Chapter 5. Migration

1. Install the rh-mariadb101 Software Collection.

   yum install rh-mariadb101-mariadb-server

2. Inspect the configuration of rh-mariadb101, which is stored in the /etc/opt/rh/rh-mariadb101/my.cnf file and the /etc/opt/rh/rh-mariadb101/my.cnf.d/ directory. Compare it with the configuration of rh-mariadb100 stored in /etc/opt/rh/rh-mariadb100/my.cnf and /etc/opt/rh/rh-mariadb100/my.cnf.d/ and adjust it if necessary.
3. Stop the rh-mariadb100 database server, if it is still running.

   service rh-mariadb100-mariadb stop

4. All the data of the rh-mariadb100 Software Collection is stored in the /var/opt/rh/rh-mariadb100/lib/mysql/ directory. Copy the whole content of this directory to /var/opt/rh/rh-mariadb101/lib/mysql/. You can also move the content but remember to back up your data before you continue to upgrade.
5. Start the rh-mariadb101 database server.

   service rh-mariadb101-mariadb start

6. Perform the data migration.

   scl enable rh-mariadb101 mysql_upgrade

   If the root user has a non-empty password defined (it should have a password defined), it is necessary to call the mysql_upgrade utility with the -p option and specify the password.

   scl enable rh-mariadb101 -- mysql_upgrade -p

1. Install the MongoDB servers and shells from the rh-mongodb30upg and rh-mongodb32 Software Collections:

   ~]# yum install rh-mongodb30upg rh-mongodb30upg-mongodb rh-mongodb32 rh-mongodb32-mongodb

2. Connect the mongo shell from the rh-mongodb26 Collection to your MongoDB 2.6 server (for example, running on localhost, port 27017).

   ~]$ scl enable rh-mongodb26 'mongo --host localhost --port 27017 admin'

3. In the mongo shell, check your data set for compatibility issues mentioned above and fix the ones that affect your application.
4. Stop the MongoDB 2.6 server:

   ~]# systemctl stop rh-mongodb26-mongod.service

   Use the service rh-mongodb26-mongodb stop command if you are using Red Hat Enterprise Linux 6.
5. Copy your data to the new location:

   ~]# cp -a /var/opt/rh/rh-mongodb26/lib/mongodb/* /var/opt/rh/rh-mongodb32/lib/mongodb

6. Change the dbpath variable in the /etc/opt/rh/rh-mongodb30upg/mongod.conf file to /var/opt/rh/rh-mongodb32/lib/mongodb/.
7. Start the MongoDB server from the rh-mongodb30upg Software Collection:

   ~]# systemctl start rh-mongodb30upg-mongod.service

   Use the service rh-mongodb30upg-mongodb start command if you are using Red Hat Enterprise Linux 6.
8. Connect the mongo shell from the rh-mongodb32 Collection to your MongoDB 3.0 server (for example, running on localhost, port 27017).

   ~]$ scl enable rh-mongodb30upg 'mongo --host localhost --port 27017 admin'

9. In the mongo shell, check your data set for compatibility issues mentioned above and fix the ones that affect your application.
10. Stop the MongoDB 3.0 server.

    ~]# systemctl stop rh-mongodb30upg-mongod.service

    Use the service rh-mongodb30upg-mongodb stop command if you are using Red Hat Enterprise Linux 6.
11. Configure the rh-mongodb32-mongod daemon in the /etc/opt/rh/rh-mongodb32/mongod.conf file.
12. MongoDB 3.2 has the new default storage engine, WiredTiger, which introduces performance improvements. To be able to run the MongoDB server with old data, configure the rh-mongodb32-mongod daemon to use the old storage engine. Uncomment the engine property in the storage section in the /etc/opt/rh/rh-mongodb32/mongod.conf file and change its value to mmapv1.
13. Start the MongoDB 3.2 server.

    ~]# systemctl start rh-mongodb32-mongod.service

    Use the service rh-mongodb32-mongodb start command if you are using Red Hat Enterprise Linux 6.
14. If you want to use the WiredTiger storage engine, you have to perform additional migration steps described in the MongoDB documentation.

    ~]# yum install rh-mongodb32-mongo-tools
    ~]$ scl enable rh-mongodb32 'mongodump --out ~/mongodb.dump'
    ~]# systemctl stop rh-mongodb32-mongod.service
    ~]# rm -rf /var/opt/rh/rh-mongodb32/lib/mongodb/*

    Change the engine property in the /etc/opt/rh/rh-mongodb32/mongod.conf to wiredTiger. Use the service rh-mongodb32-mongodb stop command if you are using Red Hat Enterprise Linux 6.

    ~]# systemctl start rh-mongodb32-mongod.service
    ~]$ scl enable rh-mongodb32 'mongorestore ~/mongodb.dump'

    Use the service rh-mongodb32-mongodb start command if you are using Red Hat Enterprise Linux 6.

1. Install the rh-mysql57 Software Collection.

   yum install rh-mysql57-mysql-server

2. Inspect the configuration of rh-mysql57, which is stored in the /etc/opt/rh/rh-mysql57/my.cnf file and the /etc/opt/rh/rh-mysql57/my.cnf.d/ directory. Compare it with the configuration of rh-mysql56 stored in /etc/opt/rh/rh-mysql56/my.cnf and /etc/opt/rh/rh-mysql56/my.cnf.d/ and adjust it if necessary.
3. Stop the rh-mysql56 database server, if it is still running.

   service rh-mysql56-mysqld stop

4. All data of the rh-mysql56 Software Collection is stored in the /var/opt/rh/rh-mysql56/lib/mysql/ directory. Copy the whole content of this directory to /var/opt/rh/rh-mysql57/lib/mysql/. You can also move the content but remember to back up your data before you continue to upgrade.
5. Start the rh-mysql57 database server.

   service rh-mysql57-mysqld start

6. Perform the data migration.

   scl enable rh-mysql57 mysql_upgrade

   If the root user has a non-empty password defined (it should have a password defined), it is necessary to call the mysql_upgrade utility with the -p option and specify the password.

   scl enable rh-mysql57 -- mysql_upgrade -p

Procedure 5.1. Fast Upgrade Using the pg_upgrade Tool

1. Stop the old PostgreSQL server to ensure that the data is not in an inconsistent state. To do so, type the following at a shell prompt as root:

   service postgresql stop

   To verify that the server is not running, type:

   service postgresql status

2. Verify that the old directory /var/lib/pgsql/data/ exists:

   file /var/lib/pgsql/data/

   and back up your data.
3. Verify that the new data directory /var/opt/rh/rh-postgresql95/lib/pgsql/data/ does not exist:

   file /var/opt/rh/rh-postgresql95/lib/pgsql/data/

   If you are running a fresh installation of PostgreSQL 9.5, this directory should not be present in your system. If it is, back it up by running the following command as root:

   mv /var/opt/rh/rh-postgresql95/lib/pgsql/data{,-scl-backup}

4. Upgrade the database data for the new server by running the following command as root:

   scl enable rh-postgresql95 -- postgresql-setup --upgrade

   Alternatively, you can use the /opt/rh/rh-postgresql95/root/usr/bin/postgresql-setup --upgrade command.
   Note that you can use the --upgrade-from option for upgrade from different versions of PostgreSQL. The list of possible upgrade scenarios is available using the --upgrade-ids option.
   It is recommended that you read the resulting /var/lib/pgsql/upgrade_rh-postgresql95-postgresql.log log file to find out if any problems occurred during the upgrade.
5. Start the new server as root:

   service rh-postgresql95-postgresql start

   It is also advised that you run the analyze_new_cluster.sh script as follows:

   su - postgres -c 'scl enable rh-postgresql95 ~/analyze_new_cluster.sh'

6. Optionally, you can configure the PostgreSQL 9.5 server to start automatically at boot time. To disable the old system PostgreSQL server, type the following command as root:

   chkconfig postgresql off

   To enable the PostgreSQL 9.5 server, type as root:

   chkconfig rh-postgresql95-postgresql on

7. If your configuration differs from the default one, make sure to update configuration files, especially the /var/opt/rh/rh-postgresql95/lib/pgsql/data/pg_hba.conf configuration file. Otherwise only the postgres user will be allowed to access the database.

Procedure 5.2. Performing a Dump and Restore Upgrade

1. Ensure that the old PostgreSQL server is running by typing the following at a shell prompt as root:

   service postgresql start

2. Dump all data in the PostgreSQL database into a script file. As root, type:

   su - postgres -c 'pg_dumpall > ~/pgdump_file.sql'

3. Stop the old server by running the following command as root:

   service postgresql stop

4. Initialize the data directory for the new server as root:

   scl enable rh-postgresql95-postgresql -- postgresql-setup --initdb

5. Start the new server as root:

   service rh-postgresql95-postgresql start

6. Import data from the previously created SQL file:

   su - postgres -c 'scl enable rh-postgresql95 "psql -f ~/pgdump_file.sql postgres"'

7. Optionally, you can configure the PostgreSQL 9.5 server to start automatically at boot time. To disable the old system PostgreSQL server, type the following command as root:

   chkconfig postgresql off

   To enable the PostgreSQL 9.5 server, type as root:

   chkconfig rh-postgresql95-postgresql on

8. If your configuration differs from the default one, make sure to update configuration files, especially the /var/opt/rh/rh-postgresql95/lib/pgsql/data/pg_hba.conf configuration file. Otherwise only the postgres user will be allowed to access the database.

Procedure 5.3. Fast Upgrade Using the pg_upgrade Tool

1. Stop the old PostgreSQL server to ensure that the data is not in an inconsistent state. To do so, type the following at a shell prompt as root:

   service rh-postgresql94-postgresql stop

   To verify that the server is not running, type:

   service rh-postgresql94-postgresql status

2. Verify that the old directory /var/opt/rh/rh-postgresql94/lib/pgsql/data/ exists:

   file /var/opt/rh/rh-postgresql94/lib/pgsql/data/

   and back up your data.
3. Verify that the new data directory /var/opt/rh/rh-postgresql95/lib/pgsql/data/ does not exist:

   file /var/opt/rh/rh-postgresql95/lib/pgsql/data/

   If you are running a fresh installation of PostgreSQL 9.5, this directory should not be present in your system. If it is, back it up by running the following command as root:

   mv /var/opt/rh/rh-postgresql95/lib/pgsql/data{,-scl-backup}

4. Upgrade the database data for the new server by running the following command as root:

   scl enable rh-postgresql95 -- postgresql-setup --upgrade --upgrade-from=rh-postgresql94-postgresql

   Alternatively, you can use the /opt/rh/rh-postgresql95/root/usr/bin/postgresql-setup --upgrade --upgrade-from=rh-postgresql94-postgresql command.
   Note that you can use the --upgrade-from option for upgrading from different versions of PostgreSQL. The list of possible upgrade scenarios is available using the --upgrade-ids option.
   It is recommended that you read the resulting /var/lib/pgsql/upgrade_rh-postgresql95-postgresql.log log file to find out if any problems occurred during the upgrade.
5. Start the new server as root:

   service rh-postgresql95-postgresql start

   It is also advised that you run the analyze_new_cluster.sh script as follows:

   su - postgres -c 'scl enable rh-postgresql95 ~/analyze_new_cluster.sh'

6. Optionally, you can configure the PostgreSQL 9.5 server to start automatically at boot time. To disable the old PostgreSQL 9.4 server, type the following command as root:

   chkconfig rh-postgresql94-postgreqsql off

   To enable the PostgreSQL 9.5 server, type as root:

   chkconfig rh-postgresql95-postgresql on

7. If your configuration differs from the default one, make sure to update configuration files, especially the /var/opt/rh/rh-postgresql95/lib/pgsql/data/pg_hba.conf configuration file. Otherwise only the postgres user will be allowed to access the database.

Procedure 5.4. Performing a Dump and Restore Upgrade

1. Ensure that the old PostgreSQL server is running by typing the following at a shell prompt as root:

   service rh-postgresql94-postgresql start

2. Dump all data in the PostgreSQL database into a script file. As root, type:

   su - postgres -c 'scl enable rh-postgresql94 "pg_dumpall > ~/pgdump_file.sql"'

3. Stop the old server by running the following command as root:

   service rh-postgresql94-postgresql stop

4. Initialize the data directory for the new server as root:

   scl enable rh-postgresql95-postgresql -- postgresql-setup --initdb

5. Start the new server as root:

   service rh-postgresql95-postgresql start

6. Import data from the previously created SQL file:

   su - postgres -c 'scl enable rh-postgresql95 "psql -f ~/pgdump_file.sql postgres"'

7. Optionally, you can configure the PostgreSQL 9.5 server to start automatically at boot time. To disable the old PostgreSQL 9.4 server, type the following command as root:

   chkconfig rh-postgresql94-postgresql off

   To enable the PostgreSQL 9.5 server, type as root:

   chkconfig rh-postgresql95-postgresql on

8. If your configuration differs from the default one, make sure to update configuration files, especially the /var/opt/rh/rh-postgresql95/lib/pgsql/data/pg_hba.conf configuration file. Otherwise only the postgres user will be allowed to access the database.