TIBCO EMS FAQ'S (Part 1)
http://tibcoemsonlinetraining.blogspot.com/2015/06/ems-faqs.html
1.What
are the different modes of installation in Ems ?
a. GUI mode
b. Console mode
c. Silent mode
2.What are the messaging models supported by JMS ?
a. Point-to-point
b. Publish-subscribe
c. Multicast
3.What are the destinations in EMS/JMS and their differences ?
Ans:
Queues: point-point communication. Any number of producers and consumers can exist. At any time and situation each message is taken by only one consumer.
Exclusive: only the first consumer who picks up the first message can take the rest of the messages (used if u wants only one consumer).
Non-exclusive: where any number of consumers can exist. Used for load balancing.
Topics: publish-subscribe.
Any number of publishers and subscribers can exist. Each message can be taken by any number of consumers (radio).
4.In how many ways can a destination be created ?
a. Static-created by user
b. Dynamic-created by ems server on the fly.
c. Temporary destinations.
5.Queues Vs Topics in TIBCO EMS ?
There are two major models for messaging supported by JMS: queues and topics. Queues are based on a point-to-point messaging model. Topics make use of the new publish-and-subscribe messaging model.
Regardless whether queues or topics are used, the messages are not sent directly peer-to-peer. Messages are forwarded to a JMS infrastructure that is composed of one or more JMS servers. The servers are responsible for providing the quality-of-services to JMS and responsible for implementing all the components not addressed by JMS Specification.
When determining when to use queues versus topics consider the two fundamental messaging mechanisms. The first is point-to-point messaging, in which a message is sent by one publisher (sender) and received by one subscriber (receiver). The second is publish-subscribe messaging, in which a message is sent by one or more publishers and received by one or more subscribers. The messaging model as listed below will dictate when to use a queue or a topic:
One-to-one messaging Queue point-to-point
One-to-many messaging Topic publish-subscribe
Many-to-many messaging Topic publish-subscribe model
6.what is
the Relationship between Temporary queue, queue, destination ?
A Destination can be a Queue or Topic, which typically says static. Which means you physically create this queue.
I hope you know the definition for Queue which can static, dynamic or temporary ?
Static represents physical creation.
Dynamic Represents, which will be created by receiver/sender application at run time, life span is limited, as long as there is messages or receivers, it will stay in server, if not it deletes.
Temporary Queue means, created by receiver to submit the response to EMS server or Sender to get the messages. this life span is immediate, but there is a hidden danger with these queues, as these might turn into orphan queues (please read other articles). there is a fix, which will go by 4.4.2 ems version
7.Difference between Exclusive and Non Exclusive Queues ?
you can define a queue as exclusive to make sure that all the messages are always sent to the same consumer, even if you have more than one connected to it. If you make it exclusive the rest of the consumers are "on standby" so if the primary fails another one is set as primary and starts receiving.
If you set them to non-exclusive (the default value) and you have more than one consumer connected to the queue the messages are delivered in a round robin fashion to balance the load.
8.What is the use of system queues ?
system queues are undeleteable queues stored usualy undelivered messages (when you set JMS_TIBCO_PRESERVE_UNDELIVERED to true, in case the message exipres, you'll get it to $sys.undelivered) or other even driven messages if applicable.
More in use are sytem topics for monitoring and statistics, where is EMS publishing queue and server statistics and can be detailed to message content level.
dead Queue
In case of any failures in the messages to server, will be added to dead queue, which is kind of internal system queue, I strongly feel.
For ex: No memory trying to add message to dead queue.
Failure queuing message to add to dead queue
9.How do we distinguish dynamic queues with static queues ?
dynamic queues have * before them.
10.what are the message storing mechanisms of queues ?
a. GUI mode
b. Console mode
c. Silent mode
2.What are the messaging models supported by JMS ?
a. Point-to-point
b. Publish-subscribe
c. Multicast
3.What are the destinations in EMS/JMS and their differences ?
Ans:
Queues: point-point communication. Any number of producers and consumers can exist. At any time and situation each message is taken by only one consumer.
Exclusive: only the first consumer who picks up the first message can take the rest of the messages (used if u wants only one consumer).
Non-exclusive: where any number of consumers can exist. Used for load balancing.
Topics: publish-subscribe.
Any number of publishers and subscribers can exist. Each message can be taken by any number of consumers (radio).
4.In how many ways can a destination be created ?
a. Static-created by user
b. Dynamic-created by ems server on the fly.
c. Temporary destinations.
5.Queues Vs Topics in TIBCO EMS ?
There are two major models for messaging supported by JMS: queues and topics. Queues are based on a point-to-point messaging model. Topics make use of the new publish-and-subscribe messaging model.
Regardless whether queues or topics are used, the messages are not sent directly peer-to-peer. Messages are forwarded to a JMS infrastructure that is composed of one or more JMS servers. The servers are responsible for providing the quality-of-services to JMS and responsible for implementing all the components not addressed by JMS Specification.
When determining when to use queues versus topics consider the two fundamental messaging mechanisms. The first is point-to-point messaging, in which a message is sent by one publisher (sender) and received by one subscriber (receiver). The second is publish-subscribe messaging, in which a message is sent by one or more publishers and received by one or more subscribers. The messaging model as listed below will dictate when to use a queue or a topic:
One-to-one messaging Queue point-to-point
One-to-many messaging Topic publish-subscribe
Many-to-many messaging Topic publish-subscribe model
A Destination can be a Queue or Topic, which typically says static. Which means you physically create this queue.
I hope you know the definition for Queue which can static, dynamic or temporary ?
Static represents physical creation.
Dynamic Represents, which will be created by receiver/sender application at run time, life span is limited, as long as there is messages or receivers, it will stay in server, if not it deletes.
Temporary Queue means, created by receiver to submit the response to EMS server or Sender to get the messages. this life span is immediate, but there is a hidden danger with these queues, as these might turn into orphan queues (please read other articles). there is a fix, which will go by 4.4.2 ems version
7.Difference between Exclusive and Non Exclusive Queues ?
you can define a queue as exclusive to make sure that all the messages are always sent to the same consumer, even if you have more than one connected to it. If you make it exclusive the rest of the consumers are "on standby" so if the primary fails another one is set as primary and starts receiving.
If you set them to non-exclusive (the default value) and you have more than one consumer connected to the queue the messages are delivered in a round robin fashion to balance the load.
8.What is the use of system queues ?
system queues are undeleteable queues stored usualy undelivered messages (when you set JMS_TIBCO_PRESERVE_UNDELIVERED to true, in case the message exipres, you'll get it to $sys.undelivered) or other even driven messages if applicable.
More in use are sytem topics for monitoring and statistics, where is EMS publishing queue and server statistics and can be detailed to message content level.
dead Queue
In case of any failures in the messages to server, will be added to dead queue, which is kind of internal system queue, I strongly feel.
For ex: No memory trying to add message to dead queue.
Failure queuing message to add to dead queue
9.How do we distinguish dynamic queues with static queues ?
dynamic queues have * before them.
10.what are the message storing mechanisms of queues ?
persistent and non-persistent.
Persistent: messages are stored to external storage before sending.
Non-persistent: not stored to any external storage. The information will not be available for retrieval.
11.what are types of subscribers we can have for topics ? Explain them in detail ?
Persistent: messages are stored to external storage before sending.
Non-persistent: not stored to any external storage. The information will not be available for retrieval.
11.what are types of subscribers we can have for topics ? Explain them in detail ?
durable and non-durable subscribers.
In durable subscriptions the messages are stored so that even if the subscriber fails and comes back the messages can be retrieved.
12.What are the permissions that you can grant to users to access queues ?
a. Receive
b. Send
c. Browse
13.What are the permissions that you can grant to users to access topics ?
a. Subscribe
b. Publish
c. Durable
d. Use_durable
In durable subscriptions the messages are stored so that even if the subscriber fails and comes back the messages can be retrieved.
12.What are the permissions that you can grant to users to access queues ?
a. Receive
b. Send
c. Browse
13.What are the permissions that you can grant to users to access topics ?
a. Subscribe
b. Publish
c. Durable
d. Use_durable
