[Pacemaker] Antwort: IPaddr2 resource IP unavailable on 'lo' interface for brief period after start

alexander.krauth at basf.com alexander.krauth at basf.com
Mon Aug 29 04:50:33 EDT 2011

"Patrick H." <pacemaker at feystorm.net> schrieb am 27.08.2011 10:22:08:
> [Pacemaker] IPaddr2 resource IP unavailable on 'lo' interface for brief 
period after start
> So the issue is that whenever I start up an IP with an IPaddr2 resource, 
the IP is unavailable when attempting to connect via lo interface for 
approximately 21 seconds after the resource is started.
> What I am doing is starting up the IP resource, and then I have another 
resource that tries to start, but prior to starting it does a status check 
by connecting to that IP on a TCP port to see if 
> the service is up. And if it isnt up, then it starts it. Well I should 
immediately get a 'connection refused' message as the service isnt 
running, however I dont. Instead the resource times out as I
> have startup timeout set to 20 seconds, and connection attempts wont 
give 'connection refused' until after 21 seconds. However I can try to 
connect from another host on the network and I immediately
> get 'connection refused' as expected, even while the box trying to 
connect to itself is still not working.
> But it gets even more interesting. I did a tcpdump on eth0 interface 
(the interface the IPaddr2 resource IP is on) the box running the 
resources and I get the following when resources start up 
> (presumably triggered by the box trying to connect for the status 
>   01:12:21.423330 arp who-has (Broadcast) tell
>   01:12:22.428523 arp who-has (Broadcast) tell
>   01:12:23.429342 arp who-has (Broadcast) tell
> Notice as my box seems to be having a slight identity crisis 
( is the IPaddr2 resource)
> Also when I tcpdump on the lo interface I get the following
>   01:15:41.837719 IP > S 
1770941237:1770941237(0) win 32792 <mss 16396,sackOK,timestamp 190131056 
0,nop,wscale 4>
>   01:15:44.845531 IP > S 
1770941237:1770941237(0) win 32792 <mss 16396,sackOK,timestamp 190134064 
0,nop,wscale 4>
> Which indicates that the box clearly isnt responding ( is 
the box's normal ip)
> As mentioned earlier, after 21 seconds I start getting 'connection 
refused' when attempting to connect. The packets are still going over the 
lo interface at this point, so nothing changes. 
> Additionally an arp reply never does come back on eth0 or lo, it just 
magically starts working.
> I could bump up my timeout to something higher, but i would really 
prefer to get this issue 

Hm, just an idea. Did you try:

ip route flush cache

There is also the "flush_routes" parameter in ipaddr2, but this is only in 
the "stop" method. Seams your issue is somehow different.


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