[Pacemaker] SLES 11 SP3 boothd behaviour

[Sutherland, Rob]

All nodes in question NTP from the same time source (yes, we have run into synchronicity issues in the past).

Interestingly, increasing the lease from 60 seconds to 120 seconds did not affect the behaviour.

Rob

From: John Lauro [mailto:john.lauro at covenanteyes.com]
Sent: Monday, August 25, 2014 6:17 PM
To: Sutherland, Rob
Subject: Re: [Pacemaker] SLES 11 SP3 boothd behaviour

You probably already checked this, but just in case...

No experience at all with geo-redundancy, but this sounds suspiciously like it could be a time sync problem.  Have you tried something like "ntpq -np" on all 3 nodes and verify the offsets are all low (ie: < +/- 10) and times are in sync?
(Assuming you are running ntpd, and the process didn't stop.)

________________________________
From: "Rob Sutherland" <RSutherland at BroadViewNet.com<mailto:RSutherland at BroadViewNet.com>>
To: pacemaker at oss.clusterlabs.org<mailto:pacemaker at oss.clusterlabs.org>
Sent: Monday, August 25, 2014 3:43:34 PM
Subject: [Pacemaker] SLES 11 SP3 boothd behaviour
Hello all,

We’re in the process of implementing geo-redundancy on SLES 11 SP3 (version 0.1.0). We are seeing behavior in which site 2 in a geo-cluster decides that the ticket has expired long before actual expiry. Here’s an example time-line:

1 - All sites (site 1, site 2 and arbitrator) agree on ticket owner and expiry. i.e. site 2 has the ticket with a 60-second expiry:
Aug 25 10:07:10 linux-4i31 booth-arbitrator: [22526]: info: command: 'crm_ticket -t geo-ticket -S expires -v 1408975690' was executed
Aug 25 10:07:10 bb5Btas0 booth-site: [27782]: info: command: 'crm_ticket -t geo-ticket -S expires -v 1408975690' was executed
Aug 25 10:07:10 bb5Atas1 booth-site: [7826]: info: command: 'crm_ticket -t geo-ticket -S expires -v 1408975690' was executed

2 - After 48 seconds (80% into lease), all three nodes are still in agreement:
Site 2:
Aug 25 10:07:58 bb5Btas0 booth-site: [27782]: info: command: 'crm_ticket -t geo-ticket -S owner -v 2' was executed
Aug 25 10:07:58 bb5Btas0 booth-site: [27782]: info: command: 'crm_ticket -t geo-ticket -S expires -v 1408975738' was executed

The arbitrator:
Aug 25 10:07:58 linux-4i31 crm_ticket[23836]:   notice: crm_log_args: Invoked: crm_ticket -t geo-ticket -S owner -v 2
Aug 25 10:07:58 linux-4i31 booth-arbitrator: [22526]: info: command: 'crm_ticket -t geo-ticket -S expires -v 1408975738' was executed

Site 1:
Aug 25 10:07:58 bb5Atas1 booth-site: [7826]: info: command: 'crm_ticket -t geo-ticket -S owner -v 2' was executed
Aug 25 10:07:58 bb5Atas1 booth-site: [7826]: info: command: 'crm_ticket -t geo-ticket -S expires -v 1408975738' was executed

3 - Site 2 decides that the ticket has expired (at the  expiry time set in step 1)
Aug 25 10:08:10 bb5Btas0 booth-site: [27782]: debug: lease expires ...

4 - At 10:08:58, both site 1 and the arbitrator expire the lease and pick a new master.

I presume that there was some missed communication between site 2 and the rest of the geo-cluster. There is nothing in the logs to help debug this, though. Any hints on debugging this?

BTW: we only ever see this on a site 2 – never a site 1. This is consistent across several labs. Is there a bias towards site 1?

Thanks in advance,

Rob



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