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* Pg/CyberCluster test results
@ 2008-08-22 13:33 CG <cgg007@yahoo.com>
0 siblings, 2 replies; 5+ messages in thread
From: CG @ 2008-08-22 13:33 UTC (permalink / raw)
To: pgsql-admin
I've been testing Cybercluster (which is a modified PgCluster) ... I have two back-end databases, one load balancer, and one replicator. I've been testing failover and rebuilding a degraded cluster, and I'm finidng that it is REALLY easy for the two back-ends to get out of sync with each other. This is very disturbing. I was wondering if anyone has experience with solving this problem.
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Pg/CyberCluster test results
@ 2008-08-22 13:52 RW <postgres@tauceti.net>
parent: CG <cgg007@yahoo.com>
1 sibling, 2 replies; 5+ messages in thread
From: RW @ 2008-08-22 13:52 UTC (permalink / raw)
To: CG <cgg007@yahoo.com>; +Cc: pgsql-admin
I hoped that it would be easier to get the nodes back in sync
but it seems that all Postgres Multi-Master solutions are not
reliable at the moment. I've planed to test CyberCluster
this weekend but I already suspected that this rsync solutions
have some shortcomings. Sniff...
It seems that we have to wait for PGCluster-II which isn't a
"shared nothing" solution. Instead all files are on a shared
medium like SAN or iSCSI and all instances uses this medium
(similar to Oracle).
Robert
CG wrote:
> I've been testing Cybercluster (which is a modified PgCluster) ... I have two back-end databases, one load balancer, and one replicator. I've been testing failover and rebuilding a degraded cluster, and I'm finidng that it is REALLY easy for the two back-ends to get out of sync with each other. This is very disturbing. I was wondering if anyone has experience with solving this problem.
>
>
>
>
>
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Pg/CyberCluster test results
@ 2008-08-22 14:06 RW <postgres@tauceti.net>
parent: RW <postgres@tauceti.net>
1 sibling, 0 replies; 5+ messages in thread
From: RW @ 2008-08-22 14:06 UTC (permalink / raw)
To: pgsql-admin
Maybe some people haven't read this site here:
http://www.postgresqldocs.org/wiki/Replication,_Clustering,_and_Connection_Pooling
It gives a nice overview. Another interesting project which isn't
production ready yet is Postgres-R (http://www.postgres-r.org/)
Robert
RW wrote:
> I hoped that it would be easier to get the nodes back in sync
> but it seems that all Postgres Multi-Master solutions are not
> reliable at the moment. I've planed to test CyberCluster
> this weekend but I already suspected that this rsync solutions
> have some shortcomings. Sniff...
>
> It seems that we have to wait for PGCluster-II which isn't a
> "shared nothing" solution. Instead all files are on a shared
> medium like SAN or iSCSI and all instances uses this medium
> (similar to Oracle).
>
> Robert
>
> CG wrote:
>> I've been testing Cybercluster (which is a modified PgCluster) ... I
>> have two back-end databases, one load balancer, and one replicator.
>> I've been testing failover and rebuilding a degraded cluster, and I'm
>> finidng that it is REALLY easy for the two back-ends to get out of
>> sync with each other. This is very disturbing. I was wondering if
>> anyone has experience with solving this problem.
>>
>>
>>
>>
>
>
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Pg/CyberCluster test results
@ 2008-08-22 15:15 Andrew Sullivan <ajs@commandprompt.com>
parent: RW <postgres@tauceti.net>
1 sibling, 0 replies; 5+ messages in thread
From: Andrew Sullivan @ 2008-08-22 15:15 UTC (permalink / raw)
To: pgsql-admin
On Fri, Aug 22, 2008 at 03:52:39PM +0200, RW wrote:
> It seems that we have to wait for PGCluster-II which isn't a
> "shared nothing" solution. Instead all files are on a shared
> medium like SAN or iSCSI and all instances uses this medium
> (similar to Oracle).
That's not shared-nothing, it's shared-storage.
A
--
Andrew Sullivan
ajs@commandprompt.com
+1 503 667 4564 x104
http://www.commandprompt.com/
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Pg/CyberCluster test results
@ 2008-08-22 15:17 Andrew Sullivan <ajs@commandprompt.com>
parent: CG <cgg007@yahoo.com>
1 sibling, 0 replies; 5+ messages in thread
From: Andrew Sullivan @ 2008-08-22 15:17 UTC (permalink / raw)
To: pgsql-admin
On Fri, Aug 22, 2008 at 06:33:50AM -0700, CG wrote:
> cluster, and I'm finidng that it is REALLY easy for the two
> back-ends to get out of sync with each other.
When I investigated that product, I came to the conclusion that it's
in the family of replication by query-dispatch. Everything in that
family has this problem, and it's a fundamental limitation of the
approach.
A
--
Andrew Sullivan
ajs@commandprompt.com
+1 503 667 4564 x104
http://www.commandprompt.com/
^ permalink raw reply [nested|flat] 5+ messages in thread
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2008-08-22 13:33 Pg/CyberCluster test results CG <cgg007@yahoo.com>
2008-08-22 13:52 ` RW <postgres@tauceti.net>
2008-08-22 14:06 ` RW <postgres@tauceti.net>
2008-08-22 15:15 ` Andrew Sullivan <ajs@commandprompt.com>
2008-08-22 15:17 ` Andrew Sullivan <ajs@commandprompt.com>
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