TIBCO EMS STEP -9.1 : PERSISTENT and NON_PERSISTENT and RELIABLE_DELIVERY

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Ø  Persistent messages published to a topic are written to disk only if that topic has at least one durable subscriber or one subscriber with a fault-tolerant connection to the EMS server.
Ø  In the absence of a durable subscriber or subscriber with a fault-tolerant connection, there are no subscribers that need messages resent in the event of a server failure. In this case, the server does not needlessly save persistent messages. This improves performance by eliminating the unnecessary disk I/O to persist the messages.



Ø  non-durable subscribers without a fault-tolerant connection that re-connect after a server failure are considered newly created subscribers and are not entitled to receive any messages created prior to the time they are created
Ø  Regardless of whether authorization is enabled or disabled, you can use the psend_check_mode parameter in the tibemsd.conf file to specify the conditions under which the server is to send confirmation of NON_PERSISTENT messages to the producer.
Ø  tibemsd.conf :  to set confirmation of NON_PERSISTENT messages to the producer
Ø  persistent messages received by the EMS server are by default written asynchronously to disk. This means that, when a producer sends a persistent message, the server does not wait for the write-to-disk operation to complete before returning control to the producer.
Ø  If server fails before completing the write-to-disk operation, the producer has no way of detecting the failure to persist the message and taking corrective action
Ø  Synchronous File Storage feature will block the producer until the server has completed the write-to-disk operation.
Ø  stores.conf file to specify that persistent messages for the topic or queue be synchronously written to disk. When mode = sync, the persistent producer remains blocked until the server has completed the write-to-disk operation.


















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