# Создание и восстановление резервной копии с помощью barman 21. Утилита barman содержит два типа конфиг. Свой и для каждого кластера PostgreSQL. Посмотрим на них ``` postgres$ cat /etc/barman.conf postgres$ ls /etc/barman.d/ total 20 drwxr-xr-x 2 root root 4096 Apr 5 05:55 ./ drwxr-xr-x. 82 root root 4096 Apr 5 05:55 ../ -rw-r--r-- 1 root root 947 Nov 4 08:55 passive-server.conf-template -rw-r--r-- 1 root root 1565 Nov 4 08:55 ssh-server.conf-template -rw-r--r-- 1 root root 1492 Nov 4 08:55 streaming-server.conf-template ``` 22. Создадим роль в PostgreSQL для выполнения бекапов и дадим ему соответствующие права ```sql postgres$ psql psql (12.6) Type "help" for help. 5432=> CREATE ROLE backup WITH PASSWORD 'backup' LOGIN REPLICATION SUPERUSER; CREATE ROLE ``` 23. Выйдем из-под пользователя postgres и зайдем под пользователем root ``` postgres$ exit student$ sudo -i ``` 24. Создадим файл backup и внесем туда данные ```conf root$ nano /etc/barman.d/pg_backup.conf [pg_backup] description = "PostgreSQL DB" conninfo = host=localhost port=5432 user=backup password=backup dbname=template1 streaming_archiver = true streaming_conninfo = host=localhost port=5432 user=backup password=backup backup_method = postgres slot_name = pg_backup ``` 25. Проверим работу barman ```log root$ barman check pg_backup Server pg_backup: WAL archive: FAILED (please make sure WAL shipping is setup) PostgreSQL: OK superuser or standard user with backup privileges: OK PostgreSQL streaming: OK wal_level: OK replication slot: FAILED (replication slot 'pg_backup' doesn't exist. Please execute 'barman receive-wal --create-slot pg_backup') directories: OK retention policy settings: OK backup maximum age: OK (no last_backup_maximum_age provided) compression settings: OK failed backups: OK (there are 0 failed backups) minimum redundancy requirements: OK (have 0 backups, expected at least 0) pg_basebackup: OK pg_basebackup compatible: OK pg_basebackup supports tablespaces mapping: OK systemid coherence: OK (no system Id stored on disk) pg_receivexlog: OK pg_receivexlog compatible: OK receive-wal running: FAILED (See the Barman log file for more details) archiver errors: OK ``` Видим, что у нас много ошибок и предупреждений. Давайте исправим их. 26. Создадим слот репликации pg_backup ``` root$ barman receive-wal --create-slot pg_backup Creating physical replication slot 'pg_backup' on server 'pg_backup' Replication slot 'pg_backup' created ``` 27. Проверим работу barman ```log root$ barman check pg_backup Server pg_backup: PostgreSQL: OK superuser or standard user with backup privileges: OK PostgreSQL streaming: OK wal_level: OK replication slot: OK directories: OK retention policy settings: OK backup maximum age: OK (no last_backup_maximum_age provided) compression settings: OK failed backups: OK (there are 0 failed backups) minimum redundancy requirements: OK (have 0 backups, expected at least 0) pg_basebackup: OK pg_basebackup compatible: OK pg_basebackup supports tablespaces mapping: OK systemid coherence: OK (no system Id stored on disk) pg_receivexlog: OK pg_receivexlog compatible: OK receive-wal running: OK archiver errors: OK ``` 28. Создадим резервную копию ```log root$ sudo -u barman barman backup pg_backup Starting backup using postgres method for server pg_backup in /var/lib/barman/pg_backup/base/20210405T094734 Backup start at LSN: 0/3000060 (000000010000000000000003, 00000060) Starting backup copy via pg_basebackup for 20210405T094734 Copy done (time: 3 seconds) Finalising the backup. This is the first backup for server pg_backup WAL segments preceding the current backup have been found: 000000010000000000000001 from server pg_backup has been removed 000000010000000000000002 from server pg_backup has been removed Backup size: 24.2 MiB Backup end at LSN: 0/5000000 (000000010000000000000004, 00000000) Backup completed (start time: 2021-04-05 09:47:34.216170, elapsed time: 3 seconds) Processing xlog segments from streaming for pg_backup 000000010000000000000003 WARNING: IMPORTANT: this backup is classified as WAITING_FOR_WALS, meaning that Barman has not received yet all the required WAL files for the backup consistency. This is a common behaviour in concurrent backup scenarios, and Barman automatically set the backup as DONE once all the required WAL files have been archived. Hint: execute the backup command with '--wait' ``` 29. О чем говорит это предупреждение? Давайте исправим такую ошибку ``` root$ barman switch-wal pg_backup The WAL file 000000010000000000000005 has been closed on server 'pg_backup' ``` 30. Посмотрим список резервных копий ``` root$ barman list-backup pg_backup pg_backup 20210405T094734 - Mon Apr 5 09:47:37 2021 - Size: 40.2 MiB - WAL Size: 1s6.0 MiB ``` 31. Давайте восстановим резервную копию. Делаем «кустарно». Прошу гнилыми помидорами не закидывать. Данные скрипт приводится в качестве примера в тестовом окружении. В рабочей среде нужно делать всё через ssh. ```log root$ sudo -u postgres pg_ctl -D /var/lib/pgsql/12/main5432 stop root$ chown -R barman:barman /var/lib/pgsql root$ barman recover pg_backup 20210405T094734 /var/lib/pgsql/12/main5432 Starting local restore for server pg_backup using backup 20210405T094734 Destination directory: /var/lib/pgsql/12/main5432 Copying the base backup. Copying required WAL segments. Generating archive status files Identify dangerous settings in destination directory. Recovery completed (start time: 2021-04-05 10:41:58.225068, elapsed time: 1 second) Your PostgreSQL server has been successfully prepared for recovery! root$ chown -R postgres:postgres /var/lib/pgsql ``` 32. Переходим к пользователю postgres и запускаем кластер PostgreSQL ```log root$ exit student$ sudo -u postgres -i postgres$ pg_ctl -D /var/lib/pgsql/12/main5432 start waiting for server to start....2021-04-05 10:48:09.751 UTC [2776] LOG: starting PostgreSQL 12.6 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44), 64-bit 2021-04-05 10:48:09.752 UTC [2776] LOG: listening on IPv4 address "127.0.0.1", port 5432 2021-04-05 10:48:09.755 UTC [2776] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432" 2021-04-05 10:48:09.762 UTC [2776] LOG: listening on Unix socket "/tmp/.s.PGSQL.5432" 2021-04-05 10:48:09.779 UTC [2776] LOG: redirecting log output to logging collector process 2021-04-05 10:48:09.779 UTC [2776] HINT: Future log output will appear in directory "log". done server started ``` 33. Проверяем работу кластера и данные в таблице test ```sql postgres$ psql -p5433 -d wal_g 5433=> select * from test; id | name ----+--------- 2 | Value 2 3 | Value 3 1 | Value 4 (3 rows) 5433=> \q ```