On Wed, Aug 17, 2022 at 2:45 AM Nathan Bossart <nathandboss...@gmail.com> wrote: > > On Wed, Aug 10, 2022 at 11:00:20AM -0400, Robert Haas wrote: > > Maybe the checkpointer is a better candidate, but somehow I feel that > > we can't consider this sort of thing separate from the existing > > progress reporting that checkpointer already does. Perhaps we need to > > think of changing or improving that in some way rather than adding > > something wholly new alongside the existing system. > > I agree that the checkpointer has a good chance of being a better > candidate. Are you thinking of integrating this into log_checkpoints > somehow? Perhaps this parameter could optionally accept an interval for > logging the progress of ongoing checkpoints.
Certainly the checkpointer is an immediate candidate. For instance, I can think of using ereport_progress() in CheckPointSnapBuild() for snapshot files processing, CheckPointLogicalRewriteHeap() for mapping files processing, BufferSync() for checkpointing dirty buffers (?), ProcessSyncRequests() for processing fsync() requests, RemoveOldXlogFiles(), RemoveNonParentXlogFiles()(?). I personally have seen cases where some of these checkpoint operations take a lot of time in production environments and a better observability would help a lot. However, I'm not sure if turning log_checkpoints to an integer type to use for checkpoint progress reporting is a good idea here. As I explained upthread [1], I'd vote for a single GUC at the entire server level. If the users/customers request per-process or per-operation progress report GUCs, we can then consider it. Thoughts? [1] https://www.postgresql.org/message-id/CALj2ACUJA73nCK_Li7v4_OOkRqwQBX14Fx2ALb7GDRwUTNGK-Q%40mail.gmail.com -- Bharath Rupireddy RDS Open Source Databases: https://aws.amazon.com/rds/postgresql/
