Red Hat Training

A Red Hat training course is available for Red Hat JBoss Operations Network

Chapter 2. Setting up Databases

2.1. Configuring PostgreSQL

Running Red Hat JBoss Operations Network with PostgreSQL requires three things:
  • Adequate PostgreSQL settings for memory, timeouts, connections, and related settings
  • A database
  • A user with adequate permissions
JBoss ON supports PostgreSQL 8.4.x, 9.0.x, 9.1.x, 9.2.x, 9.3.x*, 9.4.x*, 9.5.x*
* Support added by JBoss ON 3.3 Update 06.

2.1.1. Installing PostgreSQL

You can download the Microsoft Windows binaries you need from: https://www.postgresql.org/download/windows/
Use YUM to install PostgreSQL:
sudo yum install postgresql postgresql-server
To install a specific version of PostgreSQL, go to: https://yum.postgresql.org/rpmchart.php and download the postgresql, postgresql-server and postgresql-libs RPM packages and install via yum from the download directory. For example:
sudo yum install
postgresql91-9.1.24-2PGDG.rhel6.x86_64.rpm
postgresql91-libs-9.1.24-2PGDG.rhel6.x86_64.rpm
postgresql91-server-9.1.24-2PGDG.rhel6.x86_64.rpm

2.1.2. Configuring PostgreSQL

Important
The following configuration is provided as an example of configuring this server quickly for a JBoss ON testing environment. Suggested values in these procedures are not be used in production environments. The procedure is not be used as a supported way of configuring a production server. Always follow the database provider configuration instructions carefully when configuring a production environment.
For detailed information about setting up client authentication for PostgreSQL users and databases, see the PostgreSQL documentation for the supported version at http://www.postgresql.org/docs/8.4/interactive/client-authentication.html.
Note
Ensure that the Postgres authentication mechanism is properly configured for the configuration commands to work.
  1. Optional. Change the password for the Unix user for PostgreSQL:
    sudo passwd postgres
  2. Initialize the PostgreSQL database. The database must be initialized before starting the server.
    • For installs using Red Hat Enterprise Linux 6 (and earlier) repositories:
      sudo service postgresql initdb
    • For installs using downloaded binaries on Red Hat Enterprise Linux 6 (and earlier):
      sudo service postgresql-<version> initdb
      Where: <version> = <major>.<minor>
      For example:
      sudo service postgresql-9.2 initdb
    • For installs using Red Hat Enterprise Linux 7 (and later) repositories:
      sudo /usr/bin/postgresql-setup initdb
    • For installs using downloaded binaries on Red Hat Enterprise Linux 7 (and later):
      sudo /usr/pgsql-<version>bin/postgresql<version_short>-setup initdb
      Where: <version_short> = <major><minor>
      For example:
      sudo /usr/pgsql-9.2/bin/postgresql92-setup initdb
  3. Start the PostgreSQL service.
    • On Red Hat Enterprise Linux 6 (and earlier) using repository install:
      sudo service postgresql start
      sudo chkconfig postgresql on
    • On Red Hat Enterprise Linux 6 (and earlier) using downloaded binaries:
      sudo service postgresql-<version> start
      sudo chkconfig postgresql-<version> on
    • On Red Hat Enterprise Linux 7 (and later) using repository install:
      sudo systemctl enable postgresql.service
      sudo systemctl start postgresql.service
    • On Red Hat Enterprise Linux 7 (and later) using downloaded binaries:
      sudo systemctl enable postgresql-<version>.service
      sudo systemctl start postgresql-<version>.service
    • On Microsoft Windows:
      net start pgsql-<version>
  4. Set up a password for the postgres user on the database:
    # su - postgres
    $ psql
    postgres=# ALTER USER postgres PASSWORD 'password';
    ALTER ROLE
  5. Create a PostgreSQL role named rhqadmin, where 'password' should be replaced with a strong password.
    postgres=# CREATE USER rhqadmin PASSWORD 'password';
    CREATE ROLE
    Important
    Although the default postgresql credentials expected by rhqctl are user rhqadmin and password rhqadmin, these credentials should not be used as they present a security risk. The relevant change to rhqctl is covered in Section 3.6, “About the rhqctl Script”.
  6. Create a PostgreSQL database named rhq, specifying the rhqadmin role as the owner.
    postgres=# CREATE DATABASE rhq OWNER rhqadmin;
    CREATE DATABASE
  7. Use the following command to locate the pg_hba.conf file:
    postgres=# SHOW hba_file;
  8. Use \q to quit psql.
  9. Give users on the computer access to the database. To allow all users, add the appropriate connection settings for each connection type (local, IPv4, and IPv6) to the data/pg_hba.conf configuration file, for both local and external connections:
    # TYPE DATABASE     USER       ADDRESS            METHOD
    
    # "local" is for Unix domain socket connections only
    local   all         all                               md5
    # IPv4 local connections:
    host    all         all         127.0.0.1/32          md5
    host    all         all         172.31.7.0/24         md5
    # IPv6 local connections:
    host    all         all         ::1/128               md5
    Using all all sets these settings for every user to every PostgreSQL database. This settings can be applied to only the JBoss ON database by using rhq all or even to specific users for JBoss ON, such as rhq rhqadmin. Changing the METHOD values to md5 ensures passwords are encrypted, not sent as plain text.
  10. Restart the database service.
    • On Red Hat Enterprise Linux 6 (and earlier):
      sudo service postgresql restart
    • On Red Hat Enterprise Linux 7 (and later):
      sudo systemctl restart postgresql
    • On Red Hat Enterprise Linux 7 (and later) using downloaded binaries:
      sudo systemctl restart postgresql-<version>
  11. Make the configuration changes in Section 2.1.3, “Setting PostgreSQL Parameters”.

2.1.3. Setting PostgreSQL Parameters

There are several settings in the PostgreSQL server configuration that can be tuned to provide better performance for JBoss ON.

2.1.3.1. Editing the postgresql.conf File

PostgreSQL requires minor changes to the database configuration in the postgresql.conf file.
  1. Make sure that an adequate amount of memory and system resources are assigned to accommodate the JBoss ON database.
    ## not necessary  if the database is started with the -i flag
    listen_addresses = '*'
    
    ## performance changes for JBoss ON
    shared_buffers = 80MB   #  default is 32MB
    work_mem = 2048   #  default is 1MB
    checkpoint_segments = 10 #  default is 3
    Note
    The parameter statement_timeout should not be set. If postgressql.conf contains a statement_timeout parameter, it should be overridden for the JBoss ON database user:
    ALTER USER rhqadmin SET statement_timeout=0;

2.1.3.2. Setting Kernel Parameters

Consider adjusting the kernel parameters for your system. The PostgreSQL documentation on Managing Kernel Resources has more information.

2.1.3.3. Editing pg_hba.conf

Update the pg_hba.conf file to allow the newly-created role to connect from the machine the JBoss ON server is installed on, such as localhost. Adding client connections is covered in the PostgreSQL documentation in the Client Authentication section.
After editing the pg_hba.conf file, restart PostgreSQL for the changes to take effect. If no errors are displayed, the database is now ready to support a JBoss ON installation.
For more information on tuning Postgres, see the PostgreSQL documentation about Tuning your PostgreSQL Server.

2.1.3.4. Fixes for "Relation RHQ_Principal does not exist" Error

Sometimes the database connection is marked as valid but the install still fails with the Relation RHQ_Principal does not exist error. This occurs when a new database is created by running initdb in a non-C locale through PostgreSQL instances.
To fix this error:
  1. Using a database explorer, create an empty table called RHQ_PRINCIPAL in the database used for JBoss ON.
  2. Click Install server.
    The installer displays a warning about an existing schema. Overwrite the existing schema as it only consists of one empty table.
Another option is to specify the encoding of the created database as SQL-ASCII at creation time. For example:
initdb -D /my/test/data -E SQL_ASCII --locale en_US.UTF-8