On Mon, May 02, 2011 at 04:04:56PM +0200, Andrew Beekhof wrote: > > Still, we may get a spurious failover in this case: > > > > reachability: > > +++++++++_____++++++++++++_____________________________ > > Node A monitoring intervals: > > + - + + + - - - - - > > Node B monitoring intervals: > > + + - + + - - - - - > > "dampening" interval: |---------| > > > > Note how the "dampening" helps to ignore the first network "glitch". > > > > But for the "permanent" network problem, we may get spurious failover: > > Then your dampen setting is too short or interval too long :-)
No. Regardless of dampen and interval setting. Unless both nodes notice the change at the exact same time, expire their dampen at the exact same time, and place their updated values into the CIB at exactly the same time. If a "ping node" just dies, then one node will always notice it first. And regardless of dampen and interval settings, one will reach the CIB first, and therefor the PE will see the connectivity change first for only one of the nodes, and only later for the other (once it noticed, *and* expired its dampen interval, too). Show me how you can work around that using dampen or interval settings. -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com _______________________________________________ Linux-HA mailing list Linux-HA@lists.linux-ha.org http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
