Re: Perform streaming logical transactions by background workers and parallel apply
Amit Kapila <amit.kapila16@gmail.com>
On Thu, Dec 15, 2022 at 8:58 AM houzj.fnst@fujitsu.com
<houzj.fnst@fujitsu.com> wrote:
>
Few minor comments:
=================
1.
+ for (i = list_length(subxactlist) - 1; i >= 0; i--)
+ {
+ TransactionId xid_tmp = lfirst_xid(list_nth_cell(subxactlist, i));
+
+ if (xid_tmp == subxid)
+ {
+ RollbackToSavepoint(spname);
+ CommitTransactionCommand();
+ subxactlist = list_truncate(subxactlist, i + 1);
I find that there is always one element extra in the list after
rollback to savepoint. Don't we need to truncate the list to 'i' as
shown in the diff below?
2.
* Note that If it's an empty sub-transaction then we will not find
* the subxid here.
If in above comment seems to be in wrong case. Anyway, I have slightly
modified it as you can see in the diff below.
$ git diff
diff --git a/src/backend/replication/logical/applyparallelworker.c
b/src/backend/replication/logical/applyparallelworker.c
index 11695c75fa..c809b1fd01 100644
--- a/src/backend/replication/logical/applyparallelworker.c
+++ b/src/backend/replication/logical/applyparallelworker.c
@@ -1516,8 +1516,8 @@ pa_stream_abort(LogicalRepStreamAbortData *abort_data)
* Search the subxactlist, determine the offset tracked for the
* subxact, and truncate the list.
*
- * Note that If it's an empty sub-transaction then we
will not find
- * the subxid here.
+ * Note that for an empty sub-transaction we won't
find the subxid
+ * here.
*/
for (i = list_length(subxactlist) - 1; i >= 0; i--)
{
@@ -1527,7 +1527,7 @@ pa_stream_abort(LogicalRepStreamAbortData *abort_data)
{
RollbackToSavepoint(spname);
CommitTransactionCommand();
- subxactlist = list_truncate(subxactlist, i + 1);
+ subxactlist = list_truncate(subxactlist, i);
break;
}
}
--
With Regards,
Amit Kapila.
Commits
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the thread's linked commits as JSON, with link sources.
API reference →
-
Fix invalid memory access during the shutdown of the parallel apply worker.
- 3d144c6c8602 16.0 landed
-
Fix assertion failure in apply worker.
- de63f8dadee4 16.0 landed
-
Use elog to report unexpected action in handle_streamed_transaction().
- 781ac42d43ab 16.0 landed
-
Use appropriate wait event when sending data in the apply worker.
- d9d7fe68d35e 16.0 landed
-
Allow the logical_replication_mode to be used on the subscriber.
- 9f2213a7c575 16.0 landed
-
Rename GUC logical_decoding_mode to logical_replication_mode.
- 1e8b61735cfb 16.0 landed
-
Display the leader apply worker's PID for parallel apply workers.
- d540a02a724b 16.0 landed
-
Improve the code to decide and process the apply action.
- c981d9145dea 16.0 landed
-
Document the newly added wait events added by commit 216a784829.
- cd06ccd78fcf 16.0 landed
-
Perform apply of large transactions by parallel workers.
- 216a784829c2 16.0 landed
-
Wake up a subscription's replication worker processes after DDL.
- c6e1f62e2cee 16.0 cited
-
Add copyright notices to meson files
- 8284cf5f746f 16.0 cited
-
Better document logical replication parameters
- a8500750ca0a 16.0 cited
-
Add a common function to generate the origin name.
- 776e1c8a5d14 16.0 cited
-
Harmonize parameter names in storage and AM code.
- bfcf1b34805f 16.0 cited
-
Avoid using list_length() to test for empty list.
- efd0c16becbf 16.0 cited
-
Improve two comments related to a boolean DefElem's value
- 8445f5a21d40 16.0 cited
-
Fix partition table's REPLICA IDENTITY checking on the subscriber.
- 26b3455afaa9 15.0 cited
-
Fix data inconsistency between publisher and subscriber.
- b7658c24c7c1 15.0 cited
-
Fix cache look-up failures while applying changes in logical replication.
- 5a97b1325453 15.0 cited