Mercredi 12 février 2025 à 23:05

Suite de ma note 2025-02-12_1511.

J'ai passé 5h40 sur un POC de barman, mais je n'ai pas eu beaucoup plus de succès qu'avec pgBackRest. Décidément, ces outils ne m'aiment pas 😔.

Repository du POC : https://github.com/stephane-klein/poc-barman

La commande barman check streaming-server retourne le message WAL archive: FAILED (please make sure WAL shipping is setup). Pour fixer cette erreur, je dois faire les manipulations suivantes que je trouve bizarre :

$ ./scripts/enter-in-pg1.sh
postgres=# select pg_switch_wal();
 pg_switch_wal
---------------
 0/206A330
(1 row)

et ensuite :

$ docker compose exec barman bash
root@5482aa5f8420:/# su barman
barman@5482aa5f8420:/$ barman cron
Starting WAL archiving for server streaming-server
barman@5482aa5f8420:/$ barman check streaming-server
Server streaming-server:
        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)
        backup minimum size: OK (0 B)
        wal maximum age: OK (no last_wal_maximum_age provided)
        wal size: OK (0 B)
        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

Je ne sais pas pourquoi je dois lancer select pg_switch_wal();.

J'ai pourtant configuré checkpoint_timeout='60s' :

    command: >
      postgres
      -c wal_level=replica
      -c summarize_wal=on
      -c checkpoint_timeout='60s'
      -c max_wal_size='100MB'

Je pensais que ce paramètre effectuait la même action que pg_switch_wal(); mais je constate que non.

Aussi, je constate que je dois aussi lancer pg_switch_wal(); pour que la commande suivante se termine :

barman@5482aa5f8420:/$ barman backup streaming-server --wait
Starting backup using postgres method for server streaming-server in /var/lib/barman/streaming-server/base/20250212T221703
Backup start at LSN: 0/5000B40 (000000010000000000000005, 00000B40)
Starting backup copy via pg_basebackup for 20250212T221703
Copy done (time: 1 second)
Finalising the backup.
Backup size: 22.3 MiB
Backup end at LSN: 0/7000000 (000000010000000000000007, 00000000)
Backup completed (start time: 2025-02-12 22:17:03.190492, elapsed time: 1 second)
Waiting for the WAL file 000000010000000000000007 from server 'streaming-server'
Processing xlog segments from streaming for streaming-server
        000000010000000000000005
Processing xlog segments from streaming for streaming-server
        000000010000000000000006

Je ne comprends pas non plus pourquoi.