Re: PostgreSQL 10.5 : Strange pg_wal fill-up, solved with theshutdown checkpoint

On 6/11/18 4:58 μ.μ., Tom Lane wrote:
> Achilleas Mantzios <achill@matrix.gatewaynet.com> writes:
>> Remember : postgresql checkpointer decided to remove 5000+ files before shutdown. If any conditions were keeping
thosefiles 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