[PG-644] Add option to disable application name tracking (#469)

* Cache application name for every backed instance

* Improve pg_get_backend_status performance for PG16 and PG17

* Fix

* Make application_name tracking disabled by default

* Meke app name tracking opt-out

* Format newly added code with pgindent

* Fix build for PG17

* Fix

guc.c

@@ -33,6 +33,7 @@ bool		pgsm_enable_query_plan;
 bool		pgsm_enable_overflow;
 bool		pgsm_normalized_query;
 bool		pgsm_track_utility;
+bool		pgsm_track_application_names;
 bool		pgsm_enable_pgsm_query_id;
 int			pgsm_track;
 static int	pgsm_overflow_target;	/* Not used since 2.0 */
@@ -190,6 +191,18 @@ init_guc(void)
 							 NULL	/* show_hook */
 		);
 
+	DefineCustomBoolVariable("pg_stat_monitor.pgsm_track_application_names",	/* name */
+							 "Enable/Disable application names tracking.",	/* short_desc */
+							 NULL,	/* long_desc */
+							 &pgsm_track_application_names, /* value address */
+							 true,	/* boot value */
+							 PGC_USERSET,	/* context */
+							 0, /* flags */
+							 NULL,	/* check_hook */
+							 NULL,	/* assign_hook */
+							 NULL	/* show_hook */
+		);
+
 	DefineCustomBoolVariable("pg_stat_monitor.pgsm_enable_pgsm_query_id",	/* name */
 							 "Enable/disable PGSM specific query id calculation which is very useful in comparing same query across databases and clusters..",	/* short_desc */
 							 NULL,	/* long_desc */

pg_stat_monitor.c

@@ -43,7 +43,7 @@ PG_MODULE_MAGIC;
 #define PG_STAT_MONITOR_COLS_V1_0    52
 #define PG_STAT_MONITOR_COLS_V2_0    64
 #define PG_STAT_MONITOR_COLS_V2_1    70
-#define PG_STAT_MONITOR_COLS         PG_STAT_MONITOR_COLS_V2_0	/* maximum of above */
+#define PG_STAT_MONITOR_COLS         PG_STAT_MONITOR_COLS_V2_1	/* maximum of above */
 
 #define PGSM_TEXT_FILE PGSTAT_STAT_PERMANENT_DIRECTORY "pg_stat_monitor_query"
 
@@ -106,8 +106,8 @@ static struct rusage rusage_start;
 static struct rusage rusage_end;
 
 /* Application name and length; set each time when an entry is created locally */
-char		app_name[APPLICATIONNAME_LEN];
+static char app_name[APPLICATIONNAME_LEN];
-int			app_name_len;
+static int	app_name_len;
 
 
 /* Query buffer, store queries' text. */
@@ -1334,6 +1334,12 @@ pgsm_hash_string(const char *str, int len)
 static PgBackendStatus *
 pg_get_backend_status(void)
 {
+
+#if PG_VERSION_NUM >= 170000
+	return pgstat_get_beentry_by_proc_number(MyProcPid);
+#elif PG_VERSION_NUM >= 160000
+	return &(pgstat_get_local_beentry_by_backend_id(MyBackendId)->backendStatus);
+#else
 	LocalPgBackendStatus *local_beentry;
 	int			num_backends = pgstat_fetch_stat_numbackends();
 	int			i;
@@ -1341,11 +1347,8 @@ pg_get_backend_status(void)
 	for (i = 1; i <= num_backends; i++)
 	{
 		PgBackendStatus *beentry;
-#if PG_VERSION_NUM < 160000
+
 		local_beentry = pgstat_fetch_stat_local_beentry(i);
-#else
-		local_beentry = pgstat_get_local_beentry_by_index(i);
-#endif
 		if (!local_beentry)
 			continue;
 
@@ -1355,6 +1358,8 @@ pg_get_backend_status(void)
 			return beentry;
 	}
 	return NULL;
+
+#endif
 }
 
 /*
@@ -1531,7 +1536,7 @@ pgsm_update_entry(pgsmEntry * entry,
 		/* Only should process this once when storing the data */
 		if (kind == PGSM_STORE)
 		{
-			if (app_name_len > 0 && !e->counters.info.application_name[0])
+			if (pgsm_track_application_names && app_name_len > 0 && !e->counters.info.application_name[0])
 				_snprintf(e->counters.info.application_name, app_name, app_name_len + 1, APPLICATIONNAME_LEN);
 
 			e->counters.info.num_relations = num_relations;
@@ -1787,7 +1792,6 @@ pgsm_create_hash_entry(uint64 bucket_id, uint64 queryid, PlanInfo * plan_info)
 	pgsmEntry  *entry;
 	int			sec_ctx;
 	bool		found_client_addr = false;
-	char	   *app_name_ptr = app_name;
 	MemoryContext oldctx;
 	char	   *datname = NULL;
 	char	   *username = NULL;
@@ -1802,9 +1806,12 @@ pgsm_create_hash_entry(uint64 bucket_id, uint64 queryid, PlanInfo * plan_info)
 	 */
 	GetUserIdAndSecContext((Oid *) &entry->key.userid, &sec_ctx);
 
+	if (pgsm_track_application_names)
+	{
 		/* Get the application name and set appid */
 		app_name_len = pg_get_application_name(app_name, APPLICATIONNAME_LEN);
-	entry->key.appid = pgsm_hash_string((const char *) app_name_ptr, app_name_len);
+		entry->key.appid = pgsm_hash_string((const char *) app_name, app_name_len);
+	}
 
 	/* client address */
 	if (!pgsm_client_ip_is_valid())

pg_stat_monitor.h

@@ -521,6 +521,7 @@ extern bool pgsm_enable_query_plan;
 extern bool pgsm_enable_overflow;
 extern bool pgsm_normalized_query;
 extern bool pgsm_track_utility;
+extern bool pgsm_track_application_names;
 extern bool pgsm_enable_pgsm_query_id;
 extern int	pgsm_track;
 

regression/expected/application_name.out

@@ -24,4 +24,32 @@ SELECT pg_stat_monitor_reset();
  
 (1 row)
 
+SELECT 1 AS num;
+ num 
+-----
+   1
+(1 row)
+
+SET pg_stat_monitor.pgsm_track_application_names='no';
+SELECT 1 AS num;
+ num 
+-----
+   1
+(1 row)
+
+SELECT query,application_name FROM pg_stat_monitor ORDER BY query, application_name COLLATE "C";
+                         query                         |      application_name       
+-------------------------------------------------------+-----------------------------
+ SELECT 1 AS num                                       | pg_regress/application_name
+ SELECT 1 AS num                                       | 
+ SELECT pg_stat_monitor_reset()                        | pg_regress/application_name
+ SET pg_stat_monitor.pgsm_track_application_names='no' | 
+(4 rows)
+
+SELECT pg_stat_monitor_reset();
+ pg_stat_monitor_reset 
+-----------------------
+ 
+(1 row)
+
 DROP EXTENSION pg_stat_monitor;

regression/expected/guc.out

@@ -17,7 +17,7 @@ ORDER
 BY      name
 COLLATE "C";
                      name                     | setting | unit |  context   | vartype | source  | min_val |  max_val   |    enumvals    | boot_val | reset_val | pending_restart 
--------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
+----------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
  pg_stat_monitor.pgsm_bucket_time             | 60      | s    | postmaster | integer | default | 1       | 2147483647 |                | 60       | 60        | f
  pg_stat_monitor.pgsm_enable_overflow         | on      |      | postmaster | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_enable_pgsm_query_id    | on      |      | user       | bool    | default |         |            |                | on       | on        | f
@@ -33,8 +33,9 @@ COLLATE "C";
  pg_stat_monitor.pgsm_query_max_len           | 2048    |      | postmaster | integer | default | 1024    | 2147483647 |                | 2048     | 2048      | f
  pg_stat_monitor.pgsm_query_shared_buffer     | 20      | MB   | postmaster | integer | default | 1       | 10000      |                | 20       | 20        | f
  pg_stat_monitor.pgsm_track                   | top     |      | user       | enum    | default |         |            | {none,top,all} | top      | top       | f
+ pg_stat_monitor.pgsm_track_application_names | on      |      | user       | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_track_planning          | off     |      | user       | bool    | default |         |            |                | off      | off       | f
  pg_stat_monitor.pgsm_track_utility           | on      |      | user       | bool    | default |         |            |                | on       | on        | f
-(17 rows)
+(18 rows)
 
 DROP EXTENSION pg_stat_monitor;

regression/expected/guc_1.out

@@ -17,7 +17,7 @@ ORDER
 BY      name
 COLLATE "C";
                      name                     | setting | unit |  context   | vartype | source  | min_val |  max_val   |    enumvals    | boot_val | reset_val | pending_restart 
--------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
+----------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
  pg_stat_monitor.pgsm_bucket_time             | 60      | s    | postmaster | integer | default | 1       | 2147483647 |                | 60       | 60        | f
  pg_stat_monitor.pgsm_enable_overflow         | on      |      | postmaster | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_enable_pgsm_query_id    | on      |      | user       | bool    | default |         |            |                | on       | on        | f
@@ -33,7 +33,8 @@ COLLATE "C";
  pg_stat_monitor.pgsm_query_max_len           | 2048    |      | postmaster | integer | default | 1024    | 2147483647 |                | 2048     | 2048      | f
  pg_stat_monitor.pgsm_query_shared_buffer     | 20      | MB   | postmaster | integer | default | 1       | 10000      |                | 20       | 20        | f
  pg_stat_monitor.pgsm_track                   | top     |      | user       | enum    | default |         |            | {none,top,all} | top      | top       | f
+ pg_stat_monitor.pgsm_track_application_names | on      |      | user       | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_track_utility           | on      |      | user       | bool    | default |         |            |                | on       | on        | f
-(16 rows)
+(17 rows)
 
 DROP EXTENSION pg_stat_monitor;

regression/expected/guc_2.out

@@ -17,7 +17,7 @@ ORDER
 BY      name
 COLLATE "C";
                      name                     | setting | unit |  context   | vartype | source  | min_val |  max_val   |    enumvals    | boot_val | reset_val | pending_restart 
--------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
+----------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
  pg_stat_monitor.pgsm_bucket_time             | 60      | s    | postmaster | integer | default | 1       | 2147483647 |                | 60       | 60        | f
  pg_stat_monitor.pgsm_enable_overflow         | on      |      | postmaster | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_enable_pgsm_query_id    | on      |      | user       | bool    | default |         |            |                | on       | on        | f
@@ -33,7 +33,8 @@ COLLATE "C";
  pg_stat_monitor.pgsm_query_max_len           | 2048    |      | postmaster | integer | default | 1024    | 2147483647 |                | 2048     | 2048      | f
  pg_stat_monitor.pgsm_query_shared_buffer     | 20      | MB   | postmaster | integer | default | 1       | 10000      |                | 20       | 20        | f
  pg_stat_monitor.pgsm_track                   | top     |      | user       | enum    | default |         |            | {none,top,all} | top      | top       | f
+ pg_stat_monitor.pgsm_track_application_names | on      |      | user       | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_track_utility           | on      |      | user       | bool    | default |         |            |                | on       | on        | f
-(16 rows)
+(17 rows)
 
 DROP EXTENSION pg_stat_monitor;

regression/sql/application_name.sql

@@ -1,6 +1,14 @@
 CREATE EXTENSION pg_stat_monitor;
 SELECT pg_stat_monitor_reset();
+
 SELECT 1 AS num;
 SELECT query,application_name FROM pg_stat_monitor ORDER BY query COLLATE "C";
 SELECT pg_stat_monitor_reset();
+
+SELECT 1 AS num;
+SET pg_stat_monitor.pgsm_track_application_names='no';
+SELECT 1 AS num;
+SELECT query,application_name FROM pg_stat_monitor ORDER BY query, application_name COLLATE "C";
+SELECT pg_stat_monitor_reset();
+
 DROP EXTENSION pg_stat_monitor;

t/expected/001_settings_default.out

@@ -7,7 +7,7 @@ SELECT pg_stat_monitor_reset();
 
 SELECT name, setting, unit, context, vartype, source, min_val, max_val, enumvals, boot_val, reset_val, pending_restart FROM pg_settings WHERE name LIKE '%pg_stat_monitor%';
                      name                     | setting | unit |  context   | vartype | source  | min_val |  max_val   |    enumvals    | boot_val | reset_val | pending_restart 
--------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
+----------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
  pg_stat_monitor.pgsm_bucket_time             | 60      | s    | postmaster | integer | default | 1       | 2147483647 |                | 60       | 60        | f
  pg_stat_monitor.pgsm_enable_overflow         | on      |      | postmaster | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_enable_pgsm_query_id    | on      |      | user       | bool    | default |         |            |                | on       | on        | f
@@ -23,9 +23,10 @@ SELECT name, setting, unit, context, vartype, source, min_val, max_val, enumvals
  pg_stat_monitor.pgsm_query_max_len           | 2048    |      | postmaster | integer | default | 1024    | 2147483647 |                | 2048     | 2048      | f
  pg_stat_monitor.pgsm_query_shared_buffer     | 20      | MB   | postmaster | integer | default | 1       | 10000      |                | 20       | 20        | f
  pg_stat_monitor.pgsm_track                   | top     |      | user       | enum    | default |         |            | {none,top,all} | top      | top       | f
+ pg_stat_monitor.pgsm_track_application_names | on      |      | user       | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_track_planning          | off     |      | user       | bool    | default |         |            |                | off      | off       | f
  pg_stat_monitor.pgsm_track_utility           | on      |      | user       | bool    | default |         |            |                | on       | on        | f
-(17 rows)
+(18 rows)
 
 SELECT datname, substr(query,0,100) AS query, calls FROM pg_stat_monitor ORDER BY datname, query, calls DESC Limit 20;
  datname  |                                                query                                                | calls 
@@ -36,7 +37,7 @@ SELECT datname, substr(query,0,100) AS query, calls FROM pg_stat_monitor ORDER B
 
 SELECT name, setting, unit, context, vartype, source, min_val, max_val, enumvals, boot_val, reset_val, pending_restart FROM pg_settings WHERE name LIKE '%pg_stat_monitor%';
                      name                     | setting | unit |  context   | vartype | source  | min_val |  max_val   |    enumvals    | boot_val | reset_val | pending_restart 
--------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
+----------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
  pg_stat_monitor.pgsm_bucket_time             | 60      | s    | postmaster | integer | default | 1       | 2147483647 |                | 60       | 60        | f
  pg_stat_monitor.pgsm_enable_overflow         | on      |      | postmaster | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_enable_pgsm_query_id    | on      |      | user       | bool    | default |         |            |                | on       | on        | f
@@ -52,9 +53,10 @@ SELECT name, setting, unit, context, vartype, source, min_val, max_val, enumvals
  pg_stat_monitor.pgsm_query_max_len           | 2048    |      | postmaster | integer | default | 1024    | 2147483647 |                | 2048     | 2048      | f
  pg_stat_monitor.pgsm_query_shared_buffer     | 20      | MB   | postmaster | integer | default | 1       | 10000      |                | 20       | 20        | f
  pg_stat_monitor.pgsm_track                   | top     |      | user       | enum    | default |         |            | {none,top,all} | top      | top       | f
+ pg_stat_monitor.pgsm_track_application_names | on      |      | user       | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_track_planning          | off     |      | user       | bool    | default |         |            |                | off      | off       | f
  pg_stat_monitor.pgsm_track_utility           | on      |      | user       | bool    | default |         |            |                | on       | on        | f
-(17 rows)
+(18 rows)
 
 SELECT pg_stat_monitor_reset();
  pg_stat_monitor_reset 

t/expected/001_settings_default.out.12

@@ -7,7 +7,7 @@ SELECT pg_stat_monitor_reset();
 
 SELECT name, setting, unit, context, vartype, source, min_val, max_val, enumvals, boot_val, reset_val, pending_restart FROM pg_settings WHERE name LIKE '%pg_stat_monitor%';
                      name                     | setting | unit |  context   | vartype | source  | min_val |  max_val   |    enumvals    | boot_val | reset_val | pending_restart 
--------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
+----------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
  pg_stat_monitor.pgsm_bucket_time             | 60      | s    | postmaster | integer | default | 1       | 2147483647 |                | 60       | 60        | f
  pg_stat_monitor.pgsm_enable_overflow         | on      |      | postmaster | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_enable_pgsm_query_id    | on      |      | user       | bool    | default |         |            |                | on       | on        | f
@@ -23,8 +23,9 @@ SELECT name, setting, unit, context, vartype, source, min_val, max_val, enumvals
  pg_stat_monitor.pgsm_query_max_len           | 2048    |      | postmaster | integer | default | 1024    | 2147483647 |                | 2048     | 2048      | f
  pg_stat_monitor.pgsm_query_shared_buffer     | 20      | MB   | postmaster | integer | default | 1       | 10000      |                | 20       | 20        | f
  pg_stat_monitor.pgsm_track                   | top     |      | user       | enum    | default |         |            | {none,top,all} | top      | top       | f
+ pg_stat_monitor.pgsm_track_application_names | on      |      | user       | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_track_utility           | on      |      | user       | bool    | default |         |            |                | on       | on        | f
-(16 rows)
+(17 rows)
 
 SELECT datname, substr(query,0,100) AS query, calls FROM pg_stat_monitor ORDER BY datname, query, calls DESC Limit 20;
  datname  |                                                query                                                | calls 
@@ -35,7 +36,7 @@ SELECT datname, substr(query,0,100) AS query, calls FROM pg_stat_monitor ORDER B
 
 SELECT name, setting, unit, context, vartype, source, min_val, max_val, enumvals, boot_val, reset_val, pending_restart FROM pg_settings WHERE name LIKE '%pg_stat_monitor%';
                      name                     | setting | unit |  context   | vartype | source  | min_val |  max_val   |    enumvals    | boot_val | reset_val | pending_restart 
--------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
+----------------------------------------------+---------+------+------------+---------+---------+---------+------------+----------------+----------+-----------+-----------------
  pg_stat_monitor.pgsm_bucket_time             | 60      | s    | postmaster | integer | default | 1       | 2147483647 |                | 60       | 60        | f
  pg_stat_monitor.pgsm_enable_overflow         | on      |      | postmaster | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_enable_pgsm_query_id    | on      |      | user       | bool    | default |         |            |                | on       | on        | f
@@ -51,8 +52,9 @@ SELECT name, setting, unit, context, vartype, source, min_val, max_val, enumvals
  pg_stat_monitor.pgsm_query_max_len           | 2048    |      | postmaster | integer | default | 1024    | 2147483647 |                | 2048     | 2048      | f
  pg_stat_monitor.pgsm_query_shared_buffer     | 20      | MB   | postmaster | integer | default | 1       | 10000      |                | 20       | 20        | f
  pg_stat_monitor.pgsm_track                   | top     |      | user       | enum    | default |         |            | {none,top,all} | top      | top       | f
+ pg_stat_monitor.pgsm_track_application_names | on      |      | user       | bool    | default |         |            |                | on       | on        | f
  pg_stat_monitor.pgsm_track_utility           | on      |      | user       | bool    | default |         |            |                | on       | on        | f
-(16 rows)
+(17 rows)
 
 SELECT pg_stat_monitor_reset();
  pg_stat_monitor_reset