Re: Perform streaming logical transactions by background workers and parallel apply

Peter Smith <smithpb2250@gmail.com>

From: Peter Smith <smithpb2250@gmail.com>
To: "shiy.fnst@fujitsu.com" <shiy.fnst@fujitsu.com>
Cc: "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, Amit Kapila <amit.kapila16@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-05-19T06:22:08Z
Lists: pgsql-hackers
Here are my review comments for v6-0002.

======

1. src/test/subscription/t/015_stream.pl

+################################
+# Test using streaming mode 'on'
+################################
 $node_subscriber->safe_psql('postgres',
  "CREATE SUBSCRIPTION tap_sub CONNECTION '$publisher_connstr
application_name=$appname' PUBLICATION tap_pub WITH (streaming = on)"
 );
-
 $node_publisher->wait_for_catchup($appname);
-
 # Also wait for initial table sync to finish
 my $synced_query =
   "SELECT count(1) = 0 FROM pg_subscription_rel WHERE srsubstate NOT
IN ('r', 's');";
 $node_subscriber->poll_query_until('postgres', $synced_query)
   or die "Timed out while waiting for subscriber to synchronize data";
-
 my $result =
   $node_subscriber->safe_psql('postgres',
  "SELECT count(*), count(c), count(d = 999) FROM test_tab");
 is($result, qq(2|2|2), 'check initial data was copied to subscriber');

1a.
Several whitespace lines became removed by the patch. IMO it was
better (e.g. less squishy) how it looked originally.

1b.
Maybe some more blank lines should be added to the 'apply' test part
too, to match 1a.

~~~

2. src/test/subscription/t/015_stream.pl

+$node_publisher->poll_query_until('postgres',
+ "SELECT pid != $oldpid FROM pg_stat_replication WHERE
application_name = '$appname' AND state = 'streaming';"
+) or die "Timed out while waiting for apply to restart after changing
PUBLICATION";

Should that say "... after changing SUBSCRIPTION"?

~~~

3. src/test/subscription/t/016_stream_subxact.pl

+$node_publisher->poll_query_until('postgres',
+ "SELECT pid != $oldpid FROM pg_stat_replication WHERE
application_name = '$appname' AND state = 'streaming';"
+) or die "Timed out while waiting for apply to restart after changing
PUBLICATION";
+

Should that say "... after changing SUBSCRIPTION"?

~~~

4. src/test/subscription/t/017_stream_ddl.pl

+$node_publisher->poll_query_until('postgres',
+ "SELECT pid != $oldpid FROM pg_stat_replication WHERE
application_name = '$appname' AND state = 'streaming';"
+) or die "Timed out while waiting for apply to restart after changing
PUBLICATION";
+

Should that say "... after changing SUBSCRIPTION"?

~~~

5. .../t/018_stream_subxact_abort.pl

+$node_publisher->poll_query_until('postgres',
+ "SELECT pid != $oldpid FROM pg_stat_replication WHERE
application_name = '$appname' AND state = 'streaming';"
+) or die "Timed out while waiting for apply to restart after changing
PUBLICATION";

Should that say "... after changing SUBSCRIPTION" ?

~~~

6. .../t/019_stream_subxact_ddl_abort.pl

+$node_publisher->poll_query_until('postgres',
+ "SELECT pid != $oldpid FROM pg_stat_replication WHERE
application_name = '$appname' AND state = 'streaming';"
+) or die "Timed out while waiting for apply to restart after changing
PUBLICATION";
+

Should that say "... after changing SUBSCRIPTION"?

~~~

7. .../subscription/t/023_twophase_stream.pl

###############################
# Check initial data was copied to subscriber
###############################

Perhaps the above comment now looks a bit out-of-place with the extra #####.

Looks better now as just:
# Check initial data was copied to the subscriber

~~~

8. .../subscription/t/023_twophase_stream.pl

+$node_publisher->poll_query_until('postgres',
+ "SELECT pid != $oldpid FROM pg_stat_replication WHERE
application_name = '$appname' AND state = 'streaming';"
+) or die "Timed out while waiting for apply to restart after changing
PUBLICATION";

Should that say "... after changing SUBSCRIPTION"?

------
Kind Regards,
Peter Smith.
Fujitsu Australia



Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Fix invalid memory access during the shutdown of the parallel apply worker.

  2. Fix assertion failure in apply worker.

  3. Use elog to report unexpected action in handle_streamed_transaction().

  4. Use appropriate wait event when sending data in the apply worker.

  5. Allow the logical_replication_mode to be used on the subscriber.

  6. Rename GUC logical_decoding_mode to logical_replication_mode.

  7. Display the leader apply worker's PID for parallel apply workers.

  8. Improve the code to decide and process the apply action.

  9. Document the newly added wait events added by commit 216a784829.

  10. Perform apply of large transactions by parallel workers.

  11. Wake up a subscription's replication worker processes after DDL.

  12. Add copyright notices to meson files

  13. Better document logical replication parameters

  14. Add a common function to generate the origin name.

  15. Harmonize parameter names in storage and AM code.

  16. Avoid using list_length() to test for empty list.

  17. Improve two comments related to a boolean DefElem's value

  18. Fix partition table's REPLICA IDENTITY checking on the subscriber.

  19. Fix data inconsistency between publisher and subscriber.

  20. Fix cache look-up failures while applying changes in logical replication.