Only Progress DataDirect Connect database drivers (for ODBC, JDBC, and ADO.NET) include Application Failover to automatically and transparently redirect requests to an alternate database server if the primary server is unavailable because of a hardware failure or traffic overload. The DataDirect Application Failover feature:
- Ensures application reliability and data integrity
- Completely manages failover without additional coding or expensive server dependencies
- Provides a consistent, standards-based approach regardless of database server or application environment
Ensures Application Reliability and Data Integrity
The DataDirect Connect Application Failover feature guarantees data consistency and validity by ensuring that the alternate server is an exact mirror of the primary server with respect to transaction state. If for some reason the states don’t match, the driver will detect this and allow the application to take the appropriate action. DataDirect Connect also provides client-side load balancing which works with the Application Failover feature to help distribute new connections so that no one server is overwhelmed with connection requests.
Completely Manages Failover
DataDirect Connect completely manages Application Failover without additional application coding or server dependencies:
- Manages the re-connection to an alternate server list (which may include multiple reconnect attempts)
- Checks that the state of the data in the alternate server is consistent with the application
- Re-prepares the Select statement, re-executes the Select statement, and re-positions the cursor to the record that was being processed
Provides a Consistent, Standards-based Approach
The DataDirect Connect Application Failover implementation provides consistency regardless of database or operating environment to help reduce application development costs. In addition, DataDirect simplifies and standardizes the return code values, which greatly reduces the application code necessary to implement failover, and makes it easy to provide failover in heterogeneous database environments.
Delivers Superior Flexibility
The Application Failover feature is completely configurable and provides multiple failover options. You configure the list of alternate servers, number of re-try attempts and the associated wait period, and the failover options, including:
- Connection Failover - Ensures that new connections can be established, even if the primary server is not available.
- Extended Connection Failover - Supports new connections as well as lost connections by connecting to an alternate server while also restoring the state of a lost connection.
- Select Failover - Fails over to an alternate server while preserving the state of the connection, along with the work being performed by the Select statement. This includes re-positioning the cursor to the next row in a row that was returned by a select statement.
Reduce Application Development Costs
Because the DataDirect driver manages failover, you won't have to implement time-consuming proprietary code in the application or costly server configurations provided by the database vendors.