Re: Synchronizing slots from primary to standby

Hi,

On 12/1/23 4:19 AM, shveta malik wrote:
> On Thu, Nov 30, 2023 at 5:37 PM Ajin Cherian <itsajin(at)gmail(dot)com> wrote:
>>
>>
>> 1. In my opinion, the second message "aborting the wait...moving to
>> the next slot" does not hold much value. There might not even be a
>> "next slot", there might be just one slot. I think the first LOG is
>> enough to indicate that the sync-slot is waiting as it repeats this
>> log till the slot catches up. I know these messages hold great value
>> for debugging but in production, "waiting..", "aborting the wait.."
>> might not be as helpful, maybe change it to debug?
>>
>> 2023-11-30 05:13:49.811 EST [6115] LOG: waiting for remote slot
>> "sub1" LSN (0/3047A90) and catalog xmin (745) to pass local slot LSN
>> (0/3047AC8) and catalog xmin (745)
>> 2023-11-30 05:13:57.909 EST [6115] LOG: aborting the wait for remote
>> slot "sub1" and moving to the next slot, will attempt creating it
>> again
>> 2023-11-30 05:14:07.921 EST [6115] LOG: waiting for remote slot
>> "sub1" LSN (0/3047A90) and catalog xmin (745) to pass local slot LSN
>> (0/3047AC8) and catalog xmin (745)
>>
>
> Sure, the message can be trimmed down. But I am not very sure if we
> should convert it to DEBUG. It might be useful to know what exactly is
> happening with this slot through the log file.Curious to know what
> others think here?
>

I think LOG is fine for the "waiting" one but I'd be tempted to put part of the
message in errdetail().

I think we could get rid of the "aborting" message (or move it to DEBUG). I mean
if one does not see the "newly locally created slot" message then I think it's
enough to guess the wait has been aborted or that it is still waiting.

But that's probably just a matter of taste.

Regards,

--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com