EMS Interview Questions

8/8/2019 EMS Interview Questions

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EMS interview questions on: March 12, 2009, 03:16:45 PM

These are some of the sample interview questions on EMS..

1. What are the different types of acknowledgement modes in EMS

message delivery

Auto

Client

Dups_ok

No_ack

Explciit

Explicit_client_dups_ok

Transitional Local transitional.

2. What are the different types of messages that can be used in EMS

Text

Simple

Bytes

Map

XML test

Object

Object ref Stream

3. Tell me about bridges. Why do we use them, Syntax to create bridges,

use of message selector

Some applications require the same message to be sent to more than one

destination possibly of different types. So we use bridges.

4. What is the purpose for stores.conf

a. This file defines the locations either store files or a database, where the

EMS server will store messages or metadata.

b. Each store configured is either a file-based or a database store.

5. How many modes are the messages written to store file.

2 modes.. sync or async. When absent , the default is async
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6. What is tibemsd.conf

It is the main configuration file that controls the characteristics of the EMS

server

7. How many delivery modes for messages?

Persistent, Non-persistent, Reliable-delivery.

8. What is the maximum messagesize?

Ems supports max message size of 512 mb

9. Name 3 destination properties and explain them.

Global, secure, maxmsgs, maxbytes, flowcontrol, sender_name,

sender_name_enforced, trace,maxRedelivery

10. What are the different modes of installation in Ems?

a. GUI mode

b. Console mode

c. Silent mode

11. What are the messaging models supported by JMS

a. Point-to-point

b. Publish-subscribe

c. Multicast

12. Tell me about routes

What is the purpose of routes, what kind of destinations can be used in

routes? Topics and queues m-hops

13. 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.


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14. 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.

15. What are the wild cards that we use in ems?how do they work for

queues and topics

*,>

U can subscribe to wildcard topics but cant publish to them. Where as in

case of queues we cant either send /receive.

16. Are bridges transitive?

NO

17. Tell me about flow control on destinations

Some times 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.

18. Tell me about flow control on bridges and routes

Flow control has to be specified on both sides of bridges where as onroutes it operates differently on sender side and receiver side.

19. Name 3 configuration files and tell me what it consists of

a. Queues.conf

b. Topics.conf

c. Routes.conf

d. Factories.conf

e. Stores.conf

f. Groups.conf,users.conf,transports.conf

20. Name some administrative level destination properties

a. View

b. Create

c. Delete


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d. Modify

e. Purge

21. How can you change the configuration properties of EMS server

You can change in the tibemsd.conf file or you can change using the ems

admin console.

22. What are the permissions that you can grant to users to access queues

a. Receive

b. Send

c. Browse

23. What are the permissions that you can grant to users to access topics

a. Subscribe

b. Publish

c. Durable

d. Use_durable

24. 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 eachconsumer. EMS uses Pragmatic general multicast to broadcast messages

published to multicast enabled topics.

b. Each multicast enabled topic is associated with a channel.

25. 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 cant be used to sendmessages between servers.

26. On what destinations can you use multicast?

a. Topics


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27. Suppose, you got an error while accessing a queue, that you dont have

necessary permissions to access the queue. What might be the

solution/reason?

a. The user that is assigned to the queue and the user used while creating

28. How does the secondary server know that the primary server is failed?

a. Based on heartbeat intervals

29. What is JMS queue requestor?

a. 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

30. What is JMS topic requestor?

a. The JMS Topic Requestor activity is used to communicate with a JMS

applications 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.

31. How do you add ems server to administrator?

a. Using domain utility

32. How do you remove individual messages from destinations?

a. Using purge command.

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EMS Interview Questions