WAL-G

WAL-G is a simple and efficient archival restoration tool for PostgreSQL that simplifies Continuous Archiving and Point-in-Time Recovery (PITR) and can store backups in S3, Google Cloud Storage, Azure, Swift, remote host (via SSH), or local file system.

In order to set up continuous backups, you need to do the following:

Configure wal-g access to external storage

For example. If you use GCP GCS you should configure ENV Variables

WALG_GS_PREFIX=gs://my-bucket/walg-folder
GOOGLE_APPLICATION_CREDENTIALS=/path/to/service/account.json

Enable archiving of logs in Postgres and specify archive command and restore_command

postgresql.conf

archive_command = 'wal-g wal-push %p'
restore_command = 'wal-g wal-fetch %f %p'

Make a base backup

For taking a backup you should run wal-g backup-push inside the AidboxDb container

wal-g backup-push $PGDATA
wal-g backup-list

You can always restore the database from base backup if your database is corrupted.

To start rotating wal logs and backups schedule you can schedule retain cron job

wal-g delete retain FULL 30 --confirm

This will delete all but 30 latest backups.

Backups integrity

WAL-G includes wal-g wal-verify a command that checks backup integrity.

wal-g wal-verify integrity timeline # perform integrity and timeline checks
wal-g wal-verify integrity # perform only integrity check

Aidboxdb recovery:

1. Configure WAL-G access to external storage

2. Download backup wal-g backup-pull $PGDATA

3. Configure the wal-g wal-fetch restore command

4. Start Postgres

Postgres download all the missing logs and read them on start.

In replica mode Postgres operates in "read-only" mode, continues to receive WAL logs and lags minimum one WAL file behind main instance.

Incremental backups

You can configure incremental backups with env variable WALG_DELTA_MAX_STEPS.

So the backup will be faster, but the recovery process will take longer.

What WAL-G doesn't work for?

• WAL-G is not a replacement of pg_dump. pg_dump is used to create a logical dump of one or several DBs in cluster.

• WAL-G doesn't schedule backup automatically.