Postgresql基於時間點恢復PITR案例(二)

一個朋友說參考了網址：http://www.mkyong.com/database/postgresql-point-in-time-recovery-incremental-backup/後作了一個基於時間點的數據庫恢復操做，可是失敗了。其過程大體以下： 
測試環境：vmware 8
os ：centos 5.7 (final)
PG: version 9.1.2

####如下是他的測試過程記錄

postgres=# create table testPITR1 as select * from pg_class, pg_description; 
SELECT 936936
postgres=# select * from current_timestamp(0);
timestamptz 
------------------------
2012-07-02 01:53:16-07
(1 row)

postgres=# select pg_start_backup('full_backup-testing_20120702');
pg_start_backup 
-----------------
0/60000020
(1 row)

postgres=# select pg_current_xlog_location();
pg_current_xlog_location 
--------------------------
0/600000B0
(1 row)

--打包數據文件 tar pgdata.tar ./pgdata

postgres=# select pg_stop_backup();
NOTICE: pg_stop_backup complete, all required WAL segments have been archived
pg_stop_backup 
----------------
0/60000168
(1 row)

postgres=# create table testPITR2 as select * from pg_class, pg_description;
SELECT 946764
postgres=# select * from current_timestamp(0);
timestamptz 
------------------------
2012-07-02 02:05:20-07
(1 row)


postgres=# create table testPITR3 as select * from pg_class, pg_description; 
SELECT 956592
postgres=# select * from current_timestamp(0);
timestamptz 
------------------------
2012-07-02 02:14:33-07
(1 row)

postgres=# create table testPITR4 as select * from pg_class, pg_description; 
SELECT 966420
postgres=# select * from current_timestamp(0);
timestamptz 
------------------------
2012-07-02 02:35:31-07
(1 row)

postgres=# \d
List of relations
Schema | Name | Type | Owner 
--------+-------------+-------+----------
public | tesk | table | postgres
public | test | table | postgres
public | testpitr1 | table | postgres
public | testpitr2 | table | postgres
public | testpitr3 | table | postgres
public | testpitr4 | table | postgres
(7 rows)

[postgres@localhost archive]$ pwd
/home/postgres/archive
[postgres@localhost archive]$ ls -lsh
total 1.1G
64M -rw-------. 1 postgres postgres 64M Jul 2 01:41 000000020000000000000013
64M -rw-------. 1 postgres postgres 64M Jul 2 01:52 000000020000000000000014
64M -rw-------. 1 postgres postgres 64M Jul 2 01:52 000000020000000000000015
64M -rw-------. 1 postgres postgres 64M Jul 2 01:52 000000020000000000000016
64M -rw-------. 1 postgres postgres 64M Jul 2 01:56 000000020000000000000017
64M -rw-------. 1 postgres postgres 64M Jul 2 02:04 000000020000000000000018
4.0K -rw-------. 1 postgres postgres 295 Jul 2 02:04 000000020000000000000018.00000020.backup
64M -rw-------. 1 postgres postgres 64M Jul 2 02:04 000000020000000000000019
64M -rw-------. 1 postgres postgres 64M Jul 2 02:05 00000002000000000000001A
64M -rw-------. 1 postgres postgres 64M Jul 2 02:05 00000002000000000000001B
64M -rw-------. 1 postgres postgres 64M Jul 2 02:07 00000002000000000000001C
64M -rw-------. 1 postgres postgres 64M Jul 2 02:07 00000002000000000000001D
64M -rw-------. 1 postgres postgres 64M Jul 2 02:07 00000002000000000000001E
64M -rw-------. 1 postgres postgres 64M Jul 2 02:07 00000002000000000000001F
64M -rw-------. 1 postgres postgres 64M Jul 2 02:35 000000020000000000000020
64M -rw-------. 1 postgres postgres 64M Jul 2 02:35 000000020000000000000021
64M -rw-------. 1 postgres postgres 64M Jul 2 02:35 000000020000000000000022
64M -rw-------. 1 postgres postgres 64M Jul 2 02:35 000000020000000000000023

將原來的PGDATA經過move名字改成pgdata_bad
[postgres@localhost pg_xlog]$ pwd
/database/pgdata_bad/pg_xlog
[postgres@localhost pg_xlog]$ ls -lsh
total 1.9G
64M -rw-------. 1 postgres postgres 64M Jun 14 22:33 00000001000000000000000C
64M -rw-------. 1 postgres postgres 64M Jun 14 22:33 00000001000000000000000D
64M -rw-------. 1 postgres postgres 64M Jun 14 21:05 00000001000000000000000E
64M -rw-------. 1 postgres postgres 64M Jun 14 22:05 00000001000000000000000F
64M -rw-------. 1 postgres postgres 64M Jun 15 03:40 00000002000000000000000D
64M -rw-------. 1 postgres postgres 64M Jun 15 03:46 00000002000000000000000E
64M -rw-------. 1 postgres postgres 64M Jun 15 03:51 00000002000000000000000F
64M -rw-------. 1 postgres postgres 64M Jun 15 04:23 000000020000000000000010
64M -rw-------. 1 postgres postgres 64M Jun 25 02:41 000000020000000000000011
64M -rw-------. 1 postgres postgres 64M Jun 30 01:24 000000020000000000000012
65M -rw-------. 1 postgres postgres 64M Jul 2 01:41 000000020000000000000013
64M -rw-------. 1 postgres postgres 64M Jul 2 01:52 000000020000000000000014
64M -rw-------. 1 postgres postgres 64M Jul 2 01:52 000000020000000000000015
64M -rw-------. 1 postgres postgres 64M Jul 2 01:52 000000020000000000000016
64M -rw-------. 1 postgres postgres 64M Jul 2 01:56 000000020000000000000017
64M -rw-------. 1 postgres postgres 64M Jul 2 02:04 000000020000000000000018
4.0K -rw-------. 1 postgres postgres 295 Jul 2 02:04 000000020000000000000018.00000020.backup
64M -rw-------. 1 postgres postgres 64M Jul 2 02:04 000000020000000000000019
65M -rw-------. 1 postgres postgres 64M Jul 2 02:05 00000002000000000000001A
64M -rw-------. 1 postgres postgres 64M Jul 2 02:05 00000002000000000000001B
64M -rw-------. 1 postgres postgres 64M Jul 2 02:07 00000002000000000000001C
64M -rw-------. 1 postgres postgres 64M Jul 2 02:07 00000002000000000000001D
64M -rw-------. 1 postgres postgres 64M Jul 2 02:07 00000002000000000000001E
64M -rw-------. 1 postgres postgres 64M Jul 2 02:07 00000002000000000000001F
64M -rw-------. 1 postgres postgres 64M Jul 2 02:35 000000020000000000000020
64M -rw-------. 1 postgres postgres 64M Jul 2 02:35 000000020000000000000021
65M -rw-------. 1 postgres postgres 64M Jul 2 02:35 000000020000000000000022
64M -rw-------. 1 postgres postgres 64M Jul 2 02:35 000000020000000000000023
64M -rw-------. 1 postgres postgres 64M Jul 2 02:37 000000020000000000000024
4.0K -rw-------. 1 postgres postgres 56 Jun 14 22:34 00000002.history
4.0K drwx------. 2 postgres postgres 4.0K Jul 2 02:35 archive_status
36M -rw-------. 1 postgres postgres 36M Jun 25 02:41 xlogtemp.2046
24M -rw-------. 1 postgres postgres 24M Jun 30 01:24 xlogtemp.2077

將以前打包備份的文件釋放到pgdata位置，並重建pg_xlog文件，而後啓動
# rm -rf pg_xlog
# mkdir -p pg_xlog/archive_status
這個時候啓動是正常的，PSQL能夠登陸進去

postgres=# \d
List of relations
Schema | Name | Type | Owner 
--------+-------------+-------+----------
public | tesk | table | postgres
public | test | table | postgres
public | testpitr1 | table | postgres
(4 rows)

由於沒有作恢復，因此是正常的。
而後關閉數據庫，設置recovery.conf文件
restore_command = 'cp /home/postgres/archive/%f %p'
recovery_target_time = '2012-07-02 02:10:31'
設置完了再啓動就報錯了，日誌以下：

[root@localhost pg_log]# more postgresql-2012-07-03_014309.csv
2012-07-03 01:43:09.701 PDT,,,7621,,4ff2b09d.1dc5,1,,2012-07-03 01:43:09 PDT,,0,LOG,00000,"database system was shut down at 2012-07-03 00:03:21 PDT",,,,,,,,,""
2012-07-03 01:43:09.764 PDT,,,7621,,4ff2b09d.1dc5,2,,2012-07-03 01:43:09 PDT,,0,LOG,00000,"starting point-in-time recovery to 2012-07-02 02:10:31-07",,,,,,,,,""
2012-07-03 01:43:14.177 PDT,,,7621,,4ff2b09d.1dc5,3,,2012-07-03 01:43:09 PDT,,0,LOG,00000,"restored log file ""000000020000000000000019"" from archive",,,,,,,,,""
2012-07-03 01:43:14.177 PDT,,,7621,,4ff2b09d.1dc5,4,,2012-07-03 01:43:09 PDT,,0,LOG,00000,"invalid resource manager ID in primary checkpoint record",,,,,,,,,""
2012-07-03 01:43:14.342 PDT,,,7621,,4ff2b09d.1dc5,5,,2012-07-03 01:43:09 PDT,,0,LOG,00000,"restored log file ""000000020000000000000018"" from archive",,,,,,,,,""
2012-07-03 01:43:14.342 PDT,,,7621,,4ff2b09d.1dc5,6,,2012-07-03 01:43:09 PDT,,0,LOG,00000,"invalid xl_info in secondary checkpoint record",,,,,,,,,""
2012-07-03 01:43:14.342 PDT,,,7621,,4ff2b09d.1dc5,7,,2012-07-03 01:43:09 PDT,,0,PANIC,XX000,"could not locate a valid checkpoint record",,,,,,,,,""
2012-07-03 01:43:18.500 PDT,,,7619,,4ff2b09c.1dc3,1,,2012-07-03 01:43:08 PDT,,0,LOG,00000,"startup process (PID 7621) was terminated by signal 6: Aborted",,,,,,,,,""
2012-07-03 01:43:18.500 PDT,,,7619,,4ff2b09c.1dc3,2,,2012-07-03 01:43:08 PDT,,0,LOG,00000,"aborting startup due to startup process failure",,,,,,,,,""

[root@localhost pg_log]# more postgresql-2012-07-03_014309.log
cp: cannot stat `/home/postgres/archive/00000002.history': No such file or directory

[root@localhost archive]# more 00000002.history 
1 00000001000000000000000D no recovery target specified

看了一下，/home/postgres/archive/00000002.history這個文件確實是沒有，就從老的備份文件裏面拷貝了一份過去，再啓動，.log文件沒有信息了，可是.csv文件報錯以下：

[root@localhost pg_log]# more postgresql-2012-07-03_014413.csv
2012-07-03 01:44:13.159 PDT,,,7647,,4ff2b0dd.1ddf,1,,2012-07-03 01:44:13 PDT,,0,LOG,00000,"database system was shut down at 2012-07-03 00:03:21 PDT",,,,,,,,,""
2012-07-03 01:44:13.168 PDT,,,7647,,4ff2b0dd.1ddf,2,,2012-07-03 01:44:13 PDT,,0,LOG,00000,"restored log file ""00000002.history"" from archive",,,,,,,,,""
2012-07-03 01:44:13.168 PDT,,,7647,,4ff2b0dd.1ddf,3,,2012-07-03 01:44:13 PDT,,0,LOG,00000,"starting point-in-time recovery to 2012-07-02 02:10:31-07",,,,,,,,,""
2012-07-03 01:44:13.300 PDT,,,7647,,4ff2b0dd.1ddf,4,,2012-07-03 01:44:13 PDT,,0,LOG,00000,"restored log file ""000000020000000000000019"" from archive",,,,,,,,,""
2012-07-03 01:44:13.300 PDT,,,7647,,4ff2b0dd.1ddf,5,,2012-07-03 01:44:13 PDT,,0,LOG,00000,"invalid resource manager ID in primary checkpoint record",,,,,,,,,""
2012-07-03 01:44:13.407 PDT,,,7647,,4ff2b0dd.1ddf,6,,2012-07-03 01:44:13 PDT,,0,LOG,00000,"restored log file ""000000020000000000000018"" from archive",,,,,,,,,""
2012-07-03 01:44:13.407 PDT,,,7647,,4ff2b0dd.1ddf,7,,2012-07-03 01:44:13 PDT,,0,LOG,00000,"invalid xl_info in secondary checkpoint record",,,,,,,,,""
2012-07-03 01:44:13.407 PDT,,,7647,,4ff2b0dd.1ddf,8,,2012-07-03 01:44:13 PDT,,0,PANIC,XX000,"could not locate a valid checkpoint record",,,,,,,,,""
2012-07-03 01:44:13.811 PDT,,,7645,,4ff2b0dc.1ddd,1,,2012-07-03 01:44:12 PDT,,0,LOG,00000,"startup process (PID 7647) was terminated by signal 6: Aborted",,,,,,,,,""
2012-07-03 01:44:13.811 PDT,,,7645,,4ff2b0dc.1ddd,2,,2012-07-03 01:44:12 PDT,,0,LOG,00000,"aborting startup due to startup process failure",,,,,,,,,""

最終的PG_CONTROLDATA信息以下：

[postgres@localhost pgdata]$ pg_controldata
pg_control version number: 903
Catalog version number: 201105231
Database system identifier: 5735970894348214195
Database cluster state: shut down
pg_control last modified: Tue 03 Jul 2012 12:03:21 AM PDT
Latest checkpoint location: 0/64000020
Prior checkpoint location: 0/60000140
Latest checkpoint's REDO location: 0/64000020
Latest checkpoint's TimeLineID: 2
Latest checkpoint's NextXID: 0/1859
Latest checkpoint's NextOID: 40985
Latest checkpoint's NextMultiXactId: 1
Latest checkpoint's NextMultiOffset: 0
Latest checkpoint's oldestXID: 1792
Latest checkpoint's oldestXID's DB: 1
Latest checkpoint's oldestActiveXID: 0
Time of latest checkpoint: Tue 03 Jul 2012 12:03:17 AM PDT
Minimum recovery ending location: 0/0
Backup start location: 0/0
Current wal_level setting: hot_standby
Current max_connections setting: 100
Current max_prepared_xacts setting: 0
Current max_locks_per_xact setting: 64
Maximum data alignment: 8
Database block size: 8192
Blocks per segment of large relation: 1048576
WAL block size: 65536
Bytes per WAL segment: 67108864
Maximum length of identifiers: 64
Maximum columns in an index: 32
Maximum size of a TOAST chunk: 1996
Date/time type storage: 64-bit integers
Float4 argument passing: by value
Float8 argument passing: by value

########說明##########
在上述恢復的過程當中，該DB被啓動了兩次，在第一次啓動的時候是沒有指定recovery.conf文件的，這裏有一個先後的順序問題，應該先配置recovery.conf，配置其恢復的時間點，而後啓動DB。啓動時已經有了一個check點了，這個時候再恢復到過去是不可能的，固然了，若是把recovery.conf中的recovery_target_time設置成比第一次啓動晚的時間點也是能夠的。 我本機的檢測過程以下：

[postgres@localhost pgdata]$ psql
psql (9.1.2)
Type "help" for help.

postgres=# select pg_current_xlog_location();
 pg_current_xlog_location 
--------------------------
 0/94000078
(1 row)

postgres=# \q
[postgres@localhost pgdata]$ pg_stop
waiting for server to shut down................. done
server stopped
[postgres@localhost pgdata]$ pg_start
server starting
[postgres@localhost pgdata]$ psql
psql (9.1.2)
Type "help" for help.

postgres=# select pg_current_xlog_location();
 pg_current_xlog_location 
--------------------------
 0/98000078
(1 row)