Fix test case added by commit f5fc2f5b23.

In the new test after resetting the stats, we were not waiting for the
stats message to be delivered. Also, we need to decode the results for
the new test, otherwise, it will show the old stats.

In passing,
a. Change docs added by commit f5fc2f5b23 as per suggestion by
Justin Pryzby.
b. Bump the PGSTAT_FILE_FORMAT_ID as commit f5fc2f5b23 changes the file
format of stats.

Reported-by: Tom Lane based on buildfarm reports
Author: Vignesh C, Justin Pryzby
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de

diff --git a/contrib/test_decoding/expected/stats.out b/contrib/test_decoding/expected/stats.out
index bc8e601eab6b267182818d7016bc039940dd5941..86d594ca15ef8d3bd50ae93da7e9a245d4e7a08d 100644 (file)
--- a/contrib/test_decoding/expected/stats.out
+++ b/contrib/test_decoding/expected/stats.out
@@ -51,39 +51,34 @@ BEGIN
     extract(epoch from clock_timestamp() - start_time);
 END
 $$ LANGUAGE plpgsql;
--- spilling the xact
-BEGIN;
-INSERT INTO stats_test SELECT 'serialize-topbig--1:'||g.i FROM generate_series(1, 5000) g(i);
-COMMIT;
-SELECT count(*) FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL, 'skip-empty-xacts', '1');
+-- non-spilled xact
+INSERT INTO stats_test values(1);
+SELECT count(*) FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'skip-empty-xacts', '1');
  count 
 -------
-  5002
+     3
 (1 row)
 
--- Check stats, wait for the stats collector to update. We can't test the
--- exact stats count as that can vary if any background transaction (say by
--- autovacuum) happens in parallel to the main transaction.
-SELECT wait_for_decode_stats(false, true);
+SELECT wait_for_decode_stats(false, false);
  wait_for_decode_stats 
 -----------------------
  
 (1 row)
 
-SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
+SELECT slot_name, spill_txns = 0 AS spill_txns, spill_count = 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
     slot_name    | spill_txns | spill_count | total_txns | total_bytes 
 -----------------+------------+-------------+------------+-------------
  regression_slot | t          | t           | t          | t
 (1 row)
 
--- reset the slot stats, and wait for stats collector to reset
+-- reset the slot stats, and wait for stats collector's total txn to reset
 SELECT pg_stat_reset_replication_slot('regression_slot');
  pg_stat_reset_replication_slot 
 --------------------------------
  
 (1 row)
 
-SELECT wait_for_decode_stats(true, true);
+SELECT wait_for_decode_stats(true, false);
  wait_for_decode_stats 
 -----------------------
  
@@ -95,13 +90,19 @@ SELECT slot_name, spill_txns, spill_count, total_txns, total_bytes FROM pg_stat_
  regression_slot |          0 |           0 |          0 |           0
 (1 row)
 
--- decode and check stats again.
+-- spilling the xact
+BEGIN;
+INSERT INTO stats_test SELECT 'serialize-topbig--1:'||g.i FROM generate_series(1, 5000) g(i);
+COMMIT;
 SELECT count(*) FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL, 'skip-empty-xacts', '1');
  count 
 -------
   5002
 (1 row)
 
+-- Check stats, wait for the stats collector to update. We can't test the
+-- exact stats count as that can vary if any background transaction (say by
+-- autovacuum) happens in parallel to the main transaction.
 SELECT wait_for_decode_stats(false, true);
  wait_for_decode_stats 
 -----------------------
@@ -114,24 +115,42 @@ SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count,
  regression_slot | t          | t           | t          | t
 (1 row)
 
+-- reset the slot stats, and wait for stats collector to reset
 SELECT pg_stat_reset_replication_slot('regression_slot');
  pg_stat_reset_replication_slot 
 --------------------------------
  
 (1 row)
 
--- non-spilled xact
-INSERT INTO stats_test values(generate_series(1, 10));
-SELECT wait_for_decode_stats(false, false);
+SELECT wait_for_decode_stats(true, true);
  wait_for_decode_stats 
 -----------------------
  
 (1 row)
 
-SELECT slot_name, spill_txns = 0 AS spill_txns, spill_count = 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
+SELECT slot_name, spill_txns, spill_count, total_txns, total_bytes FROM pg_stat_replication_slots;
     slot_name    | spill_txns | spill_count | total_txns | total_bytes 
 -----------------+------------+-------------+------------+-------------
- regression_slot | f          | f           | t          | t
+ regression_slot |          0 |           0 |          0 |           0
+(1 row)
+
+-- decode and check stats again.
+SELECT count(*) FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL, 'skip-empty-xacts', '1');
+ count 
+-------
+  5002
+(1 row)
+
+SELECT wait_for_decode_stats(false, true);
+ wait_for_decode_stats 
+-----------------------
+ 
+(1 row)
+
+SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
+    slot_name    | spill_txns | spill_count | total_txns | total_bytes 
+-----------------+------------+-------------+------------+-------------
+ regression_slot | t          | t           | t          | t
 (1 row)
 
 -- Ensure stats can be repeatedly accessed using the same stats snapshot. See

diff --git a/contrib/test_decoding/sql/stats.sql b/contrib/test_decoding/sql/stats.sql
index 8c34aeced1de0d4c045b6835e844792f7d2b2edc..03fc27e537f4d76c8dde3a87964d49ae5f0e6655 100644 (file)
--- a/contrib/test_decoding/sql/stats.sql
+++ b/contrib/test_decoding/sql/stats.sql
@@ -50,6 +50,17 @@ BEGIN
 END
 $$ LANGUAGE plpgsql;
 
+-- non-spilled xact
+INSERT INTO stats_test values(1);
+SELECT count(*) FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'skip-empty-xacts', '1');
+SELECT wait_for_decode_stats(false, false);
+SELECT slot_name, spill_txns = 0 AS spill_txns, spill_count = 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
+
+-- reset the slot stats, and wait for stats collector's total txn to reset
+SELECT pg_stat_reset_replication_slot('regression_slot');
+SELECT wait_for_decode_stats(true, false);
+SELECT slot_name, spill_txns, spill_count, total_txns, total_bytes FROM pg_stat_replication_slots;
+
 -- spilling the xact
 BEGIN;
 INSERT INTO stats_test SELECT 'serialize-topbig--1:'||g.i FROM generate_series(1, 5000) g(i);
@@ -72,13 +83,6 @@ SELECT count(*) FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL,
 SELECT wait_for_decode_stats(false, true);
 SELECT slot_name, spill_txns > 0 AS spill_txns, spill_count > 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
 
-SELECT pg_stat_reset_replication_slot('regression_slot');
-
--- non-spilled xact
-INSERT INTO stats_test values(generate_series(1, 10));
-SELECT wait_for_decode_stats(false, false);
-SELECT slot_name, spill_txns = 0 AS spill_txns, spill_count = 0 AS spill_count, total_txns > 0 AS total_txns, total_bytes > 0 AS total_bytes FROM pg_stat_replication_slots;
-
 -- Ensure stats can be repeatedly accessed using the same stats snapshot. See
 -- https://postgr.es/m/20210317230447.c7uc4g3vbs4wi32i%40alap3.anarazel.de
 BEGIN;

diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index c44d087508093eb2657831426392e101bb3b0a80..5cf083bb7761e438526feed191906680244a7589 100644 (file)
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -2722,9 +2722,9 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
        </para>
        <para>
         Number of decoded transactions sent to the decoding output plugin for
-        this slot. This counter is used to maintain the top level transactions,
-        so the counter is not incremented for subtransactions. Note that this
-        includes the transactions that are streamed and/or spilled.
+        this slot. This counts toplevel transactions only, and is not incremented
+        for subtransactions. Note that this includes the transactions that are
+        streamed and/or spilled.
        </para></entry>
      </row>
 
@@ -2733,10 +2733,10 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
         <structfield>total_bytes</structfield><type>bigint</type>
        </para>
        <para>
-        Amount of decoded transactions data sent to the decoding output plugin
+        Amount of decoded transaction data sent to the decoding output plugin
         while decoding the changes from WAL for this slot. This can be used to
         gauge the total amount of data sent during logical decoding. Note that
-        this includes the data that is streamed and/or spilled.
+        this includes data that is streamed and/or spilled.
        </para>
       </entry>
      </row>

diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 2aeb3cded4d71c9a462b4f8af36647c25de0282a..5c5920b0b5f0dd6471bf4f4ed4524a5c1097f0c9 100644 (file)
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -744,7 +744,7 @@ typedef union PgStat_Msg
  * ------------------------------------------------------------
  */
 
-#define PGSTAT_FILE_FORMAT_ID  0x01A5BCA1
+#define PGSTAT_FILE_FORMAT_ID  0x01A5BCA2
 
 /* ----------
  * PgStat_StatDBEntry          The collector's data per database