Shulou(Shulou.com)06/01 Report--

Pg10 sets up master / slave switching for stream replication.

Configuration

Main library 10.10.10.13 pghost4

Reserve 10.10.10.14 pghost5

When there is a problem with the test master library, the standby library will be automatically switched to the new master library after it is stopped. The old master library should now be a standby library, start it to verify the status. It was found that the repository could not be started. The repository is started in the following ways.

The new slave database is started through pg_ctl start, and the alarm log appears.

[root@pghost4 ~] # su-pg10

Pg10@pghost4- > pg_ctl start

Waiting for server to start....2019-12-20 21 LOG 4410 CST [23416] LOG: listening on IPv4 address "0.0.0.0", port 1921

2019-12-20 21 listening on IPv6 address 4415 CST [23416] LOG: listening on IPv6 address ":", port 1921

2019-12-20 21 listening on Unix socket 4415 CST [23416] LOG: listening on Unix socket "/ tmp/.s.PGSQL.1921"

2019-12-20 21 database system was shut down in recovery at 4414 CST [23417] LOG: database system was shut down in recovery at 2019-12-20 21:33:31 CST

2019-12-20 21 4414 CST [23417] LOG: entering standby mode

2019-12-20 21 requested timeline 44 is not a child of this server's history 10.014 CST [23417] FATAL: requested timeline 2

2019-12-20 21 on timeline 44 on timeline 10.014 CST [23417] DETAIL: Latest checkpoint is at 000028 on timeline 1, but in the history of the requested timeline, the server forked off from that timeline at 0/C000098.

2019-12-20 21 PID 4415 CST [23416] LOG: startup process (PID 23417) exited with exit code 1

2019-12-20 21 4415 CST [23416] LOG: aborting startup due to startup process failure

2019-12-20 21 4415 CST [23416] LOG: database system is shut down

Stopped waiting

Pg_ctl: could not start server

Examine the log output.

As you can see from the above, the 00000002.history in the pg_wal directory of the new library is not consistent with the new main library.

Pg10@pghost4- > ll

Total 273M

-rw- 1 pg10 pg10 16m Dec 18 22:40 0000000100000000000001

-rw- 1 pg10 pg10 16m Dec 18 23:01 00000001000000000002

-rw- 1 pg10 pg10 16m Dec 18 23:02 00000001000000000003

-rw- 1 pg10 pg10 16m Dec 18 23:06 00000001000000000004

-rw- 1 pg10 pg10 16m Dec 18 23:39 00000001000000000005

-rw- 1 pg10 pg10 16m Dec 18 23:51 00000001000000000006

-rw- 1 pg10 pg10 16m Dec 18 23:55 00000001000000000007

-rw- 1 pg10 pg10 16m Dec 18 23:58 00000001000000000008

-rw- 1 pg10 pg10 16m Dec 19 00:15 0000000100000000000009

-rw- 1 pg10 pg10 16m Dec 19 00:15 0000000100000000000A

-rw- 1 pg10 pg10 16m Dec 19 00:27 0000000100000000000B

-rw- 1 pg10 pg10 16m Dec 19 00:29 0000000100000000000C

-rw- 1 pg10 pg10 16m Dec 19 00:34 0000000100000000000D

-rw- 1 pg10 pg10 16m Dec 19 00:36 0000000100000000000E

-rw- 1 pg10 pg10 16m Dec 19 00:36 0000000100000000000F

-rw- 1 pg10 pg10 302 Dec 19 00:36 00000001000000000000000F.00000028.backup

-rw- 1 pg10 pg10 16m Dec 19 00:38 0000000100000000000010

-rw- 1 pg10 pg10 16m Dec 20 21:33 0000000100000000000011

-rw- 1 pg10 pg10 41 Dec 19 00:30 00000002.history

Drwx- 2 pg10 pg10 4.0K Dec 20 21:31 archive_status

Pg10@pghost4- > more 00000002.history

1 0/C000098 no recovery target specified

Pg10@pghost4- >

Then look at the directory under the path of the new main library

Pg10@pghost4- > ll

Total 132K

-rw- 1 pg10 pg10 206 Dec 19 00:36 backup_label.old

Drwx- 5 pg10 pg10 4.0K Dec 19 00:36 base

Drwx- 2 pg10 pg10 4.0K Dec 20 21:27 global

Drwx- 2 pg10 pg10 4.0K Dec 19 00:36 pg_commit_ts

Drwx- 2 pg10 pg10 4.0K Dec 19 00:36 pg_dynshmem

-rw- 1 pg10 pg10 4.6K Dec 19 00:36 pg_hba.conf

-rw- 1 pg10 pg10 1.6K Dec 19 00:36 pg_ident.conf

Drwx- 4 pg10 pg10 4.0K Dec 19 00:38 pg_logical

Drwx- 4 pg10 pg10 4.0K Dec 19 00:36 pg_multixact

Drwx- 2 pg10 pg10 4.0K Dec 19 00:37 pg_notify

Drwx- 2 pg10 pg10 4.0K Dec 19 00:36 pg_replslot

Drwx- 2 pg10 pg10 4.0K Dec 19 00:36 pg_serial

Drwx- 2 pg10 pg10 4.0K Dec 19 00:36 pg_snapshots

Drwx- 2 pg10 pg10 4.0K Dec 19 00:36 pg_stat

Drwx- 2 pg10 pg10 4.0K Dec 20 21:48 pg_stat_tmp

Drwx- 2 pg10 pg10 4.0K Dec 19 00:38 pg_subtrans

Drwx- 2 pg10 pg10 4.0K Dec 19 00:36 pg_tblspc

Drwx- 2 pg10 pg10 4.0K Dec 19 00:36 pg_twophase

-rw- 1 pg10 pg10 3 Dec 19 00:36 PG_VERSION

Drwx- 3 pg10 pg10 4.0K Dec 19 00:38 pg_wal

Drwx- 2 pg10 pg10 4.0K Dec 19 00:36 pg_xact

-rw- 1 pg10 pg10 88 Dec 19 00:36 postgresql.auto.conf

-rw- 1 pg10 pg10 23K Dec 19 00:36 postgresql.conf

-rw- 1 pg10 pg10 31 Dec 19 00:37 postmaster.opts

-rw- 1 pg10 pg10 74 Dec 19 00:38 postmaster.pid

-rw-r--r-- 1 pg10 pg10 5.8K Dec 19 00:37 recovery.done

Pg10@pghost4- > cd pg_wal/pg10@pghost4- > llbr/ > pg10@pghost4- > ll

-rw- 1 pg10 pg10 16m Dec 19 00:36 0000000100000000000F

-rw- 1 pg10 pg10 16m Dec 19 00:38 0000000100000000000010

-rw- 1 pg10 pg10 16M Dec 19 00:38 000000010000000000000011.partial

-rw- 1 pg10 pg10 16m Dec 19 00:38 00000002000000000011

-rw- 1 pg10 pg10 42 Dec 19 00:38 00000002.history

Drwx- 2 pg10 pg10 4.0K Dec 19 00:38 archive_statuspg10@pghost4- > pwdbr/ > pg10@pghost4- > pwd

Pg10@pghost4- > more 00000002.history

10 / 11000098 no recovery target specified

Back up the 00000002.history of the new repository and delete it.

Transfer the new master library to the new standby library.

And then activate.

Pg10@pghost4- > scp 00000002.history 10.10.10.13:/data/pg10/data/pg_wal/

Pg10@10.10.10.13's password:

00000002.history 100% 42 0.0KB/s 00:00

Pg10@pghost4- >

Pg10@pghost4- > pg_ctl start

Waiting for server to start....2019-12-20 21 LOG 51V 25.142 CST [23486] LOG: listening on IPv4 address "0.0.0.0", port 1921

2019-12-20 21 listening on IPv6 address 51V 25.142 CST [23486] LOG: listening on IPv6 address ":", port 1921

2019-12-20 21 listening on Unix socket 51V 25.144 CST [23486] LOG: listening on Unix socket "/ tmp/.s.PGSQL.1921"

2019-12-20 21 database system was shut down in recovery at 51 1V 25.155 CST [23487] LOG: database system was shut down in recovery at 2019-12-20 21:33:31 CST

2019-12-20 21 entering standby mode 51 51 15 15 CST [23487] LOG: entering standby mode

2019-12-20 21 consistent recovery state reached at 51 1V 25.171 CST [23487] LOG: consistent recovery state reached at 0amp 11000098

2019-12-20 21 invalid record length at 51V 25.171 CST [23487] LOG: invalid record length at 0amp 11000098: wanted 24, got 0

2019-12-20 21 database system is ready to accept read only connections 51V 25.171 CST [23486] database system is ready to accept read only connections

2019-12-20 21 started streaming WAL from primary at 51 1V 25 179 CST [23491] LOG: started streaming WAL from primary at 0 Universe 11000000 on timeline 2

2019-12-20 21 redo starts at 51V 25.225 CST [23487] LOG: redo starts at 0 Unix 11000098

Done

Server started

Pg10@pghost4- >

Found that it has been activated.

Pg10@pghost4- > pg_controldata | grep cluster

Database cluster state: in archive recovery

Pg10@pghost4- >

You can see that the new repository is in standby mode.

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