Tibco EMS

EMS Destination Properties


EMS Destination Properties

 In this Tibco EMS tutorial we will understand different EMS destination properties.

Secure


Authenticate users before giving access to a queue or topic. Only authenticated users can send or receive message from the secured destination.

Syntax: addprop [queue|topic] <<queue|topic name>> secure
Example: addprop topic topic.foo secure

Channel


Setting this property make a topic multicast. This property can be only set to a topic by which messages send to these topics are broadcasted.

Syntax: <<topic name>> channel=<<channel name>>

Example: topic.foo channel=mycast
Channels configuration details are stored in channels.conf

Exclusive


[Only for queue] By default the EMS server send the messages on a queue to the consumers in a round-robin fashion. By setting this property the message on the queue are send to only one consumer (Primary) and other consumers (Secondary) on the same queue are at standby.

If the primary consumer fails the standby consumer becomes primary.
This property can not be set to a topic or a global queue.
Exclusive property can be in case of fault tolerance
mode at consumer end.
Example: create queue.foo exclusive

Expiration


The messages are destroyed or send to the undelivered queue if the message in not consumed within the time specified.
Syntax: setprop queue <<queue name>> expiration=time[msec|sec|min|hour|day]
Example: setprop queue foo expiration=10min

Flowcontrol


Server slows down the producers to the rate at which the consumer is receiving it if the specified max size used to store pending messages exceeds.
Syntax: setprop queue <<queue name>> flowcontrol=size[KB|MB|GB]
Example: setprop queue foo flowcontrol=10MB

MaxBytes and MaxMsg


Max size to store overall message in a queue or topic. Message are rejected on exceeding.
MaxBytes:

Syntax: setprop queue <<queue name>> maxbyte=size[KB|MB|GB]
Example: setprop queue foo maxbyte=10MB

MaxMsg:
Syntax: setprop queue <<queue name>> maxmsg=number
Example: setprop queue foo maxmsg=1000

Overflow Policy


Used to change the effect of max bytes and max message on exceeding the specified limit.

Properties that can be assigned:
Default:
For topics, default specifies if the maxbytes or maxmsgs setting has been reached, then that subscriber does not receive the message. No error is returned to the message producer.
For queues, default specifies that new messages are rejected by the server and an error is returned to the producer if the established maxbytes or maxmsgs value has been exceeded.

Discard Old: For queue and topic the oldest messages are discarded before they are delivered to the subscriber/consumer.
An error message is send to the producer incase of queue [EMS 6.0].
No error message is send to the producer in case of queue or topic [EMS 7.0].

Reject Incoming: For queue and topic the new messages are discarded before they are delivered to the subscriber/consumer and error message is send to the to the producer.

Trace


Enables tracing for a destination.

Syntax: addprop [queue|topic] <<queue|topic name>> trace
Example: addprop topic topic.foo trace

Import


Allows messages published by an external system to be
received by a EMS destination (a topic or a queue), as long as the transport to the external system is configured.

Export


Allows messages published by a client to a topic to be exported to the external systems with configured transports.


About Varun Goel

Varun Goel is a technology enthusiast with 6+ years exp in IT industry. In fact, he is been developing application after schooling as freelancer. Currently working with one of the Fortune’s 100 Companies having vast experience Mule ESB, Tibco, HTML5, CSS, JSS, Android, Core Java, JSP, PHP, MySQL, AutoCAD, Maya, ZBrush, Photoshop, Flash CS and many more.

2 comments

  1. Marc Aussems

    Hi, from the EMS 7.0 manual regarding discardOld:

    discardOld
    For topics, discardOld specifies that, if any of the subscribers have an
    outstanding number of undelivered messages on the server that are over the
    message limit, the oldest messages are discarded before they are delivered to the
    subscriber.
    The discardOld setting impacts subscribers individually. For example, you might
    have three subscribers to a topic, but only one subscriber exceeds the message
    limit. In this case, only the oldest messages for the one subscriber are discarded,
    while the other two subscribers continue to receive all of their messages.
    When messages for a topic or queue exceed the maxbytes or maxmsgs value, the
    oldest messages are silently discarded. No error is returned to the producer.

    –> It states that ‘No error is returned to the producer’ where on your site it states that an error is sent to the producer. Quite a difference

    1. Varun Goel Post author

      Thanks for pointing that out. The point for discardOld mentioned referred to EMS 6.0 doc. Also, I have made the correction on my post for the same.

Leave a Reply

Your email address will not be published.