Broken Failovers?

[Glenn Satchell]

>Date: Tue, 1 Apr 2008 20:58:53 -0400
>From: "Jonathan Brockmeier" <brockj at hope.edu>
>To: dhcp-users at isc.org
>Subject: Broken Failovers?
>
>I think I have found out that I have been running with broken failover for
>over a year:
>
>From Server A:
>failover peer "PEERNAME" state {
>  my state normal at 4 2008/03/20 12:49:19;
>  partner state normal at 1 2007/02/12 19:41:32;
>}
>
>From Server B:
>failover peer "PEERNAME" state {
>  my state normal at 4 2008/03/20 12:49:28;
>  partner state normal at 1 2007/02/12 19:41:48;
>  mclt 600;
>}

This is a feature :) The partner state date is filled in the first time
the lease file is written, and then nothing ever refers to it again. So
your failover isn't broken. I'm sure that if you search the archives
for "partner state normal" you'll find a few references.

If you look in the syslog file (varies with different operating
systems) you'll see what the current state is.

>Also it looks like when I get "pool request" messages the leases that seemed
>to be moved go into a state that they are locked for awhile (same on both
>servers)
>lease aaa.bbb.ccc.ddd {
>  starts 2 2008/04/01 20:08:04;
>  ends 2 2008/04/01 18:23:13;
>  tstp 2 2008/04/01 18:23:13;
>  tsfp 2 2008/04/01 20:08:04;
>  cltt 2 2008/04/01 18:13:13;
>  binding state backup;
>  hardware ethernet 00:c0:17:31:38:8b;
>  uid "\001\000\300\02718\213";
>}
>
>I would assume due to state 4 or is this related to some of the failover bug
>fixes since 3.0.3?
>
>If this is related to failover recovery not working for over a year, what is
>the best way to recover since the servers are "working" for most clients
>most of the time.

binding state backup means that the lease is available to be allocated
by the secondary. That's quite normal. Different releases have juggled
this around a bit, but since about 3.0.5 (I think) it tries to leave
leases with the one host, rather than bouncong them between the two
servers.

The dhcpd.leases man page explains what all the fields are.

regards,
-glenn