Java: A concrete example of Queue’s utilization: Multi Servers Dispatching (Part8)

After my posts concerning presentation of Queue/BlockingQueue, and the Queue/BlockingQueue implementations I would continue with a post about a concrete example of these implementations: the Multi servers dispatching.

Multi-server operating system:
This system provides a pool of available connections due to:

• ConfigParametersAndUtils: Configuration’s parameters and useful methods
• MyHostConnectionProxy: Encapsulates the real connection. This class manage the connection transaction timeout too, if a connection duration exceed the defined transactionTimeOut, it will be automatically closed.
• MyHostConnectionProxyFactory: The main goals of MyHostConnectionProxyFactory class is to provide and close the connection via its connection pools:
  – Unused and available connections (connectionPool) ;
  – Used connections (usedconnectionPool) ;
  – Unavailable connections (unavailableConnectionPool);
  -> Open Connection: execute the MyHostConnectionProxyFactory.openConnection method;
  -> Open Connection with a same server: execute the MyHostConnectionProxyFactory.openConnectionWithSameServer method;
  -> Close a connection: execute the MyHostConnectionProxyFactory.closeConnection method;
• MyHostConnectionProxyAutoCloseConnection: It is a runnable is attached to each used connection in order to detect a timeout (MyHostConnectionProxy.transactionTimeOut) and close the connection (use of ScheduledExecutorService),
• MyHostConnectionMock: Mock connection encapsulated by the instance of MyHostConnectionProxy in the tests

Test n°1:
The test case Launch5ThreadsTest checks the working of multi server dispatching with a pool of 2 connections available and 5 runnable clients.

Initializing the connection pools:

Here, the traces concerning the connections established for each client thread and the mock remote server:

the traces concerning the connections closure:

Test n°2:
The test case Launch3ThreadsTimeOutWithAutoCloseTest checks the working of the AutoClose runnable used to detect a timeout and close the connection with a pool of 2 connections available and 3 runnable clients. This runnable is attached to each connection.

Initializing the connection pools:

To enforce the timeout, we have changed the connection time out to 1 seconds. So, if an connection is open more than this time. A thread will close it automatically. Here, the traces concerning the MyHostConnectionProxyAutoCloseConnection runnable for each connection:

Here, a concrete example of the Queues implementations, however, contact me for more explanations.

The source code of this article and the a test cases are in the ZIP file attachement.

Download: java_queue.zip

Best regards,