On 2024/10/17 22:15, Seino Yuki wrote:
Considering both points, I’m leaning toward adding a new GUC parameter
to control whether detailed logs should be generated for failed
NOWAIT locks (and possibly for those canceled by lock_timeout).
Alternatively, if adding a new GUC is not ideal, we could extend
log_lock_waits to accept a new value like 'error,' which would trigger
detailed logging when a lock wait fails due to NOWAIT, lock_timeout,
or cancellation.
That's a good idea. I'll try that.
Sorry, I misunderstood.
The pid and xid are output during deadlock_timeout.
LOG: process 1443346 still waiting for ShareLock on transaction 770 after
1000.096 ms
DETAIL: Process holding the lock: 1443241. Wait queue: 1443346.
This log output is not triggered by lock_timeout or cancellation.
Yes, these log messages with PID or XID are generated by log_lock_waits, not
lock_timeout.
Therefore, it is difficult to support lock_timeout and cancellation.
I am thinking of supporting only NOWAIT. What do you think?
I'm not sure why it's challenging to provide detailed log messages for lock
waits canceled
by lock_timeout or user cancellation, while it's considered feasible for the
NOWAIT case.
However, I think it's reasonable to implement this feature step by step. We can
start
by adding support for the NOWAIT case and consider extending it to handle
lock_timeout and
cancellation scenarios later if possible.
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
