On Wed, 2011-06-15 at 19:31 +0900, Tatsuo Ishii wrote: > > On Fri, 2011-06-10 at 20:20 +0200, Guillaume Lelarge wrote: > >> On Thu, 2011-05-26 at 09:06 +0200, Guillaume Lelarge wrote: > >> > Le 05/26/2011 12:57 AM, Tatsuo Ishii a écrit : > >> > [...] > >> > >> When I do the pcp_detach_node, I have this: > >> > >> > >> > >> 2011-05-25 20:24:12 LOG: pid 31861: notice_backend_error: 0 fail > >> > >> over > >> > >> request from pid 31861 > >> > >> 2011-05-25 20:24:12 LOG: pid 31828: starting degeneration. shutdown > >> > >> host localhost(5432) > >> > >> 2011-05-25 20:24:12 ERROR: pid 31828: failover_handler: no valid DB > >> > >> node > >> > >> found > >> > >> 2011-05-25 20:24:12 LOG: pid 31828: failover done. shutdown host > >> > >> localhost(5432) > >> > >> > >> > >> Which seems fine to me. Then I do the pcp_attach_node, and I got this: > >> > >> > >> > >> 2011-05-25 20:25:23 LOG: pid 31861: send_failback_request: fail > >> > >> back 0 > >> > >> th node request from pid 31861 > >> > >> 2011-05-25 20:25:23 ERROR: pid 31861: send_failback_request: node 0 is > >> > >> alive. > >> > >> > >> > >> I was mistaken on the "node 0 is alive" message. I thought it means > >> > >> that > >> > >> node 0 is NOW up. What it really means is that pgpool thought it was > >> > >> ALREADY alive (hence the ERROR message level on the > >> > >> send_failback_request function). Digging harder on this issue, I > >> > >> finally > >> > >> found that the VALID_BACKEND macro returns true when it should return > >> > >> false. Actually, there is already this comment in > >> > >> get_next_master_node(): > >> > >> > >> > >> /* > >> > >> * Do not use VALID_BACKEND macro in raw mode. > >> > >> * VALID_BACKEND return true only if the argument is master > >> > >> * node id. In other words, standby nodes are false. So need > >> > >> * to check backend status without VALID_BACKEND. > >> > >> */ > >> > >> > >> > >> And I'm actually in raw mode. VALID_BACKEND is used so much it would > >> > >> be > >> > >> really dangerous to change it. So, I'm not sure what we really should > >> > >> do > >> > >> here. I've got a patch that fixes my issue cleanly, not sure it's the > >> > >> best way to do this. See the patch in attachment. > >> > > > >> > > My suggestion is, leave this as it is for 3.0.4. I think we need more > >> > > time to investigate it. Let's continue the work after 3.0.4 released. > >> > > We already have critical issues such as "unnamed statement not found" > >> > > with 3.0.3, and I have personaly sent to users who were troubled by > >> > > this issue the 3.0-STABLE CVS tar ball by their request. If we delay > >> > > the 3.0.4 release, more and more this kind of questions/requests will > >> > > be coming. I don't want to be troubled... > >> > > > >> > > >> > I agree. I have no problem with dealing with this for 3.0.5, or even 3.1. > >> > > >> > >> Now that 3.0.4 is out, maybe it's the right time to work on this. > >> > >> This issue is really a bad one. I had this week a mail from one of our > >> customers, complaining that the online recovery process doesn't work > >> because it thinks the node is still alive. And guess what... it uses the > >> VALID_BACKEND, even if pgpool was working in raw mode. > >> > >> What could we do about this? My patch fixes the previous error, but not > >> this one. I now would be more in favor of a VALID_RAW_BACKEND macro. > >> > > > > No comments on this? meaning I finish my patch and commit it? or meaning > > we don't care about that issue? :) > > Can you please explain why you use raw mode *and* online recovery > together? To be honest I have not thought about such a use case.
Yeah, I tried a few things and I didn't find a way to reproduce that behaviour. I sent an email to my customer to know more about this issue. Anyway, my first patch still applies. The one in the mail sent Wed, 25 May 2011 22:13:17 +0200, on this thread. -- Guillaume http://blog.guillaume.lelarge.info http://www.dalibo.com _______________________________________________ Pgpool-hackers mailing list [email protected] http://pgfoundry.org/mailman/listinfo/pgpool-hackers
