Add a new wait state and use it when sending data in the apply worker.

Amit Kapila · Amit Kapila · commit fce003cfde21 · 2023-02-16T07:46:31.000+05:30
d9d7fe6 made use of an existing wait event when sending data from the apply worker, but we should have invented a new wait event since this is a new place to wait. This patch corrects the mistake by using a new wait event "LogicalApplySendData". Author: Hou Zhijie Reviewed-by: Peter Smith Discussion: https://postgr.es/m/CA+TgmobWzbr9H3yN3dLVckviEZKemPwd+XyCFKEgyZQZhgP66Q@mail.gmail.com
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
@@ -1740,6 +1740,11 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       <entry>Waiting for other Parallel Hash participants to finish inserting
        tuples into new buckets.</entry>
      </row>
+     <row>
+      <entry><literal>LogicalApplySendData</literal></entry>
+      <entry>Waiting for a logical replication leader apply process to send
+       data to a parallel apply process.</entry>
+     </row>
      <row>
       <entry><literal>LogicalParallelApplyStateChange</literal></entry>
       <entry>Waiting for a logical replication parallel apply process to change
diff --git a/src/backend/replication/logical/applyparallelworker.c b/src/backend/replication/logical/applyparallelworker.c
@@ -1181,7 +1181,8 @@ pa_send_data(ParallelApplyWorkerInfo *winfo, Size nbytes, const void *data)
 		/* Wait before retrying. */
 		rc = WaitLatch(MyLatch,
 					   WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
-					   SHM_SEND_RETRY_INTERVAL_MS, WAIT_EVENT_MQ_SEND);
+					   SHM_SEND_RETRY_INTERVAL_MS,
+					   WAIT_EVENT_LOGICAL_APPLY_SEND_DATA);
 
 		if (rc & WL_LATCH_SET)
 		{
diff --git a/src/backend/utils/activity/wait_event.c b/src/backend/utils/activity/wait_event.c
@@ -391,6 +391,9 @@ pgstat_get_wait_ipc(WaitEventIPC w)
 		case WAIT_EVENT_HASH_GROW_BUCKETS_REINSERT:
 			event_name = "HashGrowBucketsReinsert";
 			break;
+		case WAIT_EVENT_LOGICAL_APPLY_SEND_DATA:
+			event_name = "LogicalApplySendData";
+			break;
 		case WAIT_EVENT_LOGICAL_PARALLEL_APPLY_STATE_CHANGE:
 			event_name = "LogicalParallelApplyStateChange";
 			break;
diff --git a/src/include/utils/wait_event.h b/src/include/utils/wait_event.h
@@ -106,6 +106,7 @@ typedef enum
 	WAIT_EVENT_HASH_GROW_BUCKETS_ALLOCATE,
 	WAIT_EVENT_HASH_GROW_BUCKETS_ELECT,
 	WAIT_EVENT_HASH_GROW_BUCKETS_REINSERT,
+	WAIT_EVENT_LOGICAL_APPLY_SEND_DATA,
 	WAIT_EVENT_LOGICAL_PARALLEL_APPLY_STATE_CHANGE,
 	WAIT_EVENT_LOGICAL_SYNC_DATA,
 	WAIT_EVENT_LOGICAL_SYNC_STATE_CHANGE,

Original file line number	Diff line number	Diff line change
`@@ -1181,7 +1181,8 @@ pa_send_data(ParallelApplyWorkerInfo winfo, Size nbytes, const void data)`
`1181`	`1181`	`/* Wait before retrying. */`
`1182`	`1182`	`rc = WaitLatch(MyLatch,`
`1183`	`1183`	`WL_LATCH_SET \| WL_TIMEOUT \| WL_EXIT_ON_PM_DEATH,`
`1184`		`- SHM_SEND_RETRY_INTERVAL_MS, WAIT_EVENT_MQ_SEND);`
	`1184`	`+ SHM_SEND_RETRY_INTERVAL_MS,`
	`1185`	`+ WAIT_EVENT_LOGICAL_APPLY_SEND_DATA);`
`1185`	`1186`
`1186`	`1187`	`if (rc & WL_LATCH_SET)`
`1187`	`1188`	`{`