TIBCO EMS FAQ -1

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1)       What are the two storage methods used by Tibco EMS server?
Ans) File based and database
2)      What files are created in file based data storage method?
Ans) sync.db,async.db,meta.db
3)       What information does Meta.db contain?
Ans) durable subscribers, fault tolerant connections and other Meta data.
4)      What does flow control property specifies?
Ans) specifies the maximum size of the pending messages in server.
5)       What are the destinations of messages?
Ans) topics and queues.
6)      How many ways destinations for messages can be created?
Ans)  static: administrator creates destinations and client programs use the destinations
Dynamic: here client program creates destinations during runtime
Temporary: servers connected through routes communicate through temporary destinations.
7)      What are the messaging models supported by ems server?
Ans) point to point (queues), pub/sub (topics), and multicast (topic).
8)      What is the diff between exclusive queues and non exclusives?
9)      How long the message will be stored for durable subscribers?
Ans) as long as durable subscriber exists or until msg expiration time reached or storage limit has been reached.
10)  What are the different delivery modes supported by ems?
Ans) Persistent, non Persistent and Reliable.
11)  What is the advantage of reliable mode delivery?
12)  What is the condition for persistent message to be stored on disk in topics?
Ans) there must be at least one durable subscriber or one non durable subscriber must be connected to fault tolerant connection to ems server.
13)  How do you distinguish dynamic queues and static queues?
Ans) dynamic queues have * before the queue name.
14)  What happens if npsend_checkmode parameter in tibemsd.conf file is enabled?
Ans) Server sends acknowledgement for non persistent message.
15)  What is shared state in fault tolerant operation?
Ans) primary server and backup server have connection to shared state which contains information about client connection and persistent messages.
16)  How many ways a backup server detects failure of primary server?
Ans) Heartbeat failure:-Primary server sends a heartbeat message to backup server to indicate primary server is working.
Connection failure:-backup server detects the failure of tcp connection with primary server.
17)  What is the use of locking in fault tolerant operation?
Ans)In order to prevent the backup server to take the role of primary server, the primary server logs the shared state in normal operation and during the failure of primary server backup server takes the lock and access primary server.
18)  If authorization is enabled in tibemsd.config file what is the condition to configure ems server as fault tolerance?
Ans)Server name and password for both primary and backup server should be same and username and password for both servers should match the server and password parameters in tibemsd.config file.
19)  What are the changes to be made in config file for ems fault tolerant operation?
Ans)In primary server give url of backup server to ft_active parameter and in backup server give url of primary server for ft_active parameter.
20)   Different types of zones?
Ans) Multihop zone and 1hop zone.
21)  What is fail safe?
Ans)In fail safe mode messages are first stored in disk before sending messages so that no messages are lost.
22)  What is the default port number for ems server?
Ans) 7222.
23)  Difference between rendezvous and ems?
Ans) Rvd is bus based architecture, ems is centralized architecture.
24)  What are different acknowledge modes?
Ans. Dups_ok_acknowlwdge,auto_acknowlwdge,client_acknowledge,no_acknowledge.
25)  How many ways we can determine the life span of the message in a queue. What are they?
Ans) expiration parameter in queue configuration file.
JMS expiration time in queue sender.
The JMS expiration time in queue sender overrides any value given in config.
26)  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.
27)  What is condition to create bridge?
Ans) Queues and topics must be defined as global.
28)   Why do we need routers?
Ans) To transfer messages between different ems servers.
29)  What is the default maximum size of message?
Ans. 512mb.
30)  How do you configure client for fault tolerant connection?
Ans) Specify multiple server as a comma-separated list of URLs and both URLs must use same protocol either tcp or ssl. 




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