Re: Hot Standby (v9d)

Simon Riggs wrote:
> On Sat, 2009-01-24 at 11:20 +0000, Simon Riggs wrote:
>   
>> On Sat, 2009-01-24 at 17:24 +1300, Mark Kirkwood wrote:
>>
>>     
>>>> version 9g - please use this for testing now
>>>>         
>>> I'm doing some test runs with this now. I notice an old flatfiles 
>>> related bug has reappeared:
>>>       
>> I'm seeing an off-by-one error on xmax, in some cases. That then causes
>> the flat file update to not pick up correct info, even though it
>> executed in other ways as intended. If you run two create databases and
>> then test only the first, it appears to have worked as intended.
>>
>> These bugs are result of recent refactoring and it will take a few days
>> to shake some of them out. We've had more than 20 already so we're
>> beating them back, but we're not done yet. 
>>     
>
> I was at a loss to explain how this could have slipped through our
> tests. It appears that the error was corrected following each checkpoint
> as a result of ProcArrayUpdateRunningXacts(). Our tests were performed
> after a short delay, which typically would be greater than the
> deliberately short setting of checkpoint_timeout/archive_timeout and so
> by the time we looked the error was gone and masked the problem. We're
> setting checkpoint_timeout to 30 mins now to avoid the delay...
>
>   
That makes sense - I had archive_timeout set at 5 minutes, and I would 
have checked before 5 minutes were up.

Cheers

Mark