Connection retry is a functionality that automatically retries to obtain a connection when there are no available connections in the connection pool and when the establishment of a physical connection fails. By using the connection retry functionality, if an attempt to obtain a connection fails, you need not use the user program to retry to obtain a connection.

You can retry to obtain a connection when one of the following conditions is satisfied:

• All the following conditions are satisfied and there are no available connections (unused connections) in the connection pool:
  
  • The line 'waiting for a connection when connections deplete' is disabled.
  • The total number of connections in the connection pool has reached the maximum number of connections to be pooled.
• When a physical connection cannot be established due to any of the following conditions:
  
  • The total number of connections in the connection pool has reached the maximum number of connections to be pooled, and there are no unused connections with matching authentication information.
  • The total number of connections in the connection pool has not reached the maximum number of connections to be pooled.
  • Connection pooling is disabled.

Note that if a connection cannot be obtained even after retrying, an exception is reported to the application program and the process of obtaining a connection fails.

For the operations to be performed when the connection pool depletes, follow the description in 3.15.2 Waiting for a connection when connections deplete.

To implement the connection retry functionality, you must set up the following content as the resource adapter properties:

• Retry count
  Specifies the number of times the process will be retried.
  
• Retry interval
  Specifies the interval until the next retry attempt in seconds.
  

Note that if the retry count and retry interval is increased, the requests might have to wait when the processing to obtain connections accumulate.

For details on the resource adapter settings, see 3.15.13 Settings in the execution environment.

Organization of this subsection

(1) Preconditions