1 / 10

Message Service System

Message Service System. The Message System Paradigm. The Message System or Message-Oriented Middleware (MOM) paradigm is an elaboration of the basic message-passing paradigm . A message system serves as an intermediary among separate , independent processes .

cecily
Télécharger la présentation

Message Service System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Message Service System

  2. The Message System Paradigm • The Message System or Message-Oriented Middleware (MOM) paradigm is an elaboration ofthebasic message-passing paradigm. • A message systemserves as an intermediary among separate, independent processes. • A message system acts as a switchfor messages, through which processes exchange messages asynchronously, in a decoupled manner. • A sender deposits a message with the message system, which forwards it to a message queue associated with each receiver.

  3. The Message System Paradigm

  4. Message System Models Two subtypes of message system models: • Point-to-Point • Publish-Subscribe

  5. The Point-To-Point Message Model • A message systemforwards a message from the sender to the receiver’smessage queue. Unlike the basic message passing model, the middleware provides a message depository, and allows the sending and the receiving to be decoupled. • Via the middleware, a senderdeposits a message in the message queueof the receiving process. • A receiving processextractsthe messagesfrom itsmessage queue, and handles each one accordingly. • Compared to the basic message-passing model, this paradigm provides the additional abstraction for asynchronous operations.

  6. The Publish/Subscribe Message Model • Each message is associated with a specific topic or event. Applications interested in the occurrence of a specific event may subscribeto messages for that event. • When the awaited event occurs, the process publishes a message announcing the event or topic. The middleware message system distributes the message to all its subscribers. • The publish operation allows a process to multicast to a group of processes, and the subscribe operation allows a process to listen for such multicast. • This model offers a powerful abstraction for multicasting or group communication

  7. Toolkits based on the Message-System Paradigm • The MOM paradigm has had a long history in distributed applications. • Message Queue Services (MQS) have been in use since the 1980’s. • The IBM MQ*Series6 is an example of such a facility. http://www-4.ibm.com/software/ts/mqseries/ • Other existing support for this paradigm are • Microsoft’s Message Queue (MSQ) • Java’s Message Service

  8. Short Message Service (SMS) • The transmission of short text messagesto and from a mobile phone, fax machine and/or IP address. • Messages must be no longer than 160 alpha-numeric characters and contain no images or graphics. • Once a message is sent, it is received by a Short Message Service Center (SMSC),which must then get it to the appropriate mobile device. • The SMSC sends a SMS Request to the home location register (HLR) to find the roaming receiver. • Once the HLR receives the request, it will respond to the SMSC with the receiver’s status: 1) inactive or active 2) where receiver is roaming. • Ref: http://www.webopedia.com/TERM/S/short_message_service.html

  9. Short Message Service (SMS) • If the response is "inactive", then the SMSC will hold onto the message for a period of time. • When the receiver accesses his/her device, the HLR sends a SMS Notification to the SMSC, and the SMSC will attempt delivery. • The SMSC transfers the message in a Short Message DeliveryPoint to Point format to the serving system. The systempages the device, and if it responds, the message gets delivered. • The SMSC receives verification that the message was received by the receiver, then categorizes the message as "sent" and will not attempt to send again. • Ref: http://www.webopedia.com/TERM/S/short_message_service.html

  10. Sources of Information • Sun's JMS Tutorial http://java.sun.com/products/jms/tutorial/html/jmsTOC.fm.html • Microsoft's Message Queue(MSMQ) http://msdn.microsoft.com/library/psdk/msmq/msmq • IBM's MQ-Series http://www-4.ibm.com/software/ts/mqseries/

More Related