ok i have a small laptop with an even smaller vm :)
pgbench -i s 3
pgbench -c 20 -j 5 -T 900 -M prepared
select wait_event_type, wait_event from pg_stat_activity;
wait_event_type | wait_event
-----------------+---------------------
Activity | LogicalLauncherMain
Activity | AutoVacuumMain
LWLock | WALWrite
Lock | transactionid
Lock | tuple
LWLock | WALWrite
Lock | transactionid
Lock | transactionid
Lock | tuple
Lock | transactionid
Lock | transactionid
Lock | transactionid
Lock | tuple
IO | WALSync
Lock | transactionid
|
Activity | BgWriterHibernate
Activity | CheckpointerMain
LWLock | WALWrite
i then destroyed the slow WAL db
rm -rf data
and built a new one without additional latency to WALdir.
initdb -D data
pg_ctl -D data start
pgbench -i -s 3
pgbench -c 20 -j 5 -T 900 -M prepared
i see similar output as above
but no
WALWriteLock
old thread, just for reference. do not read into anything :)
Thanks,
Vijay
On Fri, 30 Apr 2021 at 00:22, Laurenz Albe <laurenz.albe@xxxxxxxxxxx> wrote:
On Fri, 2021-04-30 at 00:13 +0530, Vijaykumar Jain wrote:
> I tried the below, but i could not simulate WALWriteLock waits.
>
> create table foo(id int)
>
> for i in {1..10}; do psql -c "begin transaction; insert into foo select 1 from generate_series(1, 1000); commit;" & done
Perhaps you should do simple inserts of one row and run that script
with a pgbench and lots of clients.
Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com
