[Pgcluster-general] Last chance to get everything working

[Christian Dannemann]

Hi Atsushi,

You might remember that I was in contact back then when we went live and 
you gave me quite a lot of support. The main problem was that servers 
kept dropping out of the cluster, recovery didn't work, and sometimes 
the whole cluster just hung. I just felt that I couldn't continue to run 
the software in a production enviroment (an hour of outtime is a 50k 
loss) and I felt that we never got to the root of the problem. You did 
make some fixes, but it never resolved our issues.

I admit that our set-up maybe a bit too much high-performance - we have 
to deal with several million updates per day and maybe that's just too much.

I think the main problem was having 4 servers in the cluster. Gut 
feeling tells me that there were timeout issues with updates - but 
that's just a guess.

The environment doesn't exist any more so I'm afraid I can't do any 
further testing on this.

Best Regards,

Christian

a.mitani at sra-europe.com wrote:
> Hi Christian,
>
> It is surprise for me that the cluster hanged whithout any reason.
> I have to correct it.
> Would you let me know the details, if you don't mind.
>
> Regards,
> ---------------------------
> At.Mitani
>
>   
>> we had pgcluster running in production for about 3 weeks and then
>> stopped as we had huge problems with the cluster just hanging without
>> any reason - as this was driving a web site with a huge turnover, we
>> found the performance to be unacceptable and are now back to using
>> postgresql without replication.
>>
>> Regards,
>>
>> Christian
>>
>>
>> John Gardner wrote:
>>     
>>> I've been working with pgCluster for the last four months now, I'm at
>>> the stage where we need to install it in a production environment, but I
>>> must say that I'm still apprehensive about a few things, some things
>>> certainly don't work in my environment.  I have chatted with Rick Vernam
>>> about a few of these problems, and although we seem to have the same
>>> configuration, his works and mine doesn't.
>>>
>>> My configuration is this:
>>>
>>>     DB 1               DB 2                                DB 3
>>> +--------------+   +--------------+                  +--------------+
>>> |   cluster_1  |   |   cluster_2  |       VPN        |   cluster_3  |
>>> |   rep_1      |---|   rep_2      |------------------|   rep_3      |
>>> |   lb_1       |   |   lb_2       |                  |              |
>>> +--------------+   +--------------+                  +--------------+
>>>        |                   |
>>>        |                   |
>>> +--------------+   +--------------+
>>> |   Apache     |   |   Apache     |
>>> |   mod_jk     |   |   mod_jk     |
>>> |   Tomcat     |---|   Tomcat     |
>>> +--------------+   +--------------+
>>>      APP 1APP 2
>>>
>>> My problems are:
>>>
>>> - Replication works between all of the nodes under normal circumstances.
>>> - Multiple replicator failover doesn't work.
>>> - Occasionally when bringing a DB Cluster node back up in recovery mode,
>>> access to the remaining DB clusters locks and I can't access anything
>>> either via the load balancer or directly.
>>> - Does <Response_Mode> have any use at all? One of the reasons for going
>>> down the pgCluster route was the 'normal' operation, but I've just read
>>> a post on the mailing list from Atsushi saying that normal operation
>>> doesn't work and should be removed.
>>> - What is the difference of setting <Use_Replication_Log> to yes or no?
>>>
>>> We really, have to make a decision this week, whether we stick with
>>> pgCluster or go via another route.  I've stuck with pgCluster for this
>>> long because I was convinced that the reason it was not performing as I
>>> had expected was due to configuration errors, but now I'm not so sure...
>>> If anyone can give me any help I would be extremely grateful!
>>>
>>> Thanks in advance
>>>
>>> John
>>> _______________________________________________
>>> Pgcluster-general mailing list
>>> Pgcluster-general at pgfoundry.org
>>> http://pgfoundry.org/mailman/listinfo/pgcluster-general
>>>
>>>       
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>>     
>
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