Upgrading Percona Distribution for PostgreSQL from 11 to 12

This document describes the in-place upgrade of Percona Distribution for PostgreSQL using the pg_upgrade tool. The in-place upgrade means installing a new version without removing the old version and keeping the data files on the server.

See also

pg_upgrade Documentation:

https://www.postgresql.org/docs/12/pgupgrade.html

Similar to installing, we recommend you to upgrade Percona Distribution for PostgreSQL from Percona repositories.

Important

A major upgrade is a risky process because of many changes between versions and issues that might occur during or after the upgrade. Therefore, make sure to back up your data first. The backup tools are out of scope of this document. Use the backup tool of your choice.

The general in-place upgrade flow for Percona Distribution for PostgreSQL is the following:

1. Install Percona Distribution for PostgreSQL 12 packages.

2. Stop the PostgreSQL service.

3. Check the upgrade without modifying the data.

4. Upgrade Percona Distribution for PostgreSQL.

5. Start PostgreSQL service.

6. Execute the analyze_new_cluster.sh script to generate statistics so the system is usable.

7. Delete old packages and configuration files.

The exact steps may differ depending on the package manager of your operating system.

On Debian and Ubuntu using apt

Important

Run all commands as root or via sudo.

1. Install Percona Distribution for PostgreSQL 12 packages.

   • Enable Percona repository using the percona-release utility:

   $ sudo percona-release setup ppg-12
   

   • Install Percona Distribution for PostgreSQL 12 package:

   $ sudo apt install percona-postgresql-12
   

2. Stop the postgresql service.

   $ sudo systemctl stop postgresql.service
   

   This stops both Percona Distribution for PostgreSQL 11 and 12.

3. Run the database upgrade.

   • Log in as the postgres user.

   $ sudo su postgres
   

   • Change the current directory to the tmp directory where logs and some scripts will be recorded:

   $ cd tmp/
   

   • Check the ability to upgrade Percona Distribution for PostgreSQL from 11 to 12:

   $ /usr/lib/postgresql/12/bin/pg_upgrade \
   --old-datadir=/var/lib/postgresql/11/main \
   --new-datadir=/var/lib/postgresql/12/main  \
   --old-bindir=/usr/lib/postgresql/11/bin  \
   --new-bindir=/usr/lib/postgresql/12/bin  \
   --old-options '-c config_file=/etc/postgresql/11/main/postgresql.conf' \
   --new-options '-c config_file=/etc/postgresql/12/main/postgresql.conf' \
   --check
   

   The --check flag here instructs pg_upgrade to only check the upgrade without changing any data.

   • Upgrade the Percona Distribution for PostgreSQL

   $ /usr/lib/postgresql/12/bin/pg_upgrade \
   --old-datadir=/var/lib/postgresql/11/main \
   --new-datadir=/var/lib/postgresql/12/main  \
   --old-bindir=/usr/lib/postgresql/11/bin  \
   --new-bindir=/usr/lib/postgresql/12/bin  \
   --old-options '-c config_file=/etc/postgresql/11/main/postgresql.conf' \
   --new-options '-c config_file=/etc/postgresql/12/main/postgresql.conf' \
   --link
   

   The --link flag creates hard links to the files on the old version cluster so you don’t need to copy data. If you don’t wish to use the --link option, make sure that you have enough disk space to store 2 copies of files for both old version and new version clusters.

   • Go back to the regular user:

   $ exit
   

   • The Percona Distribution for PostgreSQL 11 uses the 5432 port while the Percona Distribution for PostgreSQL 12 is set up to use the 5433 port by default. To start the Percona Distribution for PostgreSQL 12, swap ports in the configuration files of both versions.

   $ sudo vim /etc/postgresql/12/main/postgresql.conf
   $ port = 5433 # Change to 5432 here
   $ sudo vim /etc/postgresql/11/main/postgresql.conf
   $ port = 5432 # Change to 5433 here
   

4. Start the postgreqsl service.

   $ sudo systemctl start postgresql.service
   

5. Check the postgresql version.

   $ #Log in as a postgres user
   $ sudo su postgres
   $ #Check the database version
   $ psql -c "SELECT version();"
   

6. After the upgrade, the Optimizer statistics are not transferred to the new cluster. Run the vaccumdb command to analyze the new cluster:

   $ /usr/lib/postgresql/12/bin/vacuumdb --all --analyze-in-stages
   

7. Delete the old cluster’s data files:

   $ ./delete_old_cluster.sh
   $ sudo rm -rf /etc/postgresql/12/main
   $ #Logout
   $ exit
   

On Red Hat Enterprise Linux and derivatives using yum

Important

Run all commands as root or via sudo.

1. Install Percona Distribution for PostgreSQL 12 packages

   • Enable Percona repository using the percona-release utility:

   $ sudo percona-release setup ppg-12
   

   • Install Percona Distribution for PostgreSQL 12:

   $ sudo yum install percona-postgresql12-server
   

2. Set up Percona Distribution for PostgreSQL 12 cluster

   • Log is as the postgres user

   $ sudo su postgres
   

   • Set up locale settings

   $ export LC_ALL="en_US.UTF-8"
   $ export LC_CTYPE="en_US.UTF-8"
   

   • Initialize cluster with the new data directory

   $ /usr/pgsql-12/bin/initdb -D /var/lib/pgsql/12/data
   

3. Stop the postgresql 11 service

   $ sudo systemctl stop postgresql-11
   

4. Run the database upgrade.

   • Log in as the postgres user

   $ sudo su postgres
   

«««< HEAD

* Check the ability to upgrade Percona Distribution for PostgreSQL from 11 to 12:

   ```{.bash data-prompt="$"}
   $ /usr/pgsql-12/bin/pg_upgrade \
   --old-bindir /usr/pgsql-11/bin \
   --new-bindir /usr/pgsql-12/bin  \
   --old-datadir /var/lib/pgsql/11/data \
   --new-datadir /var/lib/pgsql/12/data \
   --check
   ```

   The `--check` flag here instructs `pg_upgrade` to only check the upgrade without changing any data.


* Upgrade the Percona Distribution for PostgreSQL

   ```{.bash data-prompt="$"}
   $ /usr/pgsql-12/bin/pg_upgrade \
   --old-bindir /usr/pgsql-11/bin \
   --new-bindir /usr/pgsql-12/bin  \
   --old-datadir /var/lib/pgsql/11/data \
   --new-datadir /var/lib/pgsql/12/data \
   --link 
   ```

   The  `--link` flag creates hard links to the files on the old version cluster so you don’t need to copy data.
   If you don’t wish to use the `--link` option, make sure that you have enough disk space to store 2 copies of files for both old version and new version clusters.

1. Start the postgresql 12 service.

   $ systemctl start postgresql-13
   

2. Check postgresql status

   $ sudo systemctl status postgresql-12
   

3. After the upgrade, the Optimizer statistics are not transferred to the new cluster. Run the vaccumdb command to analyze the new cluster:

   • Log in as the postgres user

   $ sudo su postgres
   

   • Run the vaccumdb command

   $ /usr/pgsql-12/bin/vacuumdb --all --analyze-in-stages
   

4. Delete Percona Distribution for PostgreSQL 11 configuration files

   $ ./delete_old_cluster.sh
   

5. Delete Percona Distribution for PostgreSQL old data files

   $ sudo rm -rf /var/lib/pgsql/11/data
   

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