Chapter 5. Migrating from internal Satellite databases to external databases
When you install Red Hat Satellite, the satellite-installer command installs PostgreSQL databases on the same server as Satellite. If you are using the default internal databases but want to start using external databases to help with the server load, you can migrate your internal databases to external databases.
To confirm whether your Satellite Server has internal or external databases, you can query the status of your databases:
For PostgreSQL, enter the following command:
satellite-maintain service status --only postgresql
# satellite-maintain service status --only postgresql
Red Hat does not provide support or tools for external database maintenance. This includes backups, upgrades, and database tuning. You must have your own database administrator to support and maintain external databases.
To migrate from the default internal databases to external databases, you must complete the following procedures:
- Section 5.2, “Preparing a host for external databases”. Prepare a Red Hat Enterprise Linux 8 server to host the external databases.
- Section 5.3, “Installing PostgreSQL”. Prepare PostgreSQL with databases for Satellite, Pulp and Candlepin with dedicated users owning them.
-
Section 5.4, “Migrating to external databases”. Edit the parameters of
satellite-installerto point to the new databases, and runsatellite-installer.
5.1. PostgreSQL as an external database considerations Copy linkLink copied to clipboard!
Foreman, Katello, and Candlepin use the PostgreSQL database. If you want to use PostgreSQL as an external database, the following information can help you decide if this option is right for your Satellite configuration. Satellite supports PostgreSQL version 12.
Advantages of external PostgreSQL
- Increase in free memory and free CPU on Satellite
-
Flexibility to set
shared_bufferson the PostgreSQL database to a high number without the risk of interfering with other services on Satellite - Flexibility to tune the PostgreSQL server’s system without adversely affecting Satellite operations
Disadvantages of external PostgreSQL
- Increase in deployment complexity that can make troubleshooting more difficult
- The external PostgreSQL server is an additional system to patch and maintain
- If either Satellite or the PostgreSQL database server suffers a hardware or storage failure, Satellite is not operational
- If there is latency between the Satellite server and database server, performance can suffer
If you suspect that the PostgreSQL database on your Satellite is causing performance problems, use the information in Satellite 6: How to enable postgres query logging to detect slow running queries to determine if you have slow queries. Queries that take longer than one second are typically caused by performance issues with large installations, and moving to an external database might not help. If you have slow queries, contact Red Hat Support.
5.2. Preparing a host for external databases Copy linkLink copied to clipboard!
Install a freshly provisioned system with the latest Red Hat Enterprise Linux 8 to host the external databases.
Subscriptions for Red Hat Enterprise Linux do not provide the correct service level agreement for using Satellite with external databases. You must also attach a Satellite subscription to the base operating system that you want to use for the external databases.
Prerequisites
- The prepared host must meet Satellite’s Storage Requirements.
Procedure
- Use the instructions in Attaching the Satellite Infrastructure Subscription to attach a Satellite subscription to your server.
Disable all repositories and enable only the following repositories:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Enable the following module:
dnf module enable satellite:el8
# dnf module enable satellite:el8Copy to Clipboard Copied! Toggle word wrap Toggle overflow NoteEnablement of the module
satellite:el8warns about a conflict withpostgresql:10andruby:2.5as these modules are set to the default module versions on Red Hat Enterprise Linux 8. The modulesatellite:el8has a dependency for the modulespostgresql:12andruby:2.7that will be enabled with thesatellite:el8module. These warnings do not cause installation process failure, hence can be ignored safely. For more information about modules and lifecycle streams on Red Hat Enterprise Linux 8, see Red Hat Enterprise Linux Application Streams Lifecycle.
5.3. Installing PostgreSQL Copy linkLink copied to clipboard!
You can install only the same version of PostgreSQL that is installed with the satellite-installer tool during an internal database installation. Satellite supports PostgreSQL version 12.
Procedure
To install PostgreSQL, enter the following command:
dnf install postgresql-server postgresql-evr postgresql-contrib
# dnf install postgresql-server postgresql-evr postgresql-contribCopy to Clipboard Copied! Toggle word wrap Toggle overflow To initialize PostgreSQL, enter the following command:
postgresql-setup initdb
# postgresql-setup initdbCopy to Clipboard Copied! Toggle word wrap Toggle overflow Edit the
/var/lib/pgsql/data/postgresql.conffile:vi /var/lib/pgsql/data/postgresql.conf
# vi /var/lib/pgsql/data/postgresql.confCopy to Clipboard Copied! Toggle word wrap Toggle overflow Note that the default configuration of external PostgreSQL needs to be adjusted to work with Satellite. The base recommended external database configuration adjustments are as follows:
- checkpoint_completion_target: 0.9
- max_connections: 500
- shared_buffers: 512MB
- work_mem: 4MB
Remove the
#and edit to listen to inbound connections:listen_addresses = '*'
listen_addresses = '*'Copy to Clipboard Copied! Toggle word wrap Toggle overflow Edit the
/var/lib/pgsql/data/pg_hba.conffile:vi /var/lib/pgsql/data/pg_hba.conf
# vi /var/lib/pgsql/data/pg_hba.confCopy to Clipboard Copied! Toggle word wrap Toggle overflow Add the following line to the file:
host all all Satellite_ip/32 md5
host all all Satellite_ip/32 md5Copy to Clipboard Copied! Toggle word wrap Toggle overflow To start, and enable PostgreSQL service, enter the following commands:
systemctl enable --now postgresql
# systemctl enable --now postgresqlCopy to Clipboard Copied! Toggle word wrap Toggle overflow Open the postgresql port on the external PostgreSQL server:
firewall-cmd --add-service=postgresql
# firewall-cmd --add-service=postgresqlCopy to Clipboard Copied! Toggle word wrap Toggle overflow Make the changes persistent:
firewall-cmd --runtime-to-permanent
# firewall-cmd --runtime-to-permanentCopy to Clipboard Copied! Toggle word wrap Toggle overflow Switch to the
postgresuser and start the PostgreSQL client:su - postgres -c psql
$ su - postgres -c psqlCopy to Clipboard Copied! Toggle word wrap Toggle overflow Create three databases and dedicated roles: one for Satellite, one for Candlepin, and one for Pulp:
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Connect to the Pulp database:
postgres=# \c pulpcore You are now connected to database "pulpcore" as user "postgres".
postgres=# \c pulpcore You are now connected to database "pulpcore" as user "postgres".Copy to Clipboard Copied! Toggle word wrap Toggle overflow Create the
hstoreextension:pulpcore=# CREATE EXTENSION IF NOT EXISTS "hstore"; CREATE EXTENSION
pulpcore=# CREATE EXTENSION IF NOT EXISTS "hstore"; CREATE EXTENSIONCopy to Clipboard Copied! Toggle word wrap Toggle overflow Exit the
postgresuser:\q
# \qCopy to Clipboard Copied! Toggle word wrap Toggle overflow From Satellite Server, test that you can access the database. If the connection succeeds, the commands return
1.PGPASSWORD='Foreman_Password' psql -h postgres.example.com -p 5432 -U foreman -d foreman -c "SELECT 1 as ping" PGPASSWORD='Candlepin_Password' psql -h postgres.example.com -p 5432 -U candlepin -d candlepin -c "SELECT 1 as ping" PGPASSWORD='Pulpcore_Password' psql -h postgres.example.com -p 5432 -U pulp -d pulpcore -c "SELECT 1 as ping"
# PGPASSWORD='Foreman_Password' psql -h postgres.example.com -p 5432 -U foreman -d foreman -c "SELECT 1 as ping" # PGPASSWORD='Candlepin_Password' psql -h postgres.example.com -p 5432 -U candlepin -d candlepin -c "SELECT 1 as ping" # PGPASSWORD='Pulpcore_Password' psql -h postgres.example.com -p 5432 -U pulp -d pulpcore -c "SELECT 1 as ping"Copy to Clipboard Copied! Toggle word wrap Toggle overflow
5.4. Migrating to external databases Copy linkLink copied to clipboard!
Back up and transfer existing data, then use the satellite-installer command to configure Satellite to connect to an external PostgreSQL database server.
Prerequisites
- You have installed and configured a PostgreSQL server on a Red Hat Enterprise Linux server.
Procedure
On Satellite Server, stop Satellite services:
satellite-maintain service stop
# satellite-maintain service stopCopy to Clipboard Copied! Toggle word wrap Toggle overflow Start the PostgreSQL services:
systemctl start postgresql
# systemctl start postgresqlCopy to Clipboard Copied! Toggle word wrap Toggle overflow Back up the internal databases:
satellite-maintain backup online \ --preserve-directory \ --skip-pulp-content \ /var/migration_backup
# satellite-maintain backup online \ --preserve-directory \ --skip-pulp-content \ /var/migration_backupCopy to Clipboard Copied! Toggle word wrap Toggle overflow Transfer the data to the new external databases:
PGPASSWORD='Foreman_Password' pg_restore -h postgres.example.com -U foreman -d foreman < /var/migration_backup/foreman.dump PGPASSWORD='Candlepin_Password' pg_restore -h postgres.example.com -U candlepin -d candlepin < /var/migration_backup/candlepin.dump PGPASSWORD='Pulpcore_Password' pg_restore -h postgres.example.com -U pulp -d pulpcore < /var/migration_backup/pulpcore.dump
PGPASSWORD='Foreman_Password' pg_restore -h postgres.example.com -U foreman -d foreman < /var/migration_backup/foreman.dump PGPASSWORD='Candlepin_Password' pg_restore -h postgres.example.com -U candlepin -d candlepin < /var/migration_backup/candlepin.dump PGPASSWORD='Pulpcore_Password' pg_restore -h postgres.example.com -U pulp -d pulpcore < /var/migration_backup/pulpcore.dumpCopy to Clipboard Copied! Toggle word wrap Toggle overflow Use the
satellite-installercommand to update Satellite to point to the new databases:Copy to Clipboard Copied! Toggle word wrap Toggle overflow