TIBCO EMS STEP -9 : PERSISTENT and NON_PERSISTENT and RELIABLE_DELIVERY

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Ø  When a producer sends a PERSISTENT message, the producer must wait for the server to reply with a confirmation. The message is persisted on disk by the server. This delivery mode ensures delivery of messages to the destination on the server in almost all circumstances. However, the cost is that this delivery mode incurs two-way network traffic for each message or committed transaction of a group of messages.
Ø  NON_PERSISTENT message omits the overhead of persisting the message on disk to improve performance. If authorization is enabled on the server, the default condition is for the producer to wait for the server to reply with a confirmation in the same manner as when using PERSISTENT mode.
Ø  RELIABLE_DELIVERY: EMS extends the JMS delivery modes to include reliable delivery. Sending a RELIABLE_DELIVERY message omits the server confirmation to improve performance.



Ø  When using RELIABLE_DELIVERY mode, the server never sends the producer a receipt confirmation or access denial and the producer does not wait for it.
Ø  Reliable mode decreases the volume of message traffic, allowing higher message rates, which is useful for messages containing time-dependent data, such as stock price quotations.
Ø  NON_PERSISTENT and RELIABLE_DELIVERY messages are never written to persistent storage. PERSISTENT messages are written to persistent storage when they are received by the EMS server.
Ø  Persistent messages sent to a queue are always written to disk. If server fails before sending persistent messages to subscribers , the server can be restarted and the persistent messages will be sent to the subscribers when they reconnect to the server.       










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