Dear hackers, Hi, I did a performance testing for v16 patch set. Results show that patches significantly improves the performance in most cases.
# Method Following tests were done 10 times per condition, and compared by median. do_one_test.sh was used for the testing. 1. Create tables on publisher 2. Insert initial data on publisher 3. Create tables on subscriber 4. Create a replication slot (mysub_slot) on publisher 5. Create a publication on publisher 6. Create tables on subscriber --- timer on --- 7. Create subscription with pre-existing replication slot (mysub_slot) 8. Wait until all srsubstate in pg_subscription_rel becomes 'r' --- timer off --- # Tested sources I used three types of sources * HEAD (f863d82) * HEAD + 0001 + 0002 * HEAD + 0001 + 0002 + 0003 # Tested conditions Following parameters were changed during the measurement. ### table size * empty * around 10kB ### number of tables * 10 * 100 * 1000 * 2000 ### max_sync_workers_per_subscription * 2 * 4 * 8 * 16 ## Results Please see the attached image file. Each cell shows the improvement percentage of measurement comapred with HEAD, HEAD + 0001 + 0002, and HEAD + 0001 + 0002 + 0003. According to the measurement, we can say following things: * In any cases the performance was improved from the HEAD. * The improvement became more significantly if number of synced tables were increased. * 0003 basically improved performance from first two patches * Increasing workers could sometimes lead to lesser performance due to contention. This was occurred when the number of tables were small. Moreover, this was not only happen by patchset - it happened even if we used HEAD. Detailed analysis will be done later. Mored deital, please see the excel file. It contains all the results of measurement. ## Detailed configuration * Powerful machine was used: - Number of CPU: 120 - Memory: 755 GB * Both publisher and subscriber were on the same machine. * Following GUC settings were used for both pub/sub: ``` wal_level = logical shared_buffers = 40GB max_worker_processes = 32 max_parallel_maintenance_workers = 24 max_parallel_workers = 32 synchronous_commit = off checkpoint_timeout = 1d max_wal_size = 24GB min_wal_size = 15GB autovacuum = off max_wal_senders = 200 max_replication_slots = 200 ``` Best Regards, Hayato Kuroda FUJITSU LIMITED
perftest_result.xlsx
Description: perftest_result.xlsx
do_one_test.sh
Description: do_one_test.sh
