TIBCO EMS FAQ -3
61) How do you add ems server to administrator?
Ans) a. using domain utility.
62) How do you remove individual messages from destinations?
Ans) a. Using purge command.
63) What is the purpose of JMS Queue receiver activity and Queue sender activity?
Ans: Starts a process when ever a new message comes into the specified queue.
A queue sender activity sends messages into the specified queue.
64) 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 received.
• Client — the message will be acknowledged at a later point by using the Confirm activity. If the message is not confirmed before the process instance ends, the message is redelivered and a new process instance is created to handle the new incoming message. Ensure that your process definition confirms the message when using this acknowledge mode.
• TIBCO EMS Explicit Client Acknowledge — this mode behaves exactly the same as the Client mode, except the session is not blocked and one session can handle all incoming messages.
• Dups OK — the message is acknowledged automatically when it is received. JMS provides this mode for lazy acknowledgement, but TIBCO BusinessWorks acknowledges messages upon receipt.
• Transactional — this mode is used when a transaction that can process JMS messages is included in the process definition. The message is acknowledged when the transaction commits. See TIBCO Business Works Process Design Guide for more information about creating transactions that JMS activities can participate in.
65) What is the potential problem with JMS Queue requestor?
Ans) When we specify a reply to queue there is a chance of other processes sending messages to the same queue and the jms queue requestor interpreting that as the actual response and sending this wrong message to the client.
66) What is the other JMS activity you would use to address the problem?
Ans) Get jms queue message. This incorporates a message ID to identify the true message.
67) What are the activities you used to publish the messages from BW process to network on RV?
Ans: publish rv message activity (along with the shared resource – rv transport).
68) Why are routes used?
a. When we have to send messages from one server to another.
69) What parameters would be used to control storage in EMS?
a. Flow control property.
70) What are the diff types of messaging services in RV?
a. RV
b. RVCM
c. RVCMQ
d. RVRD.
71) Which transport is used between hawk agent and hawk micro agent?
Rv
72) What re the three transport types available when configuring a tibco component?
Http, RV,local.
73) How is reduce the load on ems server?
Using maxbytes, flow limit, prefetch mechanisms.
74) What is the difference between RVD and RVRD
a. RVD is used to route with in a subnet
b. RVRD is used to route through different subnet.
75) What are message selectors?
a. Message selectors are used to filter messages based on expression syntax. This reduces the processing overhead from the application.
76) What is a Home Queue and what is a Routed Queue in EMS routes?
a. Home Queue: The global queue sitting in the EMS server, where Route is being created.
b. Routed Queue: the global queue sitting in the EMS server where the queue name is referring to route.
77) What is the EMS maximum message size?
a. The maximum message size is 512 MB.
78) What are the wildcard characters supported by EMS?
a. * – means that any token can be in place of *.
b. > – matches any destination name i.e., it matches one or more trailing elements.
You can subscribe to wildcard topics but can’t publish.
You can neither send nor receive from wildcard queue names
79) What is the default storage limit for destinations?
a. Setting the flowControl property on a destination but specifying no value causes the server to use a default value of 256KB.
80) What is the syntax to create bridges?
a. Create bridge bridge_name source=destination_type:name target=destination_type:name
81) How do avoid/stop creation of dynamic queues/topics?
a. By deleting the parent queue “>”.
82) How is load balancing done in Rendezvous?
Using distributed queues
83) What protocol does RV uses to communicate with in a subnet and outside the subnet?
UDP within a subnet
TCP outside subnet.
84) What is the use of secured queues and topics?
a. Setting ‘secure’ property to queues/topics can restrict unauthorized users from publishing/sending and subscribing/receiving the messages.
85) Tell me about multicasting in EMS?
a. Multicast is a messaging model that broadcasts messages to many consumers at once rather than sending messages individually to each consumer. EMS uses Pragmatic general multicast to broadcast messages published to multicast enabled topics.
b. Each multicast enabled topic is associated with a channel.
86) What are the advantages and disadvantages of multicasting?
a. Advantages: as the message broadcasts only once thereby reducing the amount of bandwidth used in publish and subscribe model. Reduces the network traffic.
b. Disadvantages: Offers only last-hop delivery. So can’t be used to send messages between servers.
87) On what destinations can you use multicast?
Topics
88) Suppose, you got an error while accessing a queue, that you don’t have necessary permissions to access the queue. What might be the solution/reason?
The user that is assigned to the queue and the user used while creating
89) How does the secondary server know that the primary server is failed?
Based on heartbeat intervals
90) What is JMS queue requestor?
The JMS Queue Requestor activity is used to send a request to a JMS queue name and receive a response back from the JMS client.
91) How do you add ems server to administrator?
Using domain utility
92) How do you remove individual messages from destinations?
Using purge command.
93) What is JMS topic requestor?
The JMS Topic Requestor activity is used to communicate with a JMS application’s request-response service. This service invokes an operation with input and output. The request is sent to a JMS topic and the JMS application returns the response to the request.
94) 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
95) What is the Relationship between Temporary queue, queue, and 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
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.
96) 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
97) How do we distinguish dynamic queues with static queues?
Ans: dynamic queues have * before them.
98) What are the message storing mechanisms of queues?
Ans: 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.
99) What are types of subscribers we can have for topics? Explain them in detail?
Ans: 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.
100) What are the permissions that you can grant to users to access queues?
a. Receive
b. Send
c. Browse
Ans) a. using domain utility.
62) How do you remove individual messages from destinations?
Ans) a. Using purge command.
63) What is the purpose of JMS Queue receiver activity and Queue sender activity?
Ans: Starts a process when ever a new message comes into the specified queue.
A queue sender activity sends messages into the specified queue.
64) 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 received.
• Client — the message will be acknowledged at a later point by using the Confirm activity. If the message is not confirmed before the process instance ends, the message is redelivered and a new process instance is created to handle the new incoming message. Ensure that your process definition confirms the message when using this acknowledge mode.
• TIBCO EMS Explicit Client Acknowledge — this mode behaves exactly the same as the Client mode, except the session is not blocked and one session can handle all incoming messages.
• Dups OK — the message is acknowledged automatically when it is received. JMS provides this mode for lazy acknowledgement, but TIBCO BusinessWorks acknowledges messages upon receipt.
• Transactional — this mode is used when a transaction that can process JMS messages is included in the process definition. The message is acknowledged when the transaction commits. See TIBCO Business Works Process Design Guide for more information about creating transactions that JMS activities can participate in.
65) What is the potential problem with JMS Queue requestor?
Ans) When we specify a reply to queue there is a chance of other processes sending messages to the same queue and the jms queue requestor interpreting that as the actual response and sending this wrong message to the client.
66) What is the other JMS activity you would use to address the problem?
Ans) Get jms queue message. This incorporates a message ID to identify the true message.
67) What are the activities you used to publish the messages from BW process to network on RV?
Ans: publish rv message activity (along with the shared resource – rv transport).
68) Why are routes used?
a. When we have to send messages from one server to another.
69) What parameters would be used to control storage in EMS?
a. Flow control property.
70) What are the diff types of messaging services in RV?
a. RV
b. RVCM
c. RVCMQ
d. RVRD.
71) Which transport is used between hawk agent and hawk micro agent?
Rv
72) What re the three transport types available when configuring a tibco component?
Http, RV,local.
73) How is reduce the load on ems server?
Using maxbytes, flow limit, prefetch mechanisms.
74) What is the difference between RVD and RVRD
a. RVD is used to route with in a subnet
b. RVRD is used to route through different subnet.
75) What are message selectors?
a. Message selectors are used to filter messages based on expression syntax. This reduces the processing overhead from the application.
76) What is a Home Queue and what is a Routed Queue in EMS routes?
a. Home Queue: The global queue sitting in the EMS server, where Route is being created.
b. Routed Queue: the global queue sitting in the EMS server where the queue name is referring to route.
77) What is the EMS maximum message size?
a. The maximum message size is 512 MB.
78) What are the wildcard characters supported by EMS?
a. * – means that any token can be in place of *.
b. > – matches any destination name i.e., it matches one or more trailing elements.
You can subscribe to wildcard topics but can’t publish.
You can neither send nor receive from wildcard queue names
79) What is the default storage limit for destinations?
a. Setting the flowControl property on a destination but specifying no value causes the server to use a default value of 256KB.
80) What is the syntax to create bridges?
a. Create bridge bridge_name source=destination_type:name target=destination_type:name
81) How do avoid/stop creation of dynamic queues/topics?
a. By deleting the parent queue “>”.
82) How is load balancing done in Rendezvous?
Using distributed queues
83) What protocol does RV uses to communicate with in a subnet and outside the subnet?
UDP within a subnet
TCP outside subnet.
84) What is the use of secured queues and topics?
a. Setting ‘secure’ property to queues/topics can restrict unauthorized users from publishing/sending and subscribing/receiving the messages.
85) Tell me about multicasting in EMS?
a. Multicast is a messaging model that broadcasts messages to many consumers at once rather than sending messages individually to each consumer. EMS uses Pragmatic general multicast to broadcast messages published to multicast enabled topics.
b. Each multicast enabled topic is associated with a channel.
86) What are the advantages and disadvantages of multicasting?
a. Advantages: as the message broadcasts only once thereby reducing the amount of bandwidth used in publish and subscribe model. Reduces the network traffic.
b. Disadvantages: Offers only last-hop delivery. So can’t be used to send messages between servers.
87) On what destinations can you use multicast?
Topics
88) Suppose, you got an error while accessing a queue, that you don’t have necessary permissions to access the queue. What might be the solution/reason?
The user that is assigned to the queue and the user used while creating
89) How does the secondary server know that the primary server is failed?
Based on heartbeat intervals
90) What is JMS queue requestor?
The JMS Queue Requestor activity is used to send a request to a JMS queue name and receive a response back from the JMS client.
91) How do you add ems server to administrator?
Using domain utility
92) How do you remove individual messages from destinations?
Using purge command.
93) What is JMS topic requestor?
The JMS Topic Requestor activity is used to communicate with a JMS application’s request-response service. This service invokes an operation with input and output. The request is sent to a JMS topic and the JMS application returns the response to the request.
94) 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
95) What is the Relationship between Temporary queue, queue, and 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
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.
96) 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
97) How do we distinguish dynamic queues with static queues?
Ans: dynamic queues have * before them.
98) What are the message storing mechanisms of queues?
Ans: 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.
99) What are types of subscribers we can have for topics? Explain them in detail?
Ans: 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.
100) What are the permissions that you can grant to users to access queues?
a. Receive
b. Send
c. Browse
Comments
Post a Comment