We have the TODO item:
* Remove wal_files postgresql.conf option because WAL files are now recycled
The following patch completes this item. It also makes the WAL
documentation a lot easier to understand. ;-)
--
Bruce Momjian | http://candle.pha.pa.us
[EMAIL PROTECTED] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
Index: doc/src/sgml/runtime.sgml
===================================================================
RCS file: /cvsroot/pgsql-server/doc/src/sgml/runtime.sgml,v
retrieving revision 1.128
diff -c -c -r1.128 runtime.sgml
*** doc/src/sgml/runtime.sgml 29 Aug 2002 19:53:58 -0000 1.128
--- doc/src/sgml/runtime.sgml 30 Aug 2002 03:46:18 -0000
***************
*** 1949,1965 ****
</varlistentry>
<varlistentry>
- <term><varname>WAL_FILES</varname> (<type>integer</type>)</term>
- <listitem>
- <para>
- Number of log files that are created in advance at checkpoint
- time. This option can only be set at server start or in the
- <filename>postgresql.conf</filename> file.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
<term><varname>WAL_SYNC_METHOD</varname> (<type>string</type>)</term>
<listitem>
<para>
--- 1949,1954 ----
Index: doc/src/sgml/wal.sgml
===================================================================
RCS file: /cvsroot/pgsql-server/doc/src/sgml/wal.sgml,v
retrieving revision 1.16
diff -c -c -r1.16 wal.sgml
*** doc/src/sgml/wal.sgml 5 Jul 2002 19:06:11 -0000 1.16
--- doc/src/sgml/wal.sgml 30 Aug 2002 03:46:18 -0000
***************
*** 276,284 ****
By default a new 16MB segment file is created only if more than 75% of
the current segment has been used. This is inadequate if the system
generates more than 4MB of log output between checkpoints.
- One can instruct the server to pre-create up to 64 log segments
- at checkpoint time by modifying the <varname>WAL_FILES</varname>
- configuration parameter.
</para>
<para>
--- 276,281 ----
***************
*** 306,325 ****
<para>
The number of 16MB segment files will always be at least
! <varname>WAL_FILES</varname> + 1, and will normally not exceed
! <varname>WAL_FILES</varname> + MAX(<varname>WAL_FILES</varname>,
! <varname>CHECKPOINT_SEGMENTS</varname>) + 1. This may be used to
! estimate space requirements for WAL. Ordinarily, when an old log
! segment files are no longer needed, they are recycled (renamed to
! become the next sequential future segments). If, due to a short-term
! peak of log output rate, there are more than
! <varname>WAL_FILES</varname> + MAX(<varname>WAL_FILES</varname>,
! <varname>CHECKPOINT_SEGMENTS</varname>) + 1 segment files, then
! unneeded segment files will be deleted instead of recycled until the
! system gets back under this limit. (If this happens on a regular
! basis, <varname>WAL_FILES</varname> should be increased to avoid it.
! Deleting log segments that will only have to be created again later
! is expensive and pointless.)
</para>
<para>
--- 303,316 ----
<para>
The number of 16MB segment files will always be at least
! 1, and will normally not exceed <varname>CHECKPOINT_SEGMENTS</varname>)
! + 1. This may be used to estimate space requirements for WAL.
! Ordinarily, when old log segment files are no longer needed,
! they are recycled (renamed to become the next sequential future
! segments). If, due to a short-term peak of log output rate, there
! are more than <varname>CHECKPOINT_SEGMENTS</varname>) + 1 segment files,
! the unneeded segment files will be deleted instead of recycled until the
! system gets back under this limit.
</para>
<para>
Index: src/backend/access/transam/xlog.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/access/transam/xlog.c,v
retrieving revision 1.102
diff -c -c -r1.102 xlog.c
*** src/backend/access/transam/xlog.c 17 Aug 2002 15:12:06 -0000 1.102
--- src/backend/access/transam/xlog.c 30 Aug 2002 03:46:21 -0000
***************
*** 87,93 ****
/* User-settable parameters */
int CheckPointSegments = 3;
int XLOGbuffers = 8;
- int XLOGfiles = 0; /* # of files to preallocate during
ckpt */
int XLOG_DEBUG = 0;
char *XLOG_sync_method = NULL;
const char XLOG_sync_method_default[] = DEFAULT_SYNC_METHOD_STR;
--- 87,92 ----
***************
*** 97,103 ****
/*
* XLOGfileslop is used in the code as the allowed "fuzz" in the number of
* preallocated XLOG segments --- we try to have at least XLOGfiles advance
! * segments but no more than XLOGfiles+XLOGfileslop segments. This could
* be made a separate GUC variable, but at present I think it's sufficient
* to hardwire it as 2*CheckPointSegments+1. Under normal conditions, a
* checkpoint will free no more than 2*CheckPointSegments log segments, and
--- 96,102 ----
/*
* XLOGfileslop is used in the code as the allowed "fuzz" in the number of
* preallocated XLOG segments --- we try to have at least XLOGfiles advance
! * segments but no more than XLOGfileslop segments. This could
* be made a separate GUC variable, but at present I think it's sufficient
* to hardwire it as 2*CheckPointSegments+1. Under normal conditions, a
* checkpoint will free no more than 2*CheckPointSegments log segments, and
***************
*** 1422,1428 ****
* ours to pre-create a future log segment.
*/
if (!InstallXLogFileSegment(log, seg, tmppath,
! *use_existent,
XLOGfiles + XLOGfileslop,
use_lock))
{
/* No need for any more future segments... */
--- 1421,1427 ----
* ours to pre-create a future log segment.
*/
if (!InstallXLogFileSegment(log, seg, tmppath,
! *use_existent,
XLOGfileslop,
use_lock))
{
/* No need for any more future segments... */
***************
*** 1568,1587 ****
uint32 _logSeg;
int lf;
bool use_existent;
- int i;
XLByteToPrevSeg(endptr, _logId, _logSeg);
! if (XLOGfiles > 0)
! {
! for (i = 1; i <= XLOGfiles; i++)
! {
! NextLogSeg(_logId, _logSeg);
! use_existent = true;
! lf = XLogFileInit(_logId, _logSeg, &use_existent, true);
! close(lf);
! }
! }
! else if ((endptr.xrecoff - 1) % XLogSegSize >=
(uint32) (0.75 * XLogSegSize))
{
NextLogSeg(_logId, _logSeg);
--- 1567,1575 ----
uint32 _logSeg;
int lf;
bool use_existent;
XLByteToPrevSeg(endptr, _logId, _logSeg);
! if ((endptr.xrecoff - 1) % XLogSegSize >=
(uint32) (0.75 * XLogSegSize))
{
NextLogSeg(_logId, _logSeg);
***************
*** 1635,1645 ****
/*
* Before deleting the file, see if it can be recycled
as
* a future log segment. We allow recycling segments
up
! * to XLOGfiles + XLOGfileslop segments beyond the
current
* XLOG location.
*/
if (InstallXLogFileSegment(endlogId, endlogSeg, path,
!
true, XLOGfiles + XLOGfileslop,
true))
{
elog(LOG, "recycled transaction log file %s",
--- 1623,1633 ----
/*
* Before deleting the file, see if it can be recycled
as
* a future log segment. We allow recycling segments
up
! * to XLOGfileslop segments beyond the current
* XLOG location.
*/
if (InstallXLogFileSegment(endlogId, endlogSeg, path,
!
true, XLOGfileslop,
true))
{
elog(LOG, "recycled transaction log file %s",
Index: src/backend/utils/misc/guc.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/utils/misc/guc.c,v
retrieving revision 1.87
diff -c -c -r1.87 guc.c
*** src/backend/utils/misc/guc.c 29 Aug 2002 21:02:12 -0000 1.87
--- src/backend/utils/misc/guc.c 30 Aug 2002 03:46:23 -0000
***************
*** 641,651 ****
},
{
- { "wal_files", PGC_SIGHUP }, &XLOGfiles,
- 0, 0, 64, NULL, NULL
- },
-
- {
{ "wal_debug", PGC_SUSET }, &XLOG_DEBUG,
0, 0, 16, NULL, NULL
},
--- 641,646 ----
Index: src/include/access/xlog.h
===================================================================
RCS file: /cvsroot/pgsql-server/src/include/access/xlog.h,v
retrieving revision 1.35
diff -c -c -r1.35 xlog.h
*** src/include/access/xlog.h 17 Aug 2002 15:12:07 -0000 1.35
--- src/include/access/xlog.h 30 Aug 2002 03:46:23 -0000
***************
*** 185,191 ****
/* these variables are GUC parameters related to XLOG */
extern int CheckPointSegments;
extern int XLOGbuffers;
- extern int XLOGfiles;
extern int XLOG_DEBUG;
extern char *XLOG_sync_method;
extern const char XLOG_sync_method_default[];
--- 185,190 ----
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