CLIENT_ACKNOWLEDGE and AUTO_ACKNOWLEDGE and DUPS_OK_ACKNOWLEDGE?

-

Ø  CLIENT_ACKNOWLEDGE specifies that the consumer is to acknowledge all messages that have been delivered so far by the session. When using this mode, it is possible for a consumer to fall behind in its message processing and build up a large number of unacknowledged messages.
Ø  AUTO_ACKNOWLEDGE specifies that the session is to automatically acknowledge consumer receipt of messages when message processing has finished.
Ø  DUPS_OK_ACKNOWLEDGE specifies that the session is to "lazily" acknowledge the delivery of messages to the consumer. "Lazy" means that the consumer can delay acknowledgement of messages to the server until a convenient time.
Ø  EMS extends the JMS session modes to include:
Ø  NO_ACKNOWLEDGE mode suppresses the acknowledgement of   received messages
Ø  EXPLICIT_CLIENT_ACKNOWLEDGE is like CLIENT_ACKNOWLEDGE except it acknowledges only the individual message, rather than all messages received so far on the session
Ø  EXPLICIT_CLIENT_DUPS_OK_ACKNOWLEDGE is like DUPS_OK_ACKNOWLEDGE except it ’lazily" acknowledges only the individual message, rather than all messages received so far on the session
Ø  TIBCO Enterprise Message Service supports two modes of sending messages
Ø  Synchronous
Ø  Asynchronous

Comments

Post a Comment

Popular posts from this blog

TIBCO EMS FAQ -5

-
131) What happens if the message expires/exceeded the value specified by maxredelivery property on queue? If the jms_preserve_undelivered property is set to true, then it moves he message to undelivered message queue, if set to false, the message is deleted by the server. 132) What are the wild cards that we use in ems?how do they work for queues and topics? *,> We can subscribe to wildcard topics, but cant publish to them. Where as in case of queues we can’t either send /receive. 133) Are bridges transitive? No 134) Tell me about flow control on destinations? Sometimes the producer may send messages faster than the consumers can receive them. So, the message capacity on the server will be exhausted. So we use flow control. Flow control can be specified on destinations. 135) Tell me about flow control on bridges and routes? Flow control has to be specified on both sides of bridges where as on routes it operates differently on sender side and receiver side. 136) Nam...
Read more

TIBCO EMS FAQ -4

-
101) What are the permissions that you can grant to users to access topics? a. Subscribe b. Publish c. Durable d. Use durable 102) What is the difference between Queues and Topics? Queue • Guaranteed Service • Only the Target gets the message (One message per Consumer) • Uses Peer-to-Peer Mode to deliver messages • Blocking • Load Balancing is possible Topic • Reliable Service • Everyone active gets the message (One message may Consumers) • Uses Pub / Sub mode to deliver messages • Non-Blocking • Load Balancing is not possible. 103) What is the use of secured queues and topics? Setting ‘secure’ property to queues/topics can restrict unauthorized users from publishing/sending and subscribing/receiving the messages. 104) What are acknowledgement modes and where do you set them and what is the applicability of each mode? Ans:The acknowledge mode for incoming messages. Can be one of the following: • Auto — the message is automatically acknowledged when it is re...
Read more

TIBCO BW FAQ -2

-
31) What happens if you use check point activity first and confirm next? Ans)In the case of confirmable messages , you must consider the consequences of performing a checkpoint before or after a Confirm activity. If the checkpoint is taken before the Confirm activity, then a crash occurs after a checkpoint but before a confirm, the original message is resent. In this case, the restarted process can no longer send the confirmation. However, a new process is started to handle the resent message, and you can implement your process to handle the restarted and new processes appropriately. If the checkpoint is taken after a Confirm activity, there is potential for a crash to occur after the Confirm but before the checkpoint. In this case, the message is confirmed and therefore not redelivered. The process instance is not restarted, because the crash occurred before the checkpoint. You must consider the type of processing your process definition performs to determine when a checkpoint i...
Read more