On Wed, 2009-05-13 at 21:43 +0100, Simon Riggs wrote:
> On Wed, 2009-05-13 at 21:26 +0300, Heikki Linnakangas wrote:
>
> > This whole thing can be considered to be a new feature.
>
> recovery.conf will contain a new optional parameter:
>
> recovery_end_command (string)
Implemented.
Some possibility of re-factoring in calc of %r, though that has not been
done to ensure code clarity and avoid need for retesting other aspects
of recovery at this stage of beta.
--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support
Index: doc/src/sgml/backup.sgml
===================================================================
RCS file: /home/sriggs/pg/REPOSITORY/pgsql/doc/src/sgml/backup.sgml,v
retrieving revision 2.125
diff -c -r2.125 backup.sgml
*** doc/src/sgml/backup.sgml 27 Apr 2009 16:27:35 -0000 2.125
--- doc/src/sgml/backup.sgml 14 May 2009 15:14:35 -0000
***************
*** 1126,1131 ****
--- 1126,1154 ----
</listitem>
</varlistentry>
+ <varlistentry id="recovery-end-command" xreflabel="recovery_end_command">
+ <term><varname>recovery_end_command</varname> (<type>string</type>)</term>
+ <listitem>
+ <para>
+ This parameter specifies a shell command that will be executed once only
+ at the end of recovery. This parameter is optional. The purpose of the
+ recovery_end_command is to provide a mechanism for cleanup following
+ replication or recovery.
+ Any <literal>%r</> is replaced by the name of the file
+ containing the last valid restart point. That is the earliest file that
+ must be kept to allow a restore to be restartable, so this information
+ can be used to truncate the archive to just the minimum required to
+ support restart of the current restore. <literal>%r</> would only be
+ used in a warm-standby configuration (see <xref linkend="warm-standby">).
+ Write <literal>%%</> to embed an actual <literal>%</> character
+ in the command.
+ If the command returns a non-zero exit status then a WARNING log
+ message will be written, unless signalled in which case we return
+ a FATAL error.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="recovery-target-time" xreflabel="recovery_target_time">
<term><varname>recovery_target_time</varname>
(<type>timestamp</type>)
Index: doc/src/sgml/pgstandby.sgml
===================================================================
RCS file: /home/sriggs/pg/REPOSITORY/pgsql/doc/src/sgml/pgstandby.sgml,v
retrieving revision 2.7
diff -c -r2.7 pgstandby.sgml
*** doc/src/sgml/pgstandby.sgml 27 Feb 2009 09:30:21 -0000 2.7
--- doc/src/sgml/pgstandby.sgml 14 May 2009 15:33:18 -0000
***************
*** 210,215 ****
--- 210,216 ----
archive_command = 'cp %p .../archive/%f'
restore_command = 'pg_standby -l -d -s 2 -t /tmp/pgsql.trigger.5442 .../archive %f %p %r 2>>standby.log'
+ recovery_end_command = 'rm /tmp/pgsql.trigger.5442'
</programlisting>
<para>
where the archive directory is physically located on the standby server,
***************
*** 241,246 ****
--- 242,252 ----
</listitem>
<listitem>
<para>
+ remove the trigger file when recovery ends
+ </para>
+ </listitem>
+ <listitem>
+ <para>
remove no-longer-needed files from the archive directory
</para>
</listitem>
Index: src/backend/access/transam/xlog.c
===================================================================
RCS file: /home/sriggs/pg/REPOSITORY/pgsql/src/backend/access/transam/xlog.c,v
retrieving revision 1.337
diff -c -r1.337 xlog.c
*** src/backend/access/transam/xlog.c 7 May 2009 11:25:25 -0000 1.337
--- src/backend/access/transam/xlog.c 14 May 2009 15:19:41 -0000
***************
*** 147,152 ****
--- 147,153 ----
/* options taken from recovery.conf */
static char *recoveryRestoreCommand = NULL;
+ static char *recoveryEndCommand = NULL;
static bool recoveryTarget = false;
static bool recoveryTargetExact = false;
static bool recoveryTargetInclusive = true;
***************
*** 463,468 ****
--- 464,470 ----
static void XLogFileClose(void);
static bool RestoreArchivedFile(char *path, const char *xlogfname,
const char *recovername, off_t expectedSize);
+ static void ExecuteRecoveryEndCommand(void);
static void PreallocXlogFiles(XLogRecPtr endptr);
static void RemoveOldXlogFiles(uint32 log, uint32 seg, XLogRecPtr endptr);
static void ValidateXLOGDirectoryStructure(void);
***************
*** 2850,2855 ****
--- 2852,2965 ----
}
/*
+ * Attempt to execute the recovery_end_command.
+ */
+ static void
+ ExecuteRecoveryEndCommand(void)
+ {
+ char xlogRecoveryEndCmd[MAXPGPATH];
+ char lastRestartPointFname[MAXPGPATH];
+ char *dp;
+ char *endp;
+ const char *sp;
+ int rc;
+ bool signaled;
+ uint32 restartLog;
+ uint32 restartSeg;
+
+ Assert(recoveryEndCommand);
+
+ /*
+ * Calculate the archive file cutoff point for use during log shipping
+ * replication. All files earlier than this point can be deleted
+ * from the archive, though there is no requirement to do so.
+ *
+ * We initialise this with the filename of an InvalidXLogRecPtr, which
+ * will prevent the deletion of any WAL files from the archive
+ * because of the alphabetic sorting property of WAL filenames.
+ *
+ * Once we have successfully located the redo pointer of the checkpoint
+ * from which we start recovery we never request a file prior to the redo
+ * pointer of the last restartpoint. When redo begins we know that we
+ * have successfully located it, so there is no need for additional
+ * status flags to signify the point when we can begin deleting WAL files
+ * from the archive.
+ */
+ if (InRedo)
+ {
+ XLByteToSeg(ControlFile->checkPointCopy.redo,
+ restartLog, restartSeg);
+ XLogFileName(lastRestartPointFname,
+ ControlFile->checkPointCopy.ThisTimeLineID,
+ restartLog, restartSeg);
+ }
+ else
+ XLogFileName(lastRestartPointFname, 0, 0, 0);
+
+ /*
+ * construct the command to be executed
+ */
+ dp = xlogRecoveryEndCmd;
+ endp = xlogRecoveryEndCmd + MAXPGPATH - 1;
+ *endp = '\0';
+
+ for (sp = recoveryEndCommand; *sp; sp++)
+ {
+ if (*sp == '%')
+ {
+ switch (sp[1])
+ {
+ case 'r':
+ /* %r: filename of last restartpoint */
+ sp++;
+ StrNCpy(dp, lastRestartPointFname, endp - dp);
+ dp += strlen(dp);
+ break;
+ case '%':
+ /* convert %% to a single % */
+ sp++;
+ if (dp < endp)
+ *dp++ = *sp;
+ break;
+ default:
+ /* otherwise treat the % as not special */
+ if (dp < endp)
+ *dp++ = *sp;
+ break;
+ }
+ }
+ else
+ {
+ if (dp < endp)
+ *dp++ = *sp;
+ }
+ }
+ *dp = '\0';
+
+ ereport(DEBUG3,
+ (errmsg_internal("executing recovery end command \"%s\"",
+ xlogRecoveryEndCmd)));
+
+ /*
+ * Copy xlog from archival storage to XLOGDIR
+ */
+ rc = system(xlogRecoveryEndCmd);
+ if (rc != 0)
+ {
+ /*
+ * If the failure was due to any sort of signal, it's best to punt and
+ * abort recovery. See also detailed comments on signals in
+ * RestoreArchivedFile().
+ */
+ signaled = WIFSIGNALED(rc) || WEXITSTATUS(rc) > 125;
+
+ ereport(signaled ? FATAL : WARNING,
+ (errmsg("recovery_end_command \"%s\": return code %d",
+ xlogRecoveryEndCmd, rc)));
+ }
+ }
+
+ /*
* Preallocate log files beyond the specified log endpoint.
*
* XXX this is currently extremely conservative, since it forces only one
***************
*** 4664,4669 ****
--- 4774,4786 ----
(errmsg("restore_command = '%s'",
recoveryRestoreCommand)));
}
+ else if (strcmp(tok1, "recovery_end_command") == 0)
+ {
+ recoveryEndCommand = pstrdup(tok2);
+ ereport(LOG,
+ (errmsg("recovery_end_command = '%s'",
+ recoveryEndCommand)));
+ }
else if (strcmp(tok1, "recovery_target_timeline") == 0)
{
rtliGiven = true;
***************
*** 5622,5627 ****
--- 5739,5747 ----
* allows some extra error checking in xlog_redo.
*/
CreateCheckPoint(CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_IMMEDIATE);
+
+ if (recoveryEndCommand)
+ ExecuteRecoveryEndCommand();
}
/*
--
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