v2-0001-Report-progress-of-REINDEX-operations.patch

From 22c0254b76be05a2235ed84268d189fa6785e844 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Fri, 5 Apr 2019 22:27:14 +0200
Subject: [PATCH v2] Report progress of REINDEX operations

This uses the same infrastructure that the CREATE INDEX progress
reporting uses.
---
 doc/src/sgml/monitoring.sgml         | 52 +++++++++++++++++++++-------
 src/backend/catalog/index.c          | 10 ++++++
 src/backend/catalog/system_views.sql | 11 +++---
 src/backend/commands/indexcmds.c     | 39 ++++++++++++++++++---
 src/include/commands/progress.h      |  3 ++
 src/test/regress/expected/rules.out  | 11 +++---
 6 files changed, 102 insertions(+), 24 deletions(-)

diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index b946e13fdc..4eb43f2de9 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -346,7 +346,7 @@ <title>Dynamic Statistics Views</title>
 
      <row>
       <entry><structname>pg_stat_progress_create_index</structname><indexterm><primary>pg_stat_progress_create_index</primary></indexterm></entry>
-      <entry>One row for each backend running <command>CREATE INDEX</command>, showing
+      <entry>One row for each backend running <command>CREATE INDEX</command> or <command>REINDEX</command>, showing
       current progress.
       See <xref linkend='create-index-progress-reporting'/>.
      </entry>
@@ -3477,7 +3477,7 @@ <title>Progress Reporting</title>
   <title>CREATE INDEX Progress Reporting</title>
 
   <para>
-   Whenever <command>CREATE INDEX</command> is running, the
+   Whenever <command>CREATE INDEX</command> or <command>REINDEX</command> is running, the
    <structname>pg_stat_progress_create_index</structname> view will contain
    one row for each backend that is currently creating indexes.  The tables
    below describe the information that will be reported and provide information
@@ -3516,6 +3516,12 @@ <title><structname>pg_stat_progress_create_index</structname> View</title>
       <entry><type>oid</type></entry>
       <entry>OID of the table on which the index is being created.</entry>
      </row>
+     <row>
+      <entry><structfield>index_relid</structfield></entry>
+      <entry><type>oid</type></entry>
+      <entry>OID of the index being created or reindexed.  During a
+      non-concurrent <command>CREATE INDEX</command>, this is 0.</entry>
+     </row>
      <row>
       <entry><structfield>phase</structfield></entry>
       <entry><type>text</type></entry>
@@ -3605,15 +3611,15 @@ <title>CREATE INDEX phases</title>
      <row>
       <entry><literal>initializing</literal></entry>
       <entry>
-       <command>CREATE INDEX</command> is preparing to create the index.  This
+       <command>CREATE INDEX</command> or <command>REINDEX</command> is preparing to create the index.  This
        phase is expected to be very brief.
       </entry>
      </row>
      <row>
-      <entry><literal>waiting for old snapshots</literal></entry>
+      <entry><literal>waiting for writers before build</literal></entry>
       <entry>
-       <command>CREATE INDEX CONCURRENTLY</command> is waiting for transactions
-       that can potentially see the table to release their snapshots.
+       <command>CREATE INDEX CONCURRENTLY</command> or <command>REINDEX CONCURRENTLY</command> is waiting for transactions
+       with write locks that can potentially see the table to finish.
        This phase is skipped when not in concurrent mode.
        Columns <structname>lockers_total</structname>, <structname>lockers_done</structname>
        and <structname>current_locker_pid</structname> contain the progress 
@@ -3632,10 +3638,10 @@ <title>CREATE INDEX phases</title>
       </entry>
      </row>
      <row>
-      <entry><literal>waiting for writer snapshots</literal></entry>
+      <entry><literal>waiting for writers before validation</literal></entry>
       <entry>
-       <command>CREATE INDEX CONCURRENTLY</command> is waiting for transactions
-       that can potentially write into the table to release their snapshots.
+       <command>CREATE INDEX CONCURRENTLY</command> or <command>REINDEX CONCURRENTLY</command> is waiting for transactions
+       with write locks that can potentially write into the table to finish.
        This phase is skipped when not in concurrent mode.
        Columns <structname>lockers_total</structname>, <structname>lockers_done</structname>
        and <structname>current_locker_pid</structname> contain the progress 
@@ -3670,9 +3676,9 @@ <title>CREATE INDEX phases</title>
       </entry>
      </row>
      <row>
-      <entry><literal>waiting for reader snapshots</literal></entry>
+      <entry><literal>waiting for old snapshots</literal></entry>
       <entry>
-       <command>CREATE INDEX CONCURRENTLY</command> is waiting for transactions
+       <command>CREATE INDEX CONCURRENTLY</command> or <command>REINDEX CONCURRENTLY</command> is waiting for transactions
        that can potentially see the table to release their snapshots.  This
        phase is skipped when not in concurrent mode.
        Columns <structname>lockers_total</structname>, <structname>lockers_done</structname>
@@ -3680,6 +3686,28 @@ <title>CREATE INDEX phases</title>
        information for this phase.
       </entry>
      </row>
+     <row>
+      <entry><literal>waiting for readers before marking dead</literal></entry>
+      <entry>
+       <command>REINDEX CONCURRENTLY</command> is waiting for transactions
+       with read locks on the table to finish, before marking the old index dead.
+       This phase is skipped when not in concurrent mode.
+       Columns <structname>lockers_total</structname>, <structname>lockers_done</structname>
+       and <structname>current_locker_pid</structname> contain the progress 
+       information for this phase.
+      </entry>
+     </row>
+     <row>
+      <entry><literal>waiting for readers before dropping</literal></entry>
+      <entry>
+       <command>REINDEX CONCURRENTLY</command> is waiting for transactions
+       with read locks on the table to finish, before dropping the old index.
+       This phase is skipped when not in concurrent mode.
+       Columns <structname>lockers_total</structname>, <structname>lockers_done</structname>
+       and <structname>current_locker_pid</structname> contain the progress 
+       information for this phase.
+      </entry>
+     </row>
     </tbody>
    </tgroup>
   </table>
@@ -3937,7 +3965,7 @@ <title><structname>pg_stat_progress_cluster</structname> View</title>
     </row>
     <row>
      <entry><structfield>cluster_index_relid</structfield></entry>
-     <entry><type>bigint</type></entry>
+     <entry><type>oid</type></entry>
      <entry>
        If the table is being scanned using an index, this is the OID of the
        index being used; otherwise, it is zero.
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 2ed7fdb021..9b1d546791 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -3286,12 +3286,20 @@ reindex_index(Oid indexId, bool skip_constraint_checks, char persistence,
 	heapId = IndexGetRelation(indexId, false);
 	heapRelation = table_open(heapId, ShareLock);
 
+	pgstat_progress_start_command(PROGRESS_COMMAND_CREATE_INDEX,
+								  heapId);
+	pgstat_progress_update_param(PROGRESS_CREATEIDX_INDEX_OID,
+								 indexId);
+
 	/*
 	 * Open the target index relation and get an exclusive lock on it, to
 	 * ensure that no one else is touching this particular index.
 	 */
 	iRel = index_open(indexId, AccessExclusiveLock);
 
+	pgstat_progress_update_param(PROGRESS_CREATEIDX_ACCESS_METHOD_OID,
+								 iRel->rd_rel->relam);
+
 	/*
 	 * The case of reindexing partitioned tables and indexes is handled
 	 * differently by upper layers, so this case shouldn't arise.
@@ -3442,6 +3450,8 @@ reindex_index(Oid indexId, bool skip_constraint_checks, char persistence,
 				 errdetail_internal("%s",
 									pg_rusage_show(&ru0))));
 
+	pgstat_progress_end_command();
+
 	/* Close rels, but keep locks */
 	index_close(iRel, NoLock);
 	table_close(heapRelation, NoLock);
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 72f786d6f8..16e456a7d9 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -933,7 +933,7 @@ CREATE VIEW pg_stat_progress_cluster AS
                       WHEN 6 THEN 'rebuilding index'
                       WHEN 7 THEN 'performing final cleanup'
                       END AS phase,
-        S.param3 AS cluster_index_relid,
+        CAST(S.param3 AS oid) AS cluster_index_relid,
         S.param4 AS heap_tuples_scanned,
         S.param5 AS heap_tuples_written,
         S.param6 AS heap_blks_total,
@@ -946,16 +946,19 @@ CREATE VIEW pg_stat_progress_create_index AS
 	SELECT
 		S.pid AS pid, S.datid AS datid, D.datname AS datname,
 		S.relid AS relid,
+		CAST(S.param7 AS oid) AS index_relid,
 		CASE S.param10 WHEN 0 THEN 'initializing'
-					  WHEN 1 THEN 'waiting for old snapshots'
+					  WHEN 1 THEN 'waiting for writers before build'
 					  WHEN 2 THEN 'building index' ||
 						COALESCE((': ' || pg_indexam_progress_phasename(S.param9::oid, S.param11)),
 							'')
-					  WHEN 3 THEN 'waiting for writer snapshots'
+					  WHEN 3 THEN 'waiting for writers before validation'
 					  WHEN 4 THEN 'index validation: scanning index'
 					  WHEN 5 THEN 'index validation: sorting tuples'
 					  WHEN 6 THEN 'index validation: scanning table'
-					  WHEN 7 THEN 'waiting for reader snapshots'
+					  WHEN 7 THEN 'waiting for old snapshots'
+					  WHEN 8 THEN 'waiting for readers before marking dead'
+					  WHEN 9 THEN 'waiting for readers before dropping'
 					  END as phase,
 		S.param4 AS lockers_total,
 		S.param5 AS lockers_done,
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 348d543297..4a9b030c2c 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -478,6 +478,12 @@ DefineIndex(Oid relationId,
 		pgstat_progress_start_command(PROGRESS_COMMAND_CREATE_INDEX,
 									  relationId);
 
+	/*
+	 * No index OID to report yet
+	 */
+	pgstat_progress_update_param(PROGRESS_CREATEIDX_INDEX_OID,
+								 InvalidOid);
+
 	/*
 	 * count key attributes in index
 	 */
@@ -1244,6 +1250,12 @@ DefineIndex(Oid relationId,
 	CommitTransactionCommand();
 	StartTransactionCommand();
 
+	/*
+	 * The index is now visible, so we can report the OID.
+	 */
+	pgstat_progress_update_param(PROGRESS_CREATEIDX_INDEX_OID,
+								 indexRelationId);
+
 	/*
 	 * Phase 2 of concurrent index build (see comments for validate_index()
 	 * for an overview of how this works)
@@ -2873,6 +2885,13 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
+		pgstat_progress_start_command(PROGRESS_COMMAND_CREATE_INDEX,
+									  RelationGetRelid(heapRel));
+		pgstat_progress_update_param(PROGRESS_CREATEIDX_INDEX_OID,
+									 indexId);
+		pgstat_progress_update_param(PROGRESS_CREATEIDX_ACCESS_METHOD_OID,
+									 indexRel->rd_rel->relam);
+
 		/* Choose a temporary relation name for the new index */
 		concurrentName = ChooseRelationName(get_rel_name(indexId),
 											NULL,
@@ -2967,7 +2986,9 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 	 * DefineIndex() for more details.
 	 */
 
-	WaitForLockersMultiple(lockTags, ShareLock, false);
+	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
+								 PROGRESS_CREATEIDX_PHASE_WAIT_1);
+	WaitForLockersMultiple(lockTags, ShareLock, true);
 	CommitTransactionCommand();
 
 	forboth(lc, indexIds, lc2, newIndexIds)
@@ -3009,7 +3030,9 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 	 * for more details.
 	 */
 
-	WaitForLockersMultiple(lockTags, ShareLock, false);
+	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
+								 PROGRESS_CREATEIDX_PHASE_WAIT_2);
+	WaitForLockersMultiple(lockTags, ShareLock, true);
 	CommitTransactionCommand();
 
 	foreach(lc, newIndexIds)
@@ -3057,6 +3080,8 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 		 * before the reference snap was taken, we have to wait out any
 		 * transactions that might have older snapshots.
 		 */
+		pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
+									 PROGRESS_CREATEIDX_PHASE_WAIT_3);
 		WaitForOlderSnapshots(limitXmin, false);
 
 		CommitTransactionCommand();
@@ -3128,7 +3153,9 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 	 * index_drop() for more details.
 	 */
 
-	WaitForLockersMultiple(lockTags, AccessExclusiveLock, false);
+	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
+								 PROGRESS_CREATEIDX_PHASE_WAIT_4);
+	WaitForLockersMultiple(lockTags, AccessExclusiveLock, true);
 
 	foreach(lc, indexIds)
 	{
@@ -3150,7 +3177,9 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 	 * Drop the old indexes.
 	 */
 
-	WaitForLockersMultiple(lockTags, AccessExclusiveLock, false);
+	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
+								 PROGRESS_CREATEIDX_PHASE_WAIT_4);
+	WaitForLockersMultiple(lockTags, AccessExclusiveLock, true);
 
 	PushActiveSnapshot(GetTransactionSnapshot());
 
@@ -3225,6 +3254,8 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 
 	MemoryContextDelete(private_context);
 
+	pgstat_progress_end_command();
+
 	return true;
 }
 
diff --git a/src/include/commands/progress.h b/src/include/commands/progress.h
index f046fa13b1..37043e926d 100644
--- a/src/include/commands/progress.h
+++ b/src/include/commands/progress.h
@@ -59,6 +59,7 @@
 
 /* Progress parameters for CREATE INDEX */
 /* 3, 4 and 5 reserved for "waitfor" metrics */
+#define PROGRESS_CREATEIDX_INDEX_OID			6
 #define PROGRESS_CREATEIDX_ACCESS_METHOD_OID	8
 #define PROGRESS_CREATEIDX_PHASE				9	/* AM-agnostic phase # */
 #define PROGRESS_CREATEIDX_SUBPHASE				10	/* phase # filled by AM */
@@ -76,6 +77,8 @@
 #define PROGRESS_CREATEIDX_PHASE_VALIDATE_SORT		5
 #define PROGRESS_CREATEIDX_PHASE_VALIDATE_TABLESCAN	6
 #define PROGRESS_CREATEIDX_PHASE_WAIT_3			7
+#define PROGRESS_CREATEIDX_PHASE_WAIT_4			8
+#define PROGRESS_CREATEIDX_PHASE_WAIT_5			9
 
 /*
  * Subphases of CREATE INDEX, for index_build.
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index bf7fca54ee..4638374a76 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1855,7 +1855,7 @@ pg_stat_progress_cluster| SELECT s.pid,
             WHEN 7 THEN 'performing final cleanup'::text
             ELSE NULL::text
         END AS phase,
-    s.param3 AS cluster_index_relid,
+    (s.param3)::oid AS cluster_index_relid,
     s.param4 AS heap_tuples_scanned,
     s.param5 AS heap_tuples_written,
     s.param6 AS heap_blks_total,
@@ -1867,15 +1867,18 @@ pg_stat_progress_create_index| SELECT s.pid,
     s.datid,
     d.datname,
     s.relid,
+    (s.param7)::oid AS index_relid,
         CASE s.param10
             WHEN 0 THEN 'initializing'::text
-            WHEN 1 THEN 'waiting for old snapshots'::text
+            WHEN 1 THEN 'waiting for writers before build'::text
             WHEN 2 THEN ('building index'::text || COALESCE((': '::text || pg_indexam_progress_phasename((s.param9)::oid, s.param11)), ''::text))
-            WHEN 3 THEN 'waiting for writer snapshots'::text
+            WHEN 3 THEN 'waiting for writers before validation'::text
             WHEN 4 THEN 'index validation: scanning index'::text
             WHEN 5 THEN 'index validation: sorting tuples'::text
             WHEN 6 THEN 'index validation: scanning table'::text
-            WHEN 7 THEN 'waiting for reader snapshots'::text
+            WHEN 7 THEN 'waiting for old snapshots'::text
+            WHEN 8 THEN 'waiting for readers before marking dead'::text
+            WHEN 9 THEN 'waiting for readers before dropping'::text
             ELSE NULL::text
         END AS phase,
     s.param4 AS lockers_total,
-- 
2.21.0