Remove standby.signal if the data is backuped from standby (#158)

* Remove standby.signal if the data is backuped from standby Although pg_rman doesn't treat the backup as restoring on standby automatically, it remains standby.signal. So, this patch removes the file. * update for review comments
ossc-db · Apr 30, 2021 · dbf9458 · dbf9458
1 parent 95281f7
commit dbf9458
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Showing 3 changed files with 143 additions and 15 deletions.
diff --git a/expected/backup_from_standby.out b/expected/backup_from_standby.out
@@ -12,3 +12,26 @@
 0
 0
 0
+
+###### BACKUP COMMAND FROM STANDBY SERVER TEST-0003 ######
+0
+0
+0
+
+###### must be primary even if the recovery target is latest ######
+ pg_is_in_recovery 
+-------------------
+ f
+(1 row)
+
+###### BACKUP COMMAND FROM STANDBY SERVER TEST-0004 ######
+0
+0
+0
+
+###### must be standby and synchronized with the primary server ######
+  status   
+-----------
+ streaming
+(1 row)
+
diff --git a/restore.c b/restore.c
@@ -29,6 +29,7 @@ static void add_recovery_related_options(const char *target_time,
 										 TimeLineID target_tli,
 										 bool target_tli_latest);
 static void create_recovery_signal(void);
+static void remove_standby_signal(void);
 
 static pgRecoveryTarget *checkIfCreateRecoveryConf(const char *target_time,
 								 const char *target_xid,
@@ -378,6 +379,12 @@ do_restore(const char *target_time,
 	/* Create recovery.signal file */
 	create_recovery_signal();
 
+	/*
+	 * Remove if standby.signal file exists because pg_rman doesn’t treat
+	 * the backup as restoring on standby automatically now.
+	 */
+	remove_standby_signal();
+
 	/* release catalog lock */
 	catalog_unlock();
 
@@ -799,6 +806,38 @@ create_recovery_signal(void)
 	}
 }
 
+static void
+remove_standby_signal(void)
+{
+	struct stat stat_buf;
+	char path[MAXPGPATH];
+
+	if (verbose && !check)
+		printf(_("----------------------------------------\n"));
+
+	elog(INFO, _("removing standby.signal if exists to restore as primary"));
+
+	if (!check)
+	{
+		snprintf(path, lengthof(path), "%s/standby.signal", pgdata);
+
+		if (stat(path, &stat_buf) == 0)
+		{
+			if (remove(path))
+			{
+				ereport(ERROR,
+					(errcode(ERROR_SYSTEM),
+					 errmsg("could not remove \"%s\": %s", path,
+						strerror(errno))));
+			}
+			ereport(INFO,
+				(errmsg("removed standby.signal"),
+				 errhint("if you want to start as standby, additional manual"
+						"setups to make standby.signal and so on are required")));
+		}
+	}
+}
+
 static void
 backup_online_files(bool re_recovery)
 {

diff --git a/sql/backup_from_standby.sh b/sql/backup_from_standby.sh
@@ -150,17 +150,43 @@ EOF
 	pg_ctl -D ${SBYDATA_PATH} start -w -t 600 > /dev/null 2>&1
 }
 
+function load_with_pgbench
+{
+	pgbench -p ${TEST_PGPORT} -T ${DURATION} -d pgbench > /dev/null 2>&1
+}
+
+function full_backup_from_standby
+{
+	pg_rman backup -B ${BACKUP_PATH} -b full -Z -p ${TEST_PGPORT} -d postgres -D ${SBYDATA_PATH} --standby-host=localhost --standby-port=${TEST_SBYPGPORT} --quiet;echo $?
+	pg_rman validate -B ${BACKUP_PATH} --quiet; echo $?
+}
+
+function incremental_backup_from_standby
+{
+	pg_rman backup -B ${BACKUP_PATH} -b incremental -Z -p ${TEST_PGPORT} -d postgres -D ${SBYDATA_PATH} --standby-host=localhost --standby-port=${TEST_SBYPGPORT} --quiet;echo $?
+	pg_rman validate -B ${BACKUP_PATH} --quiet; echo $?
+}
+
+function get_database_data_from_primary
+{
+	psql -p ${TEST_PGPORT} --no-psqlrc -d pgbench -c "SELECT * FROM pgbench_branches;"
+}
+
+function get_database_data_from_standby
+{
+	psql -p ${TEST_SBYPGPORT} --no-psqlrc -d pgbench -c "SELECT * FROM pgbench_branches;"
+}
+
 init_backup
 setup_standby
 init_catalog
 echo '###### BACKUP COMMAND FROM STANDBY SERVER TEST-0001 ######'
 echo '###### full backup mode ######'
-pgbench -p ${TEST_PGPORT} -T ${DURATION} -d pgbench > /dev/null 2>&1
-psql -p ${TEST_PGPORT} --no-psqlrc -d pgbench -c "SELECT * FROM pgbench_branches;" > ${TEST_BASE}/TEST-0001-before.out
-pg_rman backup -B ${BACKUP_PATH} -b full -Z -p ${TEST_PGPORT} -d postgres -D ${SBYDATA_PATH} --standby-host=localhost --standby-port=${TEST_SBYPGPORT} --quiet;echo $?
-pg_rman validate -B ${BACKUP_PATH} --quiet; echo $?
+load_with_pgbench
+get_database_data_from_primary > ${TEST_BASE}/TEST-0001-before.out
+full_backup_from_standby
 TARGET_XID=`psql -p ${TEST_PGPORT} --no-psqlrc -d pgbench -tAq -c "INSERT INTO pgbench_history VALUES (1) RETURNING(xmin);"`
-pgbench -p ${TEST_PGPORT} -T ${DURATION} -d pgbench > /dev/null 2>&1
+load_with_pgbench
 pg_ctl stop -m immediate -D ${PGDATA_PATH} > /dev/null 2>&1
 cp ${PGDATA_PATH}/postgresql.conf ${TEST_BASE}/postgresql.conf
 sleep 1
@@ -173,7 +199,7 @@ ${BACKUP_RESTORE_COMMAND}
 ${BACKUP_TARGET_XID_COMMAND}
 EOF
 pg_ctl start -w -t 600 -D ${PGDATA_PATH} > /dev/null 2>&1
-psql -p ${TEST_PGPORT} --no-psqlrc -d pgbench -c "SELECT * FROM pgbench_branches;" > ${TEST_BASE}/TEST-0001-after.out
+get_database_data_from_primary > ${TEST_BASE}/TEST-0001-after.out
 diff ${TEST_BASE}/TEST-0001-before.out ${TEST_BASE}/TEST-0001-after.out
 echo ''
 
@@ -182,15 +208,13 @@ setup_standby
 init_catalog
 echo '###### BACKUP COMMAND FROM STANDBY SERVER TEST-0002 ######'
 echo '###### full + incremental backup mode ######'
-pgbench -p ${TEST_PGPORT} -d pgbench > /dev/null 2>&1
-pg_rman backup -B ${BACKUP_PATH} -b full -Z -p ${TEST_PGPORT} -d postgres -D ${SBYDATA_PATH} --standby-host=localhost --standby-port=${TEST_SBYPGPORT} --quiet;echo $?
-pg_rman validate -B ${BACKUP_PATH} --quiet; echo $?
-pgbench -p ${TEST_PGPORT} -T ${DURATION} -d pgbench > /dev/null 2>&1
-pg_rman backup -B ${BACKUP_PATH} -b incremental -Z -p ${TEST_PGPORT} -d postgres -D ${SBYDATA_PATH} --standby-host=localhost --standby-port=${TEST_SBYPGPORT} --quiet;echo $?
-pg_rman validate -B ${BACKUP_PATH} --quiet; echo $?
-psql -p ${TEST_PGPORT} --no-psqlrc -d pgbench -c "SELECT * FROM pgbench_branches;" > ${TEST_BASE}/TEST-0002-before.out
+load_with_pgbench
+full_backup_from_standby
+load_with_pgbench
+incremental_backup_from_standby
+get_database_data_from_primary > ${TEST_BASE}/TEST-0002-before.out
 TARGET_XID=`psql -p ${TEST_PGPORT} --no-psqlrc -d pgbench -tAq -c "INSERT INTO pgbench_history VALUES (1) RETURNING(xmin);"`
-pgbench -p ${TEST_PGPORT} -T ${DURATION} pgbench > /dev/null 2>&1
+load_with_pgbench
 pg_ctl stop -m immediate -D ${PGDATA_PATH} > /dev/null 2>&1
 cp ${PGDATA_PATH}/postgresql.conf ${TEST_BASE}/postgresql.conf
 sleep 1
@@ -203,9 +227,51 @@ ${BACKUP_RESTORE_COMMAND}
 ${BACKUP_TARGET_XID_COMMAND}
 EOF
 pg_ctl start -w -t 600 -D ${PGDATA_PATH} > /dev/null 2>&1
-psql -p ${TEST_PGPORT} --no-psqlrc -d pgbench -c "SELECT * FROM pgbench_branches;" > ${TEST_BASE}/TEST-0002-after.out
+get_database_data_from_primary > ${TEST_BASE}/TEST-0002-after.out
 diff ${TEST_BASE}/TEST-0002-before.out ${TEST_BASE}/TEST-0002-after.out
+echo ''
+
+# check to start as primary (stand-alone) if the recovery target is latest
+init_backup
+setup_standby
+init_catalog
+echo '###### BACKUP COMMAND FROM STANDBY SERVER TEST-0003 ######'
+load_with_pgbench
+get_database_data_from_primary > ${TEST_BASE}/TEST-0003-before.out
+full_backup_from_standby
+# Don't load_with_pgbench again. It makes the *.out result difference because
+# restoring to the latest point using archived wal including the one generated
+# by the second load.
+pg_ctl stop -m immediate -D ${PGDATA_PATH} > /dev/null 2>&1
+pg_rman restore -B ${BACKUP_PATH} -D ${PGDATA_PATH} --quiet;echo $?
+sed -i -e "s/^port = .*$/port = ${TEST_PGPORT}/" ${PGDATA_PATH}/postgresql.conf
+pg_ctl start -w -t 600 -D ${PGDATA_PATH} > /dev/null 2>&1
+get_database_data_from_primary > ${TEST_BASE}/TEST-0003-after.out
+diff ${TEST_BASE}/TEST-0003-before.out ${TEST_BASE}/TEST-0003-after.out
+echo ''
+echo '###### must be primary even if the recovery target is latest ######'
+sleep 3  # wait until finishing recovery
+psql -p ${TEST_PGPORT} --no-psqlrc -d pgbench -c "SELECT pg_is_in_recovery();"
 
+# check to start as standby if a user configure it manually
+init_backup
+setup_standby
+init_catalog
+echo '###### BACKUP COMMAND FROM STANDBY SERVER TEST-0004 ######'
+load_with_pgbench
+full_backup_from_standby
+load_with_pgbench  # this data will be replicated after restoring
+get_database_data_from_primary > ${TEST_BASE}/TEST-0004-before.out
+pg_ctl stop -m immediate -D ${SBYDATA_PATH} > /dev/null 2>&1
+pg_rman restore -B ${BACKUP_PATH} -D ${SBYDATA_PATH} --quiet;echo $?
+touch ${SBYDATA_PATH}/standby.signal  # configure for standby server
+pg_ctl start -w -t 600 -D ${SBYDATA_PATH} > /dev/null 2>&1
+echo ''
+echo '###### must be standby and synchronized with the primary server ######'
+sleep 3  # wait until finishing to sync
+psql -p ${TEST_SBYPGPORT} --no-psqlrc -d pgbench -c "SELECT status FROM pg_stat_wal_receiver;"
+get_database_data_from_standby > ${TEST_BASE}/TEST-0004-after.out
+diff ${TEST_BASE}/TEST-0004-before.out ${TEST_BASE}/TEST-0004-after.out
 
 # clean up the temporal test data
 pg_ctl stop -m immediate -D ${PGDATA_PATH} > /dev/null 2>&1