Use Case 1: Running pgBackRest Locally on the Database Host

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Description

  • pgBackRest runs locally on database servers and stores repository on remote storage (NFS, S3, Azure or GCS compatible object stores).
  • Cron task active on the node where to take backups.
  • Manually reconfigure cron task to take backup from another server.

Use case diagram

Configuration

Global Section

The [global] section will contain the:

  • repository location;
  • recommended settings;
  • retention policy.

This section's settings should be the same for all the nodes (primary and standbys).

Mount Points

Set repo1-type to posix or cifs and specify the repo1-path location to store backups and archives on a shared space:

repo1-type=posix
repo1-path=/backup_space
S3-compatible Object Stores
repo1-type=s3
repo1-path=/repo1
repo1-s3-bucket=bucket-name
repo1-s3-endpoint=...
repo1-s3-key=accessKey1
repo1-s3-key-secret=***
repo1-s3-region=...

The backups and archives will be stored in bucket-name/repo1.

It is possible to automatically retrieve temporary credentials when the AWS instance is associated with an IAM role. Credentials are automatically updated when they are <= 5 minutes from expiring.

To do this, instead of setting repo1-s3-key and repo1-s3-key-secret, use:

repo1-s3-key-type=auto
repo1-s3-role=authrole

To automatically retrieve web identity credentials, set the repo1-s3-key-type=web-id option and define the AWS_ROLE_ARN and AWS_WEB_IDENTITY_TOKEN_FILE environment variables.

Set the repo1-s3-kms-key-id option to enable server-side encryption using the specified AWS key management service key.

Azure-compatible Object Stores
repo1-type=azure
repo1-azure-key-type=shared
repo1-path=/repo1
repo1-azure-container=container-name
repo1-azure-account=pgbackrest
repo1-azure-key=***

To use the shared access signatures, set the repo1-azure-key-type option to sas and the repo1-azure-key option to the shared access signature token.

GCS-compatible Object Stores
repo1-type=gcs
repo1-gcs-key-type=service
repo1-path=/repo1
repo1-gcs-bucket=bucket-name
repo1-gcs-key=/etc/pgbackrest/gcs-key.json

repo1-gcs-key is a token or service key file depending on the repo1-gcs-key-type option.

Use those settings to enable encryption, parallel operations and ensure displaying enough information in the console and in the log file:

repo1-cipher-type=aes-256-cbc
repo1-cipher-pass=FIXME
process-max=FIXME
log-level-console=info
log-level-file=debug
start-fast=y
delta=y

Adjust the encryption passphrase and the maximum number of processes to use for compression usage and file transfer.

See the Recommended settings page for more details.

Retention Policy

To be able to delete old backups and archives, you have to define a retention policy. Use the following setting to only keep the latest full backup:

repo1-retention-full=1

See the Retention policy page for more options and details.

Stanza Section

The [demo] stanza section will be different on each database server and should contain:

  • the location of the PostgreSQL configuration files
pg1-path=/var/lib/pgsql/13/data

or for EDB Postgres Advanced Server

pg1-path=/var/lib/edb/as13/data
pg1-user=enterprisedb
pg1-port=5444
  • for every other PostgreSQL node
pg2-host=other_node_hostname_or_ip
pg2-path=/var/lib/pgsql/13/data

or for EDB Postgres Advanced Server

pg2-host=other_node_hostname_or_ip
pg2-host-user=enterprisedb
pg2-path=/var/lib/edb/as13/data
  • specific recovery option to set the replication primary_conninfo after the restore command is executed:
recovery-option=primary_conninfo=host=primary_vip user=replication_user ...

Setup Archiving

Once pgBackRest is configured, set up the database archiver process on each node:

# postgresql.conf
archive_mode = on
archive_command = 'pgbackrest --stanza=demo archive-push %p'

As changing the archive_mode parameter requires a service restart, and changing the archive_command only requires a configuration reload, we recommend enabling archive_mode with an empty archive_command (or pointing to /bin/true) when initiating a new database cluster.

See the Quick start page to set up a simple demo stanza configuration.

Assume the identity of the system user (postgres or enterprisedb) and initiate the pgBackRest repository from the primary server:

$ pgbackrest --stanza=demo stanza-create

Check the configuration and the archiving process:

$ pgbackrest --stanza=demo check

Backup and Restore

See the Quick start backups and restore sections for more details about those two commands.

Glossary

pgBackRest

delta log-level-console log-level-file pg-host-user pg-host pg-path pg-port pg-user process-max recovery-option repo-azure-account repo-azure-container repo-azure-key-type repo-azure-key repo-cipher-pass repo-cipher-type repo-path repo-retention-full repo-s3-bucket repo-s3-endpoint repo-s3-key-secret repo-s3-key-type repo-s3-key repo-s3-kms-key-id repo-s3-region repo-s3-role repo-type start-fast

PostgreSQL

archive_command archive_mode primary_conninfo

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