Feature pages are design documents that developers have created while collaborating on oVirt.

Most of them are outdated , but provide historical design context.

They are not user documentation and should not be treated as such.

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Remote DB

Summary

Remote DB feature means working with a Postgres instance on a remote host.

Owner

Current status

The code is developed and is a part of the upstream code.

Design and flow

Setup

  • During the engine-setup operation, user is asked to select 'remote' or 'local' installation. Default value 'local' is offered.

     If entered 'local', the installation will continue and perform installation on the local machine. * If entered 'remote', the additional set of questions will be presented.    Additional questions include: DB Admin username, DB Port, Remote Db password and "Security usage" parameters.

  • Installation proceeds with normal flow.
  • During the normal flow, additional parameters (if entered by user) are used during DB creation and JBoss configuration.

DB configuration parameters are stored in ~/.pgpass file, including remote host, port and username/password. JBoss configuration is stored in /usr/share/jboss-as/standalone/configuration/standalone.xml file.

  • If setup is rerun, the same parameters are used in "upgradeDb" function. Also, see next section for the upgrade logic.

Upgrade

  • During the upgrade, the DB connection values are received from ~/.pgpass file and used for connection.
  • The upgrade works as follows:

    * First, the packages are upgraded if necessary. * Before performing the DB upgrade, a backup is taken. * After the backup, the default DB (engine) is renamed to engine-  * If renaming fails, yum rollback is performed, and user is notified about possible active connections.  * If renaming succeeds, DB upgrade is started. * If upgrade fails, the renamed DB is removed and yum rollback is performed. * If upgrade succeeds, the engine-`` is renamed back to 'engine'.

Cleanup

  • During the upgrade, the DB connection values are received from ~/.pgpass file and used for connection.
  • If DB drop fails user is notified about possible active connections.

Unattended (silent) installation

It is possible to use an answer file for the silent installation. The values for the RemoteDb are:

  DB_REMOTE_INSTALL=local
  DB_HOST=10.1.1.1
  DB_PORT=5433
  DB_ADMIN=remotedb_test
  DB_REMOTE_PASS=54321
  DB_SECURE_CONNECTION=no
  DB_LOCAL_PASS=admin!ad

To use with local installation, only DB_REMOTE_INSTALL=local and DB_LOCAL_PASS values are required.

To use with remote installation, use DB_REMOTE_INSTALL=remote and configure DB_HOST, DB_PORT, DB_ADMIN, DB_REMOTE_PASS and DB_SECURE_CONNECTION values as needed.

It is recommended to generate the answer file automatically:

engine-setup --gen-answer-file=

…and then update its parameters accordingly with the installation requirements. After that, proceed with installation using the answer file:

engine-setup --answer-file=