Implementing pgBackRest for Backup and Restore in pgEdge

pgEdge enhances PostgreSQL by enabling distributed, multi-active database clusters designed for low-latency, globally scaled applications. However, distributed systems introduce new challenges in data protection and disaster recovery. In this blog, we'll outline the steps and best practices you should follow when implementing and maintaining a reliable backup and restore strategy for pgEdge environments using pgBackRest.  

pgBackRest is a robust, high-performance backup tool designed for PostgreSQL that offers features such as:

• Full, differential, and incremental backups

• Compression and encryption

• Parallelism and delta restores

• Point-in-Time Recovery (PITR)

• Seamless integration with WAL archiving

When combined with pgEdge, pgBackRest ensures data resilience across distributed nodes by supporting geographically redundant backups and rapid restoration of services after network interruption or failure.

In this blog, we'll:

• Define a consistent and reliable backup process for pgEdge clusters.

• Share steps to recover from data loss, node failures, or full-cluster outages.

• Guide both automated and manual backup/restore procedures.

• help you support compliance with organizational RTO (Recovery Time Objective) and RPO (Recovery Point Objective) policies.

We'll define the process for backing up and restoring PostgreSQL databases in a pgEdge cluster with pgBackRest. You can use this information to ensure consistency, reliability, and disaster recovery readiness in a distributed pgEdge PostgreSQL cluster. This information will be useful for you if you manage a:

• production or staging pgEdge cluster.

• a team responsible for backups and recovery.

• a cluster running pgEdge PostgreSQL 15+ with pgBackRest installed.

Prerequisites

Before working your way through this blog, you should ensure that you have:

• An installed and operational pgEdge cluster

• With pgBackRest installed on each node (or a centralized backup host)

• PostgreSQL WAL archiving is enabled (this is prompted during cluster setup)

• a configured backup repository (either posix or S3-compatible storage)

• Passwordless SSH access for centralized backup

You should also ensure that your cluster is running version 25.X of the pgEdge CLI:

Configuring pgBackRest on an Existing Cluster

There are multiple ways to deploy pgBackRest with a pgEdge cluster; if you are spinning up a new pgEdge cluster, you can deploy pgBackRest at the same time by using the cluster module to define a .json file that includes the pgBackRest specifications, and then initialize your cluster.

In the example that follows, we'll add pgBackRest to an existing pgEdge cluster.  To accomplish this, you'll use the pgEdge CLI to install and configure the pgEdge backrest bundle. This Multi-master-enabled pgBackRest bundle is designed specifically for pgEdge use cases.

The following are the steps involved in setting up the backrest:

• Install the latest version of the pgEdge backrest source code bundle.

• Create a pgBackRest stanza with the set-postgresqlconf API.

• Modify the PostgreSQL pg_hba.conf file and reload the configuration.

• Modify the stanza to configure the backup.

• Identify your backup repository; the current options are posix and S3.

• Update pgEdge Postgres to provide details like user identities, port information, and data directory location.

Configuring pgBackRest on an Existing pgEdge Cluster

First, we'll use pgEdge to install pgBackRest on each node of the cluster:

./pgedge install backrest

Then, we'll use the set-postgresqlconf API to update the postgresql.conf file in preparation for configuring pgBackRest:

./pgedge backrest set-postgresqlconf --stanza demo_stanza_n1 --pg1-path
/home/rocky/practice/pgedge/data/pg17 --repo1-path
/var/lib/pgbackrest/n1 --repo1-type posix --repo1-cipher-type aes-256-cbc

Next, we'll use the set-hbaconf API to update the pg_hba.conf file, configuring authentication for pgBackRest:

./pgedge backrest set-hbaconf

Then, we'll reload the server configuration so the changes take effect:

./pgedge psql 'select pg_reload_conf()' lcdb

Next, we'll configure our backup and create the backup stanza:

./pgedge set BACKUP stanza demo_stanza_n1
sudo mkdir -p /var/lib/pgbackrest_restore/n1
./pgedge set BACKUP restore_path /var/lib/pgbackrest_restore/n1
./pgedge set BACKUP repo1-host-user rocky
./pgedge set BACKUP pg1-path /home/rocky/practice/pgedge/data/pg17
./pgedge set BACKUP pg1-user rocky
./pgedge set BACKUP pg1-port 6432
./pgedge set BACKUP repo1-type posi

./pgedge backrest create-stanza --stanza=demo_stanza_n1
--repo1-path=/var/lib/pgbackrest/n1

Then, we start pgBackRest:

./pgedge backrest backup --repo1-path=/var/lib/pgbackrest/n1 --stanza=demo_stanza_n1

--pg1-path=/home/rocky/practice/pgedge/data/pg17

After starting pgBackRest, we can review a list of backups:

./pgedge backrest list-backups