Persistent Database Connections

For information

• Database connections are managed in a connection pool by default.

  • Upon requirement, a connection from the connection pool will be assigned to a client. After the connection has been used (e.g. processing of an SQL query), it is retained and returned to the pool.

• If a persistent database connection is to be used instead (duration of the database connection = duration of the user session), connection pooling will be deactivated.

• Persistent database connections are connections which are not closed after an event has been processed.

• The connection will only be closed when the client is closed.

• Thus, there is always one connection per client. Further connections will be opened upon requirement.

Details

• Whether one single persistent database connection is used per client session is controlled via the database__persistent_db_session parameter.

• The setting affects the entire PLANTA project instance and therefore applies system-wide.

• By default, the setting is on false.

• To activate this setting, the the database__persistent_db_session environment variable in the manager container of the server must be set to true.

Advantages

• During a user session, user-specific data can, e.g., be stored in temporary tables.

Disadvantages

• Database connection limits must be adjusted to the maximum number of sessions.

  • Number of users

  • Connections for the extraction of auto-IDs (connection is established shortly and closed again)

  • One connection for the server session

• Connection will be kept open.

  • Resources will be used.