In-place Postgres major version upgrades v5

You can upgrade a PGD node to a newer major version of Postgres using the command-line utility bdr_pg_upgrade.

bdr_pg_upgrade is a wrapper around the standard pg_upgrade adding PGD-specific logic to the process to ensure a smooth upgrade.

Terminology

This terminology is used when describing the upgrade process and components involved:

Postgres cluster: — The database files, both executables and data, which make up a Postgres database instance on a system when run.

Old Postgres cluster — The existing Postgres cluster to upgrade, the one from which to migrate data.

New Postgres cluster — The new Postgres cluster that data is migrated to. This Postgres cluster must be one major version ahead of the old cluster.

Precautions

Standard Postgres major version upgrade precautions apply, including the fact both Postgres clusters must meet all the requirements for pg_upgrade.

Additionally, don't use bdr_pg_upgrade if other tools are using replication slots and replication origins. Only PGD slots and origins are restored after the upgrade.

You must meet several prerequisites for bdr_pg_upgrade:

• Disconnect applications using the old Postgres cluster. You can, for example, redirect them to another node in the PGD cluster.
• Configure peer authentication for both Postgres clusters. bdr_pg_upgrade requires peer authentication.
• The same PGD version must be installed on both clusters.
• The PGD version must be 4.1.0 or above. Version 3.7.22 and later is also supported.
• The new cluster must be in a shutdown state.
• You must install PGD packages in the new cluster.
• The new cluster must be already initialized and configured as needed to match the old cluster configuration.
• Databases, tables, and other objects must not exist in the new cluster.

We also recommend having the old Postgres cluster up prior to running bdr_pg_upgrade. The CLI starts the old Postgres cluster if it's shut down.

Usage

To upgrade to a newer major version of Postgres, you must first install the new version.

bdr_pg_upgrade command-line

bdr_pg_upgrade passes all parameters to pg_upgrade. Therefore, you can specify any parameters supported by pg_upgrade.

Synopsis

bdr_pg_upgrade [OPTION] ...

Options

In addition to the options for pg_upgrade, you can pass the following parameters to bdr_pg_upgrade:

Required parameters

Specify these parameters either in the command line or, for all but the --database parameter, in their equivalent environment variable. They're used by bdr_pg_upgrade.

• -b, --old-bindir — Old Postgres cluster bin directory.
• -B, --new-bindir— New Postgres cluster bin directory.
• -d, --old-datadir — Old Postgres cluster data directory.
• -D, --new-datadir — New Postgres cluster data directory.
• --database — PGD database name.

Optional parameters

These parameters are optional and are used by bdr_pg_upgrade.

• -p, --old-port — Old cluster port number.
• -s, --socketdir — Directory to use for postmaster sockets during upgrade.
• --check — Specify to only perform checks and not modify clusters.

Other parameters

Any other parameter that's not one of the above is passed to pg_upgrade. pg_upgrade accepts the following parameters:

• -j, --jobs — Number of simultaneous processes or threads to use.
• -k, --link — Use hard links instead of copying files to the new cluster.
• -o, --old-options — Option to pass to old postgres command. Multiple invocations are appended.
• -O, --new-options — Option to pass to new postgres command. Multiple invocations are appended.
• -N, --no-sync — Don't wait for all files in the upgraded cluster to be written to disk.
• -P, --new-port — New cluster port number.
• -r, --retain — Retain SQL and log files even after successful completion.
• -U, --username — Cluster's install user name.
• --clone — Use efficient file cloning.

Environment variables

You can use these environment variables in place of command line parameters:

• PGBINOLD — Old Postgres cluster bin directory.
• PGBINNEW — New Postgres cluster bin directory.
• PGDATAOLD — Old Postgres cluster data directory.
• PGDATANEW — New Postgres cluster data directory.
• PGPORTOLD — Old Postgres cluster port number.
• PGSOCKETDIR — Directory to use for postmaster sockets during upgrade.

Example

Given a scenario where:

• Old Postgres cluster bin directory is /usr/lib/postgresql/13/bin.
• New Postgres cluster bin directory is /usr/lib/postgresql/14/bin.
• Old Postgres cluster data directory is /var/lib/postgresql/13/main.
• New Postgres cluster data directory is /var/lib/postgresql/14/main.
• Database name is bdrdb.

You can use the following command to upgrade the cluster:

bdr_pg_upgrade \
--old-bindir /usr/lib/postgresql/13/bin \
--new-bindir /usr/lib/postgresql/14/bin \
--old-datadir /var/lib/postgresql/13/main \
--new-datadir /var/lib/postgresql/14/main \
--database bdrdb

Steps performed

These steps are performed when running bdr_pg_upgrade.

PGD Postgres checks

pg_upgrade steps

Standard pg_upgrade steps are performed.

PGD post-upgrade steps

• On this page
• Terminology
• Precautions
• Usage