On 6/11/18 4:58 μ.μ., Tom Lane wrote:
Achilleas Mantzios <achill@xxxxxxxxxxxxxxxxxxxxx> writes:
Remember : postgresql checkpointer decided to remove 5000+ files before shutdown. If any conditions were keeping those files afloat should also hold at this point, right.
The question is why didn't Postgresql removed them earlier.
WAL files get removed/recycled after completion of a checkpoint. So
apparently, checkpoints were not finishing during normal operation,
but the shutdown checkpoint managed to terminate normally. That
eliminates a lot of the usual theories about why checkpoints might
not be succeeding (like a dirty buffer that always fails to be
written, say as a result of broken permissions on its file).
The only theory that comes to mind is that the checkpointer process
was stuck somehow, but just "soft" stuck, in a way that allowed the
postmaster's time-to-shut-down-please signal to unstick it. No,
I have no idea how that could happen exactly. If it happens again,
it'd be really interesting to attach to the checkpointer with a
debugger and collect a stack trace.
Thank you Tom. Should I also re-run configure --enable-debug && make clean install ? Initially PostgreSQL was built without --enable-debug, so currently it does not show source code line numbers in
gdb bt .
regards, tom lane
--
Achilleas Mantzios
IT DEV Lead
IT DEPT
Dynacom Tankers Mgmt
