On Tue, Mar 29, 2022 5:15 PM Hou, Zhijie/侯 志杰 <[email protected]> wrote:
>
> Thanks for the comment.
> Attach the new version patch with this change.
>
Hi,
I did a performance test for this patch to see if it affects performance when
publishing empty transactions, based on the v32 patch.
In this test, I use synchronous logical replication, and publish a table with no
operations on it. The test uses pgbench, each run takes 15 minutes, and I take
median of 3 runs. Drop and recreate db after each run.
The results are as follows, and attach the bar chart. The details of the test is
also attached.
TPS - publishing empty transactions (scale factor 1)
--------------------------------------------------------------------
4 threads 8 threads 16 threads
HEAD 4818.2837 4353.6243 3888.5995
patched 5111.2936 4555.1629 4024.4286
TPS - publishing empty transactions (scale factor 100)
--------------------------------------------------------------------
4 threads 8 threads 16 threads
HEAD 9066.6465 16118.0453 21485.1207
patched 9357.3361 16638.6409 24503.6829
There is an improvement of more than 3% after applying this patch, and in the
best case, it improves by 14%, which looks good to me.
Regards,
Shi yu
Some parameters specified in postgresql.conf
=====================================================
shared_buffers = 8GB
checkpoint_timeout = 30min
max_wal_size = 20GB
min_wal_size = 10GB
autovacuum = off
Steps
=====================================================
-- in publisher
-- using scale factor 100
pgbench -i postgres -p 5432 -s 100
-- using default scale factor, 1
pgbench -i postgres -p 5432
-- create table in publisher and subscriber
CREATE TABLE tbl_empty (a int);
-- create publication
create publication pub for table tbl_empty;
-- create subscription
CREATE SUBSCRIPTION sub CONNECTION 'host=localhost port=5432 dbname=postgres'
PUBLICATION pub;"
Then set synchronous replication and restart publisher server.
Run pgbench and record the TPS.
pgbench -b tpcb-like -c 4 -j 4 -T 900 -n postgres
About the test machine
=====================================================
The processor spec of the test machine is Intel® Xeon® Silver 4210 CPU
@2.20GHz with 10 cores/20 threads/2 sockets.
