backup: allow to use delete-wal without delete-expired(in accordance with documentation)

Author: gsmolk

src/backup.c

@@ -855,7 +855,7 @@ do_backup(time_t start_time)
 	 * After successfil backup completion remove backups
 	 * which are expired according to retention policies
 	 */
-	if (delete_expired)
+	if (delete_expired || delete_wal)
 		do_retention_purge();
 
 	return 0;

src/delete.c

@@ -134,15 +134,19 @@ do_retention_purge(void)
 	bool		keep_next_backup = true;	/* Do not delete first full backup */
 	bool		backup_deleted = false;		/* At least one backup was deleted */
 
-	if (retention_redundancy > 0)
-		elog(LOG, "REDUNDANCY=%u", retention_redundancy);
-	if (retention_window > 0)
-		elog(LOG, "WINDOW=%u", retention_window);
-
-	if (retention_redundancy == 0 && retention_window == 0 && !delete_wal)
+	if (delete_expired)
 	{
-		elog(WARNING, "Retention policy is not set");
-		return 0;
+		if (retention_redundancy > 0)
+			elog(LOG, "REDUNDANCY=%u", retention_redundancy);
+		if (retention_window > 0)
+			elog(LOG, "WINDOW=%u", retention_window);
+
+		if (retention_redundancy == 0 && retention_window == 0)
+		{
+			elog(WARNING, "Retention policy is not set");
+			if (!delete_wal)
+				return 0;
+		}
 	}
 
 	/* Get exclusive lock of backup catalog */
@@ -157,52 +161,67 @@ do_retention_purge(void)
 	}
 
 	/* Find target backups to be deleted */
-	backup_num = 0;
-	for (i = 0; i < parray_num(backup_list); i++)
+	if (delete_expired && (retention_redundancy > 0 || retention_window > 0))
 	{
-		pgBackup   *backup = (pgBackup *) parray_get(backup_list, i);
-		uint32		backup_num_evaluate = backup_num;
-
-		/* Consider only validated and correct backups */
-		if (backup->status != BACKUP_STATUS_OK)
-			continue;
-
-		/*
-		 * When a validate full backup was found, we can delete the
-		 * backup that is older than it using the number of generations.
-		 */
-		if (backup->backup_mode == BACKUP_MODE_FULL)
-			backup_num++;
-
-		/* Evaluate if this backup is eligible for removal */
-		if (keep_next_backup ||
-			backup_num_evaluate + 1 <= retention_redundancy ||
-			(retention_window > 0 && backup->recovery_time >= days_threshold))
+		backup_num = 0;
+		for (i = 0; i < parray_num(backup_list); i++)
 		{
-			/* Save LSN and Timeline to remove unnecessary WAL segments */
-			oldest_lsn = backup->start_lsn;
-			oldest_tli = backup->tli;
+			pgBackup   *backup = (pgBackup *) parray_get(backup_list, i);
+			uint32		backup_num_evaluate = backup_num;
 
-			/* Save parent backup of this incremental backup */
-			if (backup->backup_mode != BACKUP_MODE_FULL)
-				keep_next_backup = true;
+			/* Consider only validated and correct backups */
+			if (backup->status != BACKUP_STATUS_OK)
+				continue;
 			/*
-			 * Previous incremental backup was kept or this is first backup
-			 * so do not delete this backup.
+			 * When a validate full backup was found, we can delete the
+			 * backup that is older than it using the number of generations.
 			 */
-			else
-				keep_next_backup = false;
+			if (backup->backup_mode == BACKUP_MODE_FULL)
+				backup_num++;
 
-			continue;
+			/* Evaluateretention_redundancy if this backup is eligible for removal */
+			if (keep_next_backup ||
+				retention_redundancy >= backup_num_evaluate + 1 ||
+				(retention_window > 0 && backup->recovery_time >= days_threshold))
+			{
+				/* Save LSN and Timeline to remove unnecessary WAL segments */
+				oldest_lsn = backup->start_lsn;
+				oldest_tli = backup->tli;
+
+				/* Save parent backup of this incremental backup */
+				if (backup->backup_mode != BACKUP_MODE_FULL)
+					keep_next_backup = true;
+				/*
+				 * Previous incremental backup was kept or this is first backup
+				 * so do not delete this backup.
+				 */
+				else
+					keep_next_backup = false;
+
+				continue;
+			}
+			/* Delete backup and update status to DELETED */
+			pgBackupDeleteFiles(backup);
+			backup_deleted = true;
 		}
+	}
 
-		/* Delete backup and update status to DELETED */
-		pgBackupDeleteFiles(backup);
-		backup_deleted = true;
+	/*
+	 * If oldest_lsn wasn`t set in prevous step
+	 * get oldest backup LSN and TLI for WAL purging
+	 */
+	if (delete_wal && (XLogRecPtrIsInvalid(oldest_lsn)))
+	{
+		pgBackup   *backup = (pgBackup *) parray_get(backup_list, parray_num(backup_list) - 1);
+		oldest_lsn = backup->start_lsn;
+		oldest_tli = backup->tli;
 	}
 
 	/* Purge WAL files */
-	delete_walfiles(oldest_lsn, oldest_tli);
+	if (delete_wal)
+	{
+		delete_walfiles(oldest_lsn, oldest_tli);
+	}
 
 	/* Cleanup */
 	parray_walk(backup_list, pgBackupFree);
@@ -257,7 +276,7 @@ pgBackupDeleteFiles(pgBackup *backup)
 		pgFile	   *file = (pgFile *) parray_get(files, i);
 
 		/* print progress */
-		elog(LOG, "delete file(%zd/%lu) \"%s\"", i + 1,
+		elog(VERBOSE, "delete file(%zd/%lu) \"%s\"", i + 1,
 				(unsigned long) parray_num(files), file->path);
 
 		if (remove(file->path))

src/pg_probackup.c

@@ -114,13 +114,14 @@ static pgut_option options[] =
 	{ 'f', 'b', "backup-mode",			opt_backup_mode,	SOURCE_CMDLINE },
 	{ 'b', 'C', "smooth-checkpoint",	&smooth_checkpoint,	SOURCE_CMDLINE },
 	{ 's', 'S', "slot",					&replication_slot,	SOURCE_CMDLINE },
-	{ 'u', 11, "archive-timeout",		&archive_timeout,	SOURCE_CMDLINE },
-	{ 'b', 12, "delete-expired",		&delete_expired,	SOURCE_CMDLINE },
-	{ 's', 13, "master-db",				&master_db,			SOURCE_CMDLINE, },
-	{ 's', 14, "master-host",			&master_host,		SOURCE_CMDLINE, },
-	{ 's', 15, "master-port",			&master_port,		SOURCE_CMDLINE, },
-	{ 's', 16, "master-user",			&master_user,		SOURCE_CMDLINE, },
-	{ 'u', 17, "replica-timeout",		&replica_timeout,	SOURCE_CMDLINE,	SOURCE_DEFAULT,	OPTION_UNIT_S },
+	{ 'u', 11, "archive-timeout",		&archive_timeout,	SOURCE_CMDLINE, SOURCE_DEFAULT,	OPTION_UNIT_S },
+	{ 'b', 12, "delete-wal",			&delete_wal,		SOURCE_CMDLINE },
+	{ 'b', 13, "delete-expired",		&delete_expired,	SOURCE_CMDLINE },
+	{ 's', 14, "master-db",				&master_db,			SOURCE_CMDLINE, },
+	{ 's', 15, "master-host",			&master_host,		SOURCE_CMDLINE, },
+	{ 's', 16, "master-port",			&master_port,		SOURCE_CMDLINE, },
+	{ 's', 17, "master-user",			&master_user,		SOURCE_CMDLINE, },
+	{ 'u', 18, "replica-timeout",		&replica_timeout,	SOURCE_CMDLINE,	SOURCE_DEFAULT,	OPTION_UNIT_S },
 	/* TODO not completed feature. Make it unavailiable from user level
 	 { 'b', 18, "remote",				&is_remote_backup,	SOURCE_CMDLINE, }, */
 	/* restore options */
@@ -457,6 +458,8 @@ main(int argc, char *argv[])
 				elog(ERROR, "You cannot specify --delete-expired and --backup-id options together");
 			if (!delete_expired && !delete_wal && !backup_id_string_param)
 				elog(ERROR, "You must specify at least one of the delete options: --expired |--wal |--backup_id");
+			if (delete_wal && !delete_expired && !backup_id_string_param)
+				return do_retention_purge();
 			if (delete_expired)
 				return do_retention_purge();
 			else