of any received connection
in order to make "ipvsadm -lnc" display its proper state and for Andy's
patch to set the proper timeout. This does not look to be a problem I
have spent more than half a day testing all this, and it looks working.

This patch should be applied over the patch I have sent before.

Tell me what do you think? Do you agree with my view to treat the
timeout problem on the backup?

regards,
Rumen

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