Re: Is autovacuum doing a wraparound-avoiding VACUUM?

Simon Riggs <[email protected]> Sat, 19 Jul 2008 09:04:08 +0100
Newsgroups gmane.comp.db.postgresql.devel.patches
Message-ID <[email protected]> 
On Fri, 2008-07-18 at 01:44 -0400, Tom Lane wrote:
> Simon Riggs <[email protected]> writes:
> > On Thu, 2008-07-17 at 17:10 -0400, Alvaro Herrera wrote:
> >> I don't like your wording though; it feels too verbose (and you're
> >> losing the ANALYZE in case it's doing both things).  How about 
> >> 
> >> snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
> >> "autovacuum: VACUUM%s%s", vac
> >> tab->at_doanalyze ? " ANALYZE" : "",
> >> tab->at_wraparound ? " (wraparound)" : "");
> 
> > Yes, looks good.
> 
> May I suggest "(to prevent wraparound)" or something like that?
> Otherwise, +1.
> 
> >> You're not proposing it for 8.3 right?
> 
> > I think I am. It's an important diagnostic for your other fix.
> 
> I agree, this is important for visibility into what's happening.
> The string isn't getting translated so I don't see any big downside
> to applying the patch in back branches.

Patches for 8.3 and CVS HEAD.

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 Simon Riggs           www.2ndQuadrant.com
 PostgreSQL Training, Services and Support


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wraparound_msg.v2.CVS_HEAD.patch (text/x-patch, 1 KB) 
Index: src/backend/postmaster/autovacuum.c
===================================================================
RCS file: /home/sriggs/pg/REPOSITORY/pgsql/src/backend/postmaster/autovacuum.c,v
retrieving revision 1.81
diff -c -r1.81 autovacuum.c
*** src/backend/postmaster/autovacuum.c	17 Jul 2008 21:02:31 -0000	1.81
--- src/backend/postmaster/autovacuum.c	19 Jul 2008 07:58:33 -0000
***************
*** 2657,2664 ****
  	/* Report the command and possible options */
  	if (tab->at_dovacuum)
  		snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
! 				 "autovacuum: VACUUM%s",
! 				 tab->at_doanalyze ? " ANALYZE" : "");
  	else
  		snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
  				 "autovacuum: ANALYZE");
--- 2657,2665 ----
  	/* Report the command and possible options */
  	if (tab->at_dovacuum)
  		snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
! 				 "autovacuum: VACUUM%s%s",
! 				 tab->at_doanalyze ? " ANALYZE" : "",
! 				 tab->at_wraparound ? " (to prevent wraparound)" : "");
  	else
  		snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
  				 "autovacuum: ANALYZE");
wraparound_msg.v2.REL8_3_STABLE.patch (text/x-patch, 2.8 KB) 
Index: src/backend/postmaster/autovacuum.c
===================================================================
RCS file: /home/sriggs/pg/REPOSITORY/pgsql/src/backend/postmaster/autovacuum.c,v
retrieving revision 1.71.2.4
diff -c -r1.71.2.4 autovacuum.c
*** src/backend/postmaster/autovacuum.c	17 Jul 2008 21:02:41 -0000	1.71.2.4
--- src/backend/postmaster/autovacuum.c	19 Jul 2008 07:58:43 -0000
***************
*** 291,297 ****
  static PgStat_StatTabEntry *get_pgstat_tabentry_relid(Oid relid, bool isshared,
  						  PgStat_StatDBEntry *shared,
  						  PgStat_StatDBEntry *dbentry);
! static void autovac_report_activity(VacuumStmt *vacstmt, Oid relid);
  static void avl_sighup_handler(SIGNAL_ARGS);
  static void avl_sigusr1_handler(SIGNAL_ARGS);
  static void avl_sigterm_handler(SIGNAL_ARGS);
--- 291,297 ----
  static PgStat_StatTabEntry *get_pgstat_tabentry_relid(Oid relid, bool isshared,
  						  PgStat_StatDBEntry *shared,
  						  PgStat_StatDBEntry *dbentry);
! static void autovac_report_activity(VacuumStmt *vacstmt, Oid relid, bool for_wraparound);
  static void avl_sighup_handler(SIGNAL_ARGS);
  static void avl_sigusr1_handler(SIGNAL_ARGS);
  static void avl_sigterm_handler(SIGNAL_ARGS);
***************
*** 2633,2639 ****
  	MemoryContextSwitchTo(old_cxt);
  
  	/* Let pgstat know what we're doing */
! 	autovac_report_activity(&vacstmt, relid);
  
  	vacuum(&vacstmt, relids, bstrategy, for_wraparound, true);
  }
--- 2633,2639 ----
  	MemoryContextSwitchTo(old_cxt);
  
  	/* Let pgstat know what we're doing */
! 	autovac_report_activity(&vacstmt, relid, for_wraparound);
  
  	vacuum(&vacstmt, relids, bstrategy, for_wraparound, true);
  }
***************
*** 2650,2656 ****
   * bother to report "<IDLE>" or some such.
   */
  static void
! autovac_report_activity(VacuumStmt *vacstmt, Oid relid)
  {
  	char	   *relname = get_rel_name(relid);
  	char	   *nspname = get_namespace_name(get_rel_namespace(relid));
--- 2650,2656 ----
   * bother to report "<IDLE>" or some such.
   */
  static void
! autovac_report_activity(VacuumStmt *vacstmt, Oid relid, bool for_wraparound)
  {
  	char	   *relname = get_rel_name(relid);
  	char	   *nspname = get_namespace_name(get_rel_namespace(relid));
***************
*** 2661,2668 ****
  	/* Report the command and possible options */
  	if (vacstmt->vacuum)
  		snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
! 				 "autovacuum: VACUUM%s",
! 				 vacstmt->analyze ? " ANALYZE" : "");
  	else
  		snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
  				 "autovacuum: ANALYZE");
--- 2661,2669 ----
  	/* Report the command and possible options */
  	if (vacstmt->vacuum)
  		snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
! 				 "autovacuum: VACUUM%s%s",
! 				 vacstmt->analyze ? " ANALYZE" : "",
! 				 for_wraparound ? " (to prevent wraparound)" : "");
  	else
  		snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
  				 "autovacuum: ANALYZE");