Re: Add ps display while waiting for wal in read_local_xlog_page_guts

Hi,

On 4/13/23 12:43 AM, sirisha chamarthi wrote:
> Hi,
> 
> pg_create_logical_replication_slot can take longer than usual on a standby when there is no activity on the primary.
Wedon't have enough information in the pg_stat_activity or process title to debug why this is taking so long. Attached
asmall patch to update the process title while waiting for the wal in read_local_xlog_page_guts. Any thoughts on
introducinga new wait event too?
 
> 
> For example, in my setup, slot creation took 8 minutes 13 seconds. It only succeeded after I ran select
txid_current()on primary.
 

FWIW, this behavior has been mentioned in 0fdab27ad6 and a new function (pg_log_standby_snapshot()) has been
created/documentedto accelerate the slot creation on the standby.
 

Regards,

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