--- title: "[筆記] 在Ubuntu 18.04 下 透過 pgbarman streaming backup 備份 postgresql 10/ backup postgresql 10 with pgbarman straming backup in ubuntu 18.04" date: 2019-08-23T13:53:40+08:00 noSummary: false featuredImage: "https://h.cowbay.org/images/post-default-4.jpg" categories: ['筆記'] tags: ['postgresql','pgbarman'] author: "Eric Chang" keywords: - pgbarman - postgresql --- 很久以前就有看到這個用來備份postgresql 的 pgbarman https://www.pgbarman.org/ 前幾天老闆在slack 上面又提到，所以這次就花了點時間來玩玩看 不過呢，雖然有弄起來，但是還真不知道有些問題是怎麼解決的... pgbarman 的備份有分兩種 streaming && rsync/SSH 原理就不說了，我一直沒搞懂 postgresql 的 streaming .. 依照官方網站上的說法，比較推薦 streaming 備份的方式 原因是，設定相對簡單，WTF ! ``` On a general basis, starting from Barman 2.0, backup over streaming replication is the recommended setup for PostgreSQL 9.4 or higher The reason why we recommend streaming backup is that, based on our experience, it is easier to setup than the traditional one ``` 事實上呢，設定的確是很簡單，可是有個致命的缺點 ``` Because Barman transparently makes use of pg_basebackup, features such as incremental backup, parallel backup, deduplication, and network compression are currently not available. In this case, bandwidth limitation has some restrictions - compared to the traditional method via rsync. ``` 如果要做差異/增量備份， streaming backup 不能做 所以每次備份都是完整備份，也因此，barman server 需要準備很大的硬碟空間 以我測試的資料庫來說，一次備份，目前是133G ，如果一天四次，保留七天 就需要 133 x 4 x 7 = 3724G 咦，這樣看起來，其實也還好啦 XDD ______ 現在開始設定的部份 #### 設定 postgresql server IP: 192.168.11.19 hostname: hqs019 ##### 在postgresql 建立相關帳號 streaming backup 需要先在postgresql Server 上建立一個具有 superuser 權限的帳號 以及一個用來做replication 的資料庫帳號 這裡就簡單帶過 ``` sudo su - postgres psql create user barman with login superuser login password 'barmanpassword'; CREATE ROLE stream_barman WITH REPLICATION PASSWORD 'password' LOGIN; ``` ##### 鄉改 pg_hba.conf 然後修改 pg_hba.conf，加入底下兩行 ``` # for barman test host database_name barman 192.168.11.192/32 md5 host replication stream_barman 192.168.11.192/32 md5 ``` 當然，如果不考慮安全性問題， md5 直接改成用 trust ，可以省去一些麻煩。 ##### 修改 postgresql.conf 接著修改postgresql.conf ``` ### for barman test max_wal_senders = 5 max_replication_slots = 3 wal_level = 'archive' archive_mode = on ``` 重起 postgresql service #### 設定barman server IP: 192.168.11.192 hostname: barman ##### 安裝 barman barman 在18.04 中，已經被放到標準repository 中 所以只要直接 ``` sudo apt install barman ``` 就可以了 ##### 設定 barman.conf 安裝完成後，在/etc/barman.d/ 底下會有兩個範例檔案 ``` streaming-server.conf-template ssh-server.conf-template ``` 複製 streaming-server 檔案 ``` sudo cp /etc/barman.d/streaming-server.conf-template /etc/barman.d/hqs019.conf ``` 內容如下 ``` [hqs019] description = "hqs019 " conninfo = host=192.168.11.19 user=barman dbname=database_name password=barmanpassword streaming_conninfo = host=192.168.11.19 user=stream_barman dbname=database_name password=password backup_method = postgres retention_policy_mode = auto streaming_archiver = on slot_name = barman ``` 接著修改 /etc/barman.conf ``` [barman] barman_user = barman configuration_files_directory = /etc/barman.d barman_home = /var/lib/barman log_file = /var/log/barman/barman.log log_level = DEBUG compression = gzip immediate_checkpoint = true basebackup_retry_times = 3 basebackup_retry_sleep = 30 last_backup_maximum_age = 1 DAYS ``` 基本上這樣就設定完成了 ##### 檢查設定 barman 有一些指令可以用來檢查目前的設定 barman show-server hqs019 可以看到所有的設定，這裡的 hqs019 跟 barman.d/hqs019.conf 裡面用"[ ]" 包起來的名稱要一致 ``` barman@barman:~$ barman show-server hqs019 Server hqs019: active: True archiver: False archiver_batch_size: 0 backup_directory: /var/lib/barman/hqs019 backup_method: postgres backup_options: BackupOptions(['concurrent_backup']) bandwidth_limit: None barman_home: /var/lib/barman barman_lock_directory: /var/lib/barman basebackup_retry_sleep: 30 basebackup_retry_times: 3 basebackups_directory: /var/lib/barman/hqs019/base check_timeout: 30 compression: gzip config_file: /etc/postgresql/10/main/postgresql.conf connection_error: None conninfo: host=192.168.11.19 user=barman dbname=database_name password=barmanpassword current_size: 142740768562 current_xlog: 0000000100000264000000BA custom_compression_filter: None custom_decompression_filter: None data_directory: /database description: hqs019 disabled: False errors_directory: /var/lib/barman/hqs019/errors hba_file: /etc/postgresql/10/main/pg_hba.conf ident_file: /etc/postgresql/10/main/pg_ident.conf immediate_checkpoint: True incoming_wals_directory: /var/lib/barman/hqs019/incoming is_in_recovery: False is_superuser: True last_backup_maximum_age: 1 day (WARNING! latest backup is No available backups old) max_incoming_wals_queue: None minimum_redundancy: 0 msg_list: [] name: hqs019 network_compression: False parallel_jobs: 1 path_prefix: None pg_basebackup_bwlimit: True pg_basebackup_compatible: True pg_basebackup_installed: True pg_basebackup_path: /usr/bin/pg_basebackup pg_basebackup_tbls_mapping: True pg_basebackup_version: 10.10-0ubuntu0.18.04.1) pg_receivexlog_compatible: True pg_receivexlog_installed: True pg_receivexlog_path: /usr/bin/pg_receivewal pg_receivexlog_supports_slots: True pg_receivexlog_synchronous: False pg_receivexlog_version: 10.10-0ubuntu0.18.04.1) pgespresso_installed: False post_archive_retry_script: None post_archive_script: None post_backup_retry_script: None post_backup_script: None pre_archive_retry_script: None pre_archive_script: None pre_backup_retry_script: None pre_backup_script: None recovery_options: RecoveryOptions([]) replication_slot: Record(slot_name='barman', active=True, restart_lsn='264/BA000000') replication_slot_support: True retention_policy: None retention_policy_mode: auto reuse_backup: None server_txt_version: 10.10 slot_name: barman ssh_command: None streaming: True streaming_archiver: True streaming_archiver_batch_size: 0 streaming_archiver_name: barman_receive_wal streaming_backup_name: barman_streaming_backup streaming_conninfo: host=192.168.11.19 user=stream_barman dbname=database_name password=password streaming_supported: True streaming_wals_directory: /var/lib/barman/hqs019/streaming synchronous_standby_names: [''] systemid: 6688476041000599317 tablespace_bandwidth_limit: None timeline: 1 wal_level: replica wal_retention_policy: main wals_directory: /var/lib/barman/hqs019/wals xlogpos: 264/BA000F08 ``` 然後用 barman check hqs019 來檢查config 有沒有問題 ``` barman@barman:~$ barman check hqs019 Server hqs019: PostgreSQL: OK is_superuser: OK PostgreSQL streaming: OK wal_level: OK replication slot: OK directories: OK retention policy settings: OK backup maximum age: FAILED (interval provided: 1 day, latest backup age: No available backups) 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 pg_receivexlog: OK pg_receivexlog compatible: OK receive-wal running: OK archiver errors: OK barman@barman:~$ ``` 那個backup maximum age FAILED 不用管他，因為都還沒跑過備份，這邊錯誤是正常的 其他都OK 的話，就可以開始備份了 barman backup hqs019 ``` barman@ubuntu:~$ barman backup hqs019 Starting backup using postgres method for server hqs019 in /var/lib/barman/hqs019/base/20190823T082258 Backup start at LSN: 264/A10001A8 (0000000100000264000000A1, 000001A8) Starting backup copy via pg_basebackup for 20190823T082258 WARNING: pg_basebackup does not copy the PostgreSQL configuration files that reside outside PGDATA. Please manually backup the following files: /etc/postgresql/10/main/postgresql.conf /etc/postgresql/10/main/pg_hba.conf /etc/postgresql/10/main/pg_ident.conf Copy done (time: 1 hour, 6 minutes, 28 seconds) Finalising the backup. Backup size: 133.0 GiB Backup end at LSN: 264/A3000060 (0000000100000264000000A3, 00000060) Backup completed (start time: 2019-08-23 08:22:58.116372, elapsed time: 1 hour, 6 minutes, 28 seconds) Processing xlog segments from streaming for hqs019 0000000100000264000000A2 barman@ubuntu:~$ ``` 跑完可以用 barman list-backup hqs019 檢查 ``` barman@ubuntu:~$ barman list-backup hqs019 hqs019 20190823T082258 - Thu Aug 22 17:29:26 2019 - Size: 133.0 GiB - WAL Size: 0 B (tablespaces: tablespace_a:/var/lib/postgresql/10/main/tablespace_A, tablespace_b:/var/lib/postgresql/10/main/tablespace_B) ``` 要刪除的話，要加入 backupID ``` barman@ubuntu:~$ barman delete hqs019 20190822T171355 Deleting backup 20190822T171355 for server hqs019 Delete associated WAL segments: 00000001000002640000009F 0000000100000264000000A0 0000000100000264000000A1 Deleted backup 20190822T171355 (start time: Fri Aug 23 09:36:43 2019, elapsed time: 3 seconds) ``` restore 的部份，暫時沒有測試，我想應該是要找時間測試看看怎麼還原才對 不過呢，前面有提到，用streaming backup ，每一次備份都是完整備份，非常的佔用空間、時間、頻寬 所以還是要來試試看用rsync/SSH 備份的機制