Re: [PATCHES] [HACKERS] Minor changes to Recovery related code

2008-04-04 Thread Bruce Momjian

Nice, applied.  I only modified some of the documentation wording.

I was a little worried that statement_timeout might cancel
pg_stop_backup() _before_ it had gotten to waiting for the archive logs
to be saved, but based on what little code there is before that block, I
think we are OK.

---

Simon Riggs wrote:
> On Thu, 2008-03-27 at 17:34 +, Simon Riggs wrote:
> > Follow-up during March 2008 CommitFest
> > 
> > On Thu, 2007-06-07 at 21:53 +0100, Simon Riggs wrote:
> > > On Sat, 2007-03-31 at 00:51 +0200, Florian G. Pflug wrote:
> 
> > > - pg_stop_backup() will wait until the WAL file that ends the backup is
> > > safely archived, even if a failure to archive occurs. This is a change
> > > to current behaviour, but since it implements the originally *expected*
> > > behaviour IMHO it should be the default.
> > 
> > The most straightforward thing is to make pg_stop_backup() wait as
> > described above.
> > 
> > If people want it to timeout, they can use a statement_timeout as
> > suggested by Florian.
> > 
> > This can be implemented by having the function poll in an infinite loop
> > for archive_status/LOG.done. Also, as Florian suggests, we should have
> > it output a WARNING message every 60 seconds.
> > 
> > I'll write a patch now.
> 
> Patch to implement waiting pg_stop_backup(). 
> 
> Tested and ready to apply, includes docs.
> 
> -- 
>   Simon Riggs
>   2ndQuadrant  http://www.2ndQuadrant.com 
> 
>   PostgreSQL UK 2008 Conference: http://www.postgresql.org.uk

[ Attachment, skipping... ]

-- 
  Bruce Momjian  <[EMAIL PROTECTED]>http://momjian.us
  EnterpriseDB http://enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +
Index: doc/src/sgml/backup.sgml
===
RCS file: /cvsroot/pgsql/doc/src/sgml/backup.sgml,v
retrieving revision 2.116
diff -c -c -r2.116 backup.sgml
*** doc/src/sgml/backup.sgml	28 Mar 2008 15:00:28 -	2.116
--- doc/src/sgml/backup.sgml	5 Apr 2008 01:28:09 -
***
*** 761,772 
  
   Once the WAL segment files used during the backup are archived, you are
   done.  The file identified by pg_stop_backup's result is
!  the last segment that needs to be archived to complete the backup.
!  Archival of these files will happen automatically, since you have
!  already configured archive_command. In many cases, this
!  happens fairly quickly, but you are advised to monitor your archival
!  system to ensure this has taken place so that you can be certain you
!  have a complete backup.
  
 

--- 761,779 
  
   Once the WAL segment files used during the backup are archived, you are
   done.  The file identified by pg_stop_backup's result is
!  the last segment that is required to form a complete set of backup files. 
!  pg_stop_backup does not return until the last segment has
!  been archived. 
!  Archiving of these files happens automatically since you have
!  already configured archive_command. In most cases this
!  happens quickly, but you are advised to monitor your archive
!  system to ensure there are no delays.
!  If the archive process has fallen behind
!  because of failures of the archive command, it will keep retrying
!  until the archive succeeds and the backup is complete.
!  If you wish to place a time limit on the execution of
!  pg_stop_backup, set an appropriate
!  statement_timeout value.
  
 

***
*** 1044,1050 
 
   
The stop point must be after the ending time of the base backup, i.e.,
!   the time of pg_stop_backup.  You cannot use a base backup
to recover to a time when that backup was still going on.  (To
recover to such a time, you must go back to your previous base backup
and roll forward from there.)
--- 1051,1057 
 
   
The stop point must be after the ending time of the base backup, i.e.,
!   the end time of pg_stop_backup.  You cannot use a base backup
to recover to a time when that backup was still going on.  (To
recover to such a time, you must go back to your previous base backup
and roll forward from there.)
***
*** 1322,1327 
--- 1329,1335 
After the backup the switch file is removed. Archived WAL files are
then added to the backup so that both base backup and all required
WAL files are part of the same tar file.
+   Please remember to add error handling to your backup scripts.
   
  
  
Index: src/backend/access/transam/xlog.c
===
RCS file: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v
retrieving revision 1.295
diff -c -c -r1.295 xlog.c
*** src/backend/access/transam/xlog.c	25 Mar 2008 22

Re: [PATCHES] [HACKERS] Minor changes to Recovery related code

2008-04-01 Thread Simon Riggs
On Thu, 2008-03-27 at 17:34 +, Simon Riggs wrote:
> Follow-up during March 2008 CommitFest
> 
> On Thu, 2007-06-07 at 21:53 +0100, Simon Riggs wrote:
> > On Sat, 2007-03-31 at 00:51 +0200, Florian G. Pflug wrote:

> > - pg_stop_backup() will wait until the WAL file that ends the backup is
> > safely archived, even if a failure to archive occurs. This is a change
> > to current behaviour, but since it implements the originally *expected*
> > behaviour IMHO it should be the default.
> 
> The most straightforward thing is to make pg_stop_backup() wait as
> described above.
> 
> If people want it to timeout, they can use a statement_timeout as
> suggested by Florian.
> 
> This can be implemented by having the function poll in an infinite loop
> for archive_status/LOG.done. Also, as Florian suggests, we should have
> it output a WARNING message every 60 seconds.
> 
> I'll write a patch now.

Patch to implement waiting pg_stop_backup(). 

Tested and ready to apply, includes docs.

-- 
  Simon Riggs
  2ndQuadrant  http://www.2ndQuadrant.com 

  PostgreSQL UK 2008 Conference: http://www.postgresql.org.uk
Index: doc/src/sgml/backup.sgml
===
RCS file: /home/sriggs/pg/REPOSITORY/pgsql/doc/src/sgml/backup.sgml,v
retrieving revision 2.116
diff -c -r2.116 backup.sgml
*** doc/src/sgml/backup.sgml	28 Mar 2008 15:00:28 -	2.116
--- doc/src/sgml/backup.sgml	31 Mar 2008 14:11:59 -
***
*** 761,772 
  
   Once the WAL segment files used during the backup are archived, you are
   done.  The file identified by pg_stop_backup's result is
!  the last segment that needs to be archived to complete the backup.
   Archival of these files will happen automatically, since you have
   already configured archive_command. In many cases, this
   happens fairly quickly, but you are advised to monitor your archival
!  system to ensure this has taken place so that you can be certain you
!  have a complete backup.
  
 

--- 761,779 
  
   Once the WAL segment files used during the backup are archived, you are
   done.  The file identified by pg_stop_backup's result is
!  the last segment that is required to form a complete set of backup files. 
!  pg_stop_backup does not return until the last segment has
!  been archived. 
   Archival of these files will happen automatically, since you have
   already configured archive_command. In many cases, this
   happens fairly quickly, but you are advised to monitor your archival
!  system to ensure there is no delay.
!  If the archival process has fallen significantly behind
!  because of failures of the archive command then we will keep waiting
!  and retrying until the archive succeeds and the backup is complete.
!  If you wish to place a time limit on the execution of 
!  pg_stop_backup then you should set an appropriate
!  statement_timeout.
  
 

***
*** 1044,1050 
 
   
The stop point must be after the ending time of the base backup, i.e.,
!   the time of pg_stop_backup.  You cannot use a base backup
to recover to a time when that backup was still going on.  (To
recover to such a time, you must go back to your previous base backup
and roll forward from there.)
--- 1051,1057 
 
   
The stop point must be after the ending time of the base backup, i.e.,
!   the end time of pg_stop_backup.  You cannot use a base backup
to recover to a time when that backup was still going on.  (To
recover to such a time, you must go back to your previous base backup
and roll forward from there.)
***
*** 1322,1327 
--- 1329,1335 
After the backup the switch file is removed. Archived WAL files are
then added to the backup so that both base backup and all required
WAL files are part of the same tar file.
+   Please remember to add error handling to your backup scripts.
   
  
  
Index: src/backend/access/transam/xlog.c
===
RCS file: /home/sriggs/pg/REPOSITORY/pgsql/src/backend/access/transam/xlog.c,v
retrieving revision 1.295
diff -c -r1.295 xlog.c
*** src/backend/access/transam/xlog.c	25 Mar 2008 22:42:42 -	1.295
--- src/backend/access/transam/xlog.c	1 Apr 2008 16:08:07 -
***
*** 382,388 
  
  static void XLogArchiveNotify(const char *xlog);
  static void XLogArchiveNotifySeg(uint32 log, uint32 seg);
! static bool XLogArchiveCheckDone(const char *xlog);
  static void XLogArchiveCleanup(const char *xlog);
  static void readRecoveryCommandFile(void);
  static void exitArchiveRecovery(TimeLineID endTLI,
--- 382,388 
  
  static void XLogArchiveNotify(const char *xlog);
  static void XLogArchiveNotifySeg(uint32 log, uint32 seg);
! static bool XLogArchiveCheck