digoal
2023-07-13
PostgreSQL , PolarDB , parallel , progress
增加并行执行worker进程的进度通知消息, 以掌握parallel worker进程的执行进度.
未来也许会支持动态并行调度优化. 类似现在PorlarDB做的epq.
https://apsaradb.github.io/PolarDB-for-PostgreSQL/zh/features/v11/htap/adaptive-scan.html
Add new parallel message type to progress reporting.
author Masahiko Sawada <msawada@postgresql.org>
Tue, 11 Jul 2023 03:33:54 +0000 (12:33 +0900)
committer Masahiko Sawada <msawada@postgresql.org>
Tue, 11 Jul 2023 03:33:54 +0000 (12:33 +0900)
commit f1889729dd3ab0352dc0ccc2ffcc1b1901f8e39f
tree 6c82b614a2f73a9f5ab2a83c32da8cdf832d1079 tree
parent 26dd0284b98f6bf730dc1f7f7e1f917525d71eda commit | diff
Add new parallel message type to progress reporting.
This commit adds a new type of parallel message 'P' to allow a
parallel worker to poke at a leader to update the progress.
Currently it supports only incremental progress reporting but it's
possible to allow for supporting of other backend progress APIs in the
future.
There are no users of this new message type as of this commit. That
will follow in future commits.
Idea from Andres Freund.
Author: Sami Imseih
Reviewed by: Michael Paquier, Masahiko Sawada
Discussion: https://www.postgresql.org/message-id/flat/5478DFCD-2333-401A-B2F0-0D186AB09228@amazon.com
+/*-----------
+ * pgstat_progress_parallel_incr_param() -
+ *
+ * A variant of pgstat_progress_incr_param to allow a worker to poke at
+ * a leader to do an incremental progress update.
+ *-----------
+ */
+void
+pgstat_progress_parallel_incr_param(int index, int64 incr)
+{
+ /*
+ * Parallel workers notify a leader through a 'P' protocol message to
+ * update progress, passing the progress index and incremented value.
+ * Leaders can just call pgstat_progress_incr_param directly.
+ */
+ if (IsParallelWorker())
+ {
+ static StringInfoData progress_message;
+
+ initStringInfo(&progress_message);
+
+ pq_beginmessage(&progress_message, 'P');
+ pq_sendint32(&progress_message, index);
+ pq_sendint64(&progress_message, incr);
+ pq_endmessage(&progress_message);
+ }
+ else
+ pgstat_progress_incr_param(index, incr);
+}
