TIBCO EMS Faq's
What are the different modes of
installation in Ems?
- GUI mode
- Console mode
- Silent mode
What are the messaging models
supported by JMS?
- Point-to-point
- Publish-subscribe
- Multicast
What are the destinations in EMS/JMS and their differences?
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).
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).
In how many ways
can a destination be created?
Static-created
by user
Dynamic-created
by ems server on the fly.
Temporary
destinations.
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
What is the use of system queues?
Durable and Non-Durable subscribers.
What are the basic configuration you would set-up if you want to enable your EMS server for SS l communication
delete bridge source=queue:bridgequeue target=topic:bridgetopic
1.Make a duplicate copy of the “cfgmgmt” Folder and rename it to “cfgmgmt2”
2.Make sure that the Server Name is NOT the same in the “tibemsd.conf” file in both the folders.
3.Change the port number in the second folder’s “tibemsd.conf” file (listen = tcp://xxxx)
4.Set the routing property to enabled in the “tibemsd.conf” files in both the folders open factories.conf under
“cfgmgmt2” and change the settings for General Connection Factory, Queue Connection Factory and opicConnectionFactory URL to (tcp://xxxx)
5.Create Route on Server 1 (route “Server2-Name” url=tcp://localhost:xxxx)
6.Create global queue / topics on both servers as required
7.Start both copies of the servers from the command prompt (ex: C:\ .. \ems\5.1\bin\tibemsd –config
“C:\ .. \cfgmgmt\ems\data\tibemsd.conf”)
8.Test the route by using queue / topic in a BW Process
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
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.
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.
What is 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
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
How do we distinguish dynamic queues with static queues?
Dynamic
queues have * before them.
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.
What are the permissions that you can grant to users to
access queues?
a. Receive
b. Send
c. Browse
What are the permissions that you can grant to users to
access topics?
a. Subscribe
b. Publish
c. Durable
d. Use durable
b. Publish
c. Durable
d. Use durable
What is the use of secured queues and topics?
Setting secure property to queues/topics can restrict unauthorized users from publishing/sending and subscribing/receiving the messages.
What are acknowledgement modes and where do you set them and what is the applicability of each mode?
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 confirmedbefore the process instance ends, the message is redelivered and a new process instance iscreated 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 notblocked 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.
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 confirmedbefore the process instance ends, the message is redelivered and a new process instance iscreated 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 notblocked 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.
what is the structure of messages in JMS?
1. header(needed),
2.properties(optional)
3.body(optional).
4.Header parameters:
5.JMS destination,
6.JMS message.
What
is the purpose of JMS Queue receiver activity and Queue sender activity?
Starts a
process when ever a new message comes into the specified queue.A queue sender activity sends messages into the
specified queue.
What
is the potential problem with JMS Queue requestor?
When we
specify a reply to queue there is a chance of other processes sending messages
to the same queueand the jms queue requestor interpreting that
as the actual response and sending this wrong message to the client.
How
to set-up load balancing for Topics and queues?
We can achieve load balancing using bridging queues and topics.Or Queues can be set non-exclusive so that any number of consumers can access the queue.
What are the different levels of load balancing in EMS and how would you do it?
server level and consumer level
Server : by having multiple servers.
Consumer: by creating consumer instances.
server level and consumer level
Server : by having multiple servers.
Consumer: by creating consumer instances.
What are the differences between server load balancing & producer/consumer load balancing?
Point-to-Point : Non-exclusive queues are useful for balancing the load of incoming messages across multiple receivers.
Programs can use distributed queues for one-of-n certified delivery to a group of servers, in order to balance the load among the servers.
Rendezvous distributed queue software assigns each task to exactly one of the servers, while the group of servers and the distribution of tasks remains completely transparent to the client processes.
EMS Load balancing can be done in only one way on the consumer side, by using multiple subscribers/receivers to a same topic/queue, and which will be executed in round robin fashion. If we are connecting two different severs by using "|" symbol is not be load balancing,Consumers can not switch connections between two servers. By default, we will implement multiple consumers but we have to consider above mentioned issues in consumer load balancing.
Point-to-Point : Non-exclusive queues are useful for balancing the load of incoming messages across multiple receivers.
Programs can use distributed queues for one-of-n certified delivery to a group of servers, in order to balance the load among the servers.
Rendezvous distributed queue software assigns each task to exactly one of the servers, while the group of servers and the distribution of tasks remains completely transparent to the client processes.
EMS Load balancing can be done in only one way on the consumer side, by using multiple subscribers/receivers to a same topic/queue, and which will be executed in round robin fashion. If we are connecting two different severs by using "|" symbol is not be load balancing,Consumers can not switch connections between two servers. By default, we will implement multiple consumers but we have to consider above mentioned issues in consumer load balancing.
How
would you do fault-tolerance in EMS? Explain the complete process.
FT in
EMS can be achieved by implementing pair of servers called primary and backup
while the primary does the normal job of sending and receiving messages the
back up server takes the place of primary if the primary fails. The pair shares
the information from the shared state. When the primary goes down the backup
server reads all the primary config files and starts from there. The primary
locks the shared state if its active so that the backup server doesn’t take its
place. the lock is released when the primary goes down so that the backup can
lock the shared state. Only persistent messages can be implemented in this
situation since non-persistent messages cannot be stored in external storage
like shared state.
How
a consumer can connect to the new primary EMS server when the running primary
server goes down?
When we
specify a reply to queue there is a chance of other processes sending messages
to the same queue and the ems queue requester interpreting that as the actual response and sending this wrong message to the client.
How
a consumer can connect to the new primary EMS server when the running primary
server goes down?
we can
specify multiple URL’S for the client so that if the primary is down the next
URL belonging to back up will be used.In case of a primary having multiple address we
can use multiple URL’S for the same server so that even the primary in one
location is down it can connect to the primary of another location.The URL’S are usually comma separated in client
config.
How
the clients of the primary server access the messages stored by primary server
when it goes down and secondary server becomes primary server?
clients
can be config to be intimated of the fail over.
The backup reads the current state of the
client from the shared storage
And then connects to the client if there are
any undelivered persistent messages.
Scenario: Topic T1, Queue Q1 and Queue Q3 are bridged. A
publisher published a message to Topic T1. But the publisher has no access
rights to Q1. How the message will be traversed?
Message
producers must have access to a destination in order to send messages to that destination. Messages can only be sent to bridged destinations to which the
message producer has access.
Scenario: A publisher is publishing messages quickly
than the consumers are consuming the messages. How to control this situation.
We can
use flow control to address this situation. The target maximum size for pending
messages is specified so that only that amount of message is stored and any
messages above that will be blocked.
The server blocks the send call and releases
only when the storage limit is below the set value.
The flow control is enabled only if the topic
or queue has receivers.
This way the producers are slowed down. And the
balance is achieved.
Can
we set a limit for the total number of pending messages on Queue or Topic? What
is the parameter ?
yes, max-bytes for pending messages.
What
if max-bytes limit exceeds?
Messages
that would exceed the limit will not be accepted into storage and an error is
returned to the message producer.
What
is the pre-fetch value?
In order
for reducing the client’s waiting time in a server client scenario
For a queue based messaging only the prefetch
value allows the the server to send messages in batches so that the message
will be ready for the client when ever the client is ready. For automatic
fetching its >1 and for disabling its “none”.
What
is fail-safe?
The
Tibco ems provides 2 modes for persistent topic/queue message storing to
external device.
Normal: in this mode the messages stay in a
buffer before writing to a storage(disk). So in case of any failure the
messages may be lost.This mode is very efficient in situations were little loss
of data is allowed.
Fail-safe:
in the fail safe mode the messages are first written to an external storage
before sending so that no messages are lost ever. This is used when no loss of
data can be encouraged.
How
many ways we can determine the life span of the message in a queue. What are they?
- EMS expiration time in queue sender.
- The EMS expiration time in queue sender overrides any value given in config.
What are the basic configuration you would set-up if you want to enable your EMS server for SS l communication
listen parameter and ss l_server_identity. Optionally private key
What
is the main config file in EMS?
The main
configuration file controls the characteristics of the TIBCO Enterprise Message
Service server. This file is usually named tibemsd.conf, but you can specify
another file name when starting the server.
Exp
para: server, password,flow control,storage,server start-up…
Can
you send messages from a server to another server?
TIBCO Enterprise Message Service servers can
route messages to other servers.
• Topic messages can travel one hop or multiple
hops(from the first server).
• Queue messages can travel only one hop to the
home queue, and one hop from the home queue.
A
server forwards topic messages along routes only when the global property is
defined for the topic.
When a route becomes disconnected (for example,
because of network problems), the forwarding server stores topic messages. When
the route reconnects, the server forwards the stored messages.
What
are multi-hop zone?
Multi-hop zone is a group of servers connected
by routes.
How
do you configure multi-hop zones?
By
using routes:
To create a route using the administration
tool, first connect to one of the servers, then use the create route command
with the following syntax:
create route url= zone_name=
zone_type=1hop|mhop
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.
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.
How
many modes are the messages written to store file.
2 modes.. sync or async. When absent , the default is async
What
is tibemsd.conf
It is the main configuration file that controls
the characteristics of the EMS server.
How
many delivery modes for messages?
Persistent, Non-persistent, Reliable-delivery.
What
is the maximum message size?
Ems supports max message size of 512
Name
3 destination properties and explain them.
Global,secure,maxims,megabytes,flowcontrol,sender_name,sender_name_enforced, trace,
max Redelivery
log_trace
"Log_Trace" writes information to the specified log file based on the trace options
log trace will be written to log file.
Console_trace
Console Trace will be useful when you start your server in common window, and all logs will be displayed there, and of course it written to log files also when you configure it.
max Redelivery
log_trace
"Log_Trace" writes information to the specified log file based on the trace options
log trace will be written to log file.
Console_trace
Console Trace will be useful when you start your server in common window, and all logs will be displayed there, and of course it written to log files also when you configure it.
What
happens if the message expires/exceeded the value specified by redelivery property on queue?
If the ems_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.
What
are the wild cards that we use in ems?how do they work for queues and topics?
*,>
We can subscribe to wildcard topics, but cant
publish to them. Where as in case of queues we can’t either send /receive.
Are
bridges transitive?
NO
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.
Tell
me about flow control on bridges and routes?
Flow control has to be specified on both sides of bridges where as on routes it operates differently on sender side and receiver side.
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
Name
some administrative level destination properties?
a. View
b. Create
c. Delete
d. Modify
e. Purge
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.
Tell
me about multi casting 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.
b. Each multicast enabled topic is associated with a channel.
What
are the advantages and disadvantages of multicasting..
a. Advantages: As the message broadcasts only
once there by 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.
On
what destinations can you use multicast?
Topics
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.
How
does the secondary server know that the primary server is failed?
Based on heartbeat intervals
How
do you add ems server to administrator?
Using domain utility
How
do you remove individual messages from destinations?
Using purge command.
Connection and Session threading in Ems
Connection : Multi thread
Session : Single thread
Connection and Session threading in Ems
Connection : Multi thread
Session : Single thread
Where
do you use a bridge in real time?
we use in scenarios like publishing message
from Topic to Queue, Store message in EMS for retrieval in case if there is any
problem while moving data from one process to another.
When ever you are decided to use message
selectors on BW, use bridges and use message selector on bridges, which is more
powerful than using message selectors on BW.
Where
is the App Manage located at?
/tra//bin
3 files (batch) are ready for deployment. out
of which only 2 files must be deployed together
and not deploy the other one. How can we do
this using App Manage?
Batch means is it a single ear with multiple
process archives,if-so,don't pass the third process archive in the config
file.
What
are the steps to perform Server Side Load Balancing on the local machine?
1. Make a duplicate copy of the “cfgmgmt” Folder and rename it to “cfgmgmt2”
2. Make sure that the Server Name is same in the “tibemsd.conf” file in both the folders.
3. Change the port number in the second folder’s “tibemsd.conf” file (listen = tcp://xxxx)
4. Start both copies of the servers from the command prompt (ex: C:\ .. \ems\5.1\bin\tibemsd –config
5. “C:\ .. \cfgmgmt\ems\data\tibemsd.conf”)
6. In TIBCO Designer, modify the JMS Connection “Provide URL” to contain both the servers
( ex: tcp://localhost:7222 | tcp://localhost:7223)
2. Make sure that the Server Name is same in the “tibemsd.conf” file in both the folders.
3. Change the port number in the second folder’s “tibemsd.conf” file (listen = tcp://xxxx)
4. Start both copies of the servers from the command prompt (ex: C:\ .. \ems\5.1\bin\tibemsd –config
5. “C:\ .. \cfgmgmt\ems\data\tibemsd.conf”)
6. In TIBCO Designer, modify the JMS Connection “Provide URL” to contain both the servers
( ex: tcp://localhost:7222 | tcp://localhost:7223)
What
are the steps to setup Fault Tolerance servers on the local machine?
1. Make a duplicate copy of the “cfgmgmt”
Folder and rename it to “cfgmgmt2”
2. Make sure that the “Server” Names and
“Listen” ports are not the same in the “tibemsd.conf” file in both the folders.
3. Change the port number in the “tibemsd.conf”
file (i.e ft_active = “listen port of the other server”) in both the
“cfgmgmt” folders.
4. Start both copies of the servers from the
command prompt
(ex: C:\ .. \ems\5.1\bin\tibemsd –config “C:\
.. \cfgmgmt\ems\data\tibemsd.conf”)
What
is the use of Bridges?
Some applications require the same message to
be sent to more than one destination possibly of different types. So we use
bridges
What
is the syntax to create Bridges without Message Selector?
create bridge source=queue:bridgequeue
target=topic:bridgetopic
What
is the syntax to delete a bridge?
delete bridge source=queue:bridgequeue target=topic:bridgetopic
What is the syntax to create Bridges with
Message Selector?
create bridge source=queue:bridgequeue
target=topic:bridge topic selector="keyword"
What is the use of Bridges and Routes?
Both are used to channel messages from senders
to receivers. Bridge act as connector between two different queue and Routes
act as connector between different server for sending message and receiving
acknowledgement of delivery.
What are the steps required to create a Route
between two Servers?
1.Make a duplicate copy of the “cfgmgmt” Folder and rename it to “cfgmgmt2”
2.Make sure that the Server Name is NOT the same in the “tibemsd.conf” file in both the folders.
3.Change the port number in the second folder’s “tibemsd.conf” file (listen = tcp://xxxx)
4.Set the routing property to enabled in the “tibemsd.conf” files in both the folders open factories.conf under
“cfgmgmt2” and change the settings for General Connection Factory, Queue Connection Factory and opicConnectionFactory URL to (tcp://xxxx)
5.Create Route on Server 1 (route “Server2-Name” url=tcp://localhost:xxxx)
6.Create global queue / topics on both servers as required
7.Start both copies of the servers from the command prompt (ex: C:\ .. \ems\5.1\bin\tibemsd –config
“C:\ .. \cfgmgmt\ems\data\tibemsd.conf”)
8.Test the route by using queue / topic in a BW Process
How
to create a transport between RV and EMS?
Transport can be established between RV and EMS topic or queue.
The message can be imported as well as exported from RV.Important point to remember is, with Topic for transport the messages can be imported and exported from RV But in the case of Queues the message can only be imported from RV. Follow these steps to establish transport between RV and EMS
1)For enabling the transport :
In the configuration file tibemsd.conf set the parameter tibrv_transports to enabled. The default value is disabled.
2)To set the type of parameters for transport:
In the transports.conf file set the parameters in Transport definitions (in the configuration file transports.conf) specify the communication protocol between EMS and the external system.
The parameters can be as follows:
[RV01]
type = tibrv
topic_import_dm = TIBEMS_RELIABLE
service = 7200
network =
daemon = tcp:host:7200
topic_import_dm= TIBEMS_NONPERSISTENT
Here
RV01 is the name of the transport.
type = required parameter which can be set to tibrv or rvcm(for certified messages)
service = UDP port.if absnt the default is 7200
network = IP address.
Daemon = TCP Port.
topic_import_dm = delivery mode for importing the messages and the values can be TIBEMS_RELIABLE,
TIBEMS_PERSISTENT OR TIBEMS_NONPERSISTENT
Similarly the parameters can be set for topic_export_dm and queue_import_dm. export_headers = The default
value is true and can be set to false if there is no requirement of exporting the JMS headers.
export_properties = The default value is true and cane be set to false if there is no requirement of exporting the JMS properties.
3)Destination definitions (in the configuration files topics.conf and queues.conf) can set the import and export
Properties to specify one or more transports.
Can set the import/export properties by either making an entry in topics.conf or queues.conf files directly like
topic.sample import="RV" where topic.sample is the name of the topic.
or in the admin tool use :
addprop topic myTopics.news import="RV01,RV02" which will add property import to my Topics in topics.conf files
Key Points:
The transport takes place when the topic name and the RV subject name are same.
For topics:
When a topic specifies import on a connected transport, tibemsd imports messages only when the topic has registered subscribers.
For queues:
When a queue specifies import on a connected transport, tibemsd immediately begins importing messages to the queue, even when no receivers exist for the queue.
The message can be imported as well as exported from RV.Important point to remember is, with Topic for transport the messages can be imported and exported from RV But in the case of Queues the message can only be imported from RV. Follow these steps to establish transport between RV and EMS
1)For enabling the transport :
In the configuration file tibemsd.conf set the parameter tibrv_transports to enabled. The default value is disabled.
2)To set the type of parameters for transport:
In the transports.conf file set the parameters in Transport definitions (in the configuration file transports.conf) specify the communication protocol between EMS and the external system.
The parameters can be as follows:
[RV01]
type = tibrv
topic_import_dm = TIBEMS_RELIABLE
service = 7200
network =
daemon = tcp:host:7200
topic_import_dm= TIBEMS_NONPERSISTENT
Here
RV01 is the name of the transport.
type = required parameter which can be set to tibrv or rvcm(for certified messages)
service = UDP port.if absnt the default is 7200
network = IP address.
Daemon = TCP Port.
topic_import_dm = delivery mode for importing the messages and the values can be TIBEMS_RELIABLE,
TIBEMS_PERSISTENT OR TIBEMS_NONPERSISTENT
Similarly the parameters can be set for topic_export_dm and queue_import_dm. export_headers = The default
value is true and can be set to false if there is no requirement of exporting the JMS headers.
export_properties = The default value is true and cane be set to false if there is no requirement of exporting the JMS properties.
3)Destination definitions (in the configuration files topics.conf and queues.conf) can set the import and export
Properties to specify one or more transports.
Can set the import/export properties by either making an entry in topics.conf or queues.conf files directly like
topic.sample import="RV" where topic.sample is the name of the topic.
or in the admin tool use :
addprop topic myTopics.news import="RV01,RV02" which will add property import to my Topics in topics.conf files
Key Points:
The transport takes place when the topic name and the RV subject name are same.
For topics:
When a topic specifies import on a connected transport, tibemsd imports messages only when the topic has registered subscribers.
For queues:
When a queue specifies import on a connected transport, tibemsd immediately begins importing messages to the queue, even when no receivers exist for the queue.
When
a topic and a queue share the same name, at most one of them may set the import
property.
A distributed message bus with multi-protocol
support for Java Message Service (JMS), TIBCO Rendezvous®, and TIBCO Smart Sockets. TIBCO supports many of the leading open standards, including web
services, and provides adapters for third-party applications and infrastructure
including IBM MQSeries. This makes it possible for companies to reuse their
existing investments and focus on delivering new functionality Built-in
monitoring and management capabilities that provide detailed administrative
functions and statistics and support automation through an administrative API
or command-line shell. Companies can also leverage TIBCO's common monitoring
and management framework for top-down, end-to-end distributed monitoring and
management of TIBCO and non-TIBCO products
Multicast – Features
Features
Facts
Fault-Tolerance setup-A(Which deals with configuration of the files for fault tolerance)
For example, if a topic example.transport and a
queue example.transport are both defined, only one may specify the import
property.
TIBCO EMS Multicast - Features
TIBCO EMS is a distributed and reliable
architecture, with support for load-balancing, routing, and fault tolerant
configurations that together remove single points of failure.
Features
By using TIBCO's messaging solution, companies
have been able to reliably support over 50,000 messages per second and achieve
99.999% uptime.
Multicast – Features
Multicast is a messaging model that allows the
EMS server to send messages to multiple consumers simultaneously by
broadcasting them over an existing network.
Features
Multicast is highly scalable
Multicast reduces the amount of bandwidth
consumed
Multicast reduces the number of operations
performed by the server
Multicast broadcasts the message only once
where as in case of publish and subscriber for each of theconsumer a copy of
the message is getting published
Facts
Multicast does not guarantee message delivery
Messages requiring a high degree of reliability
should not use multicast
Multicast offers last-hop delivery only; it
cannot be used to send messages between servers.
Multicast should not be used in applications
where security is a priority
Fault-Tolerance setup-A(Which deals with configuration of the files for fault tolerance)
Note:The Ems data store should be in SAN or
NAS,in actual Production Environment..so that the datastore is accessible by
both primary and back up server
SAN-Storage Area Network
NAS-Network Area storage
But for our case we would use just operating
system file system (shared by both primary and Backup server)
Fault
Tolerance configuration setup
Parameters will be in Bold and Inclined for
easy identification
Configuring
Primary server
open the c:\tibco\ems\bin\tibemsd.conf (This
file is called Ems configuration file)
Server=EMS-SERVER-RAMU(This value is upto your
choice)
Listen=tcp://7222(This value is upto uour
choice)
Ft_active=tcp://7444(This value is upto your choice)
Configuring
Backup server
Create a folder called Backup in that please
copy all the *.conf files(only configuration files) from c:\tibco\ems\bin\ and
place it in c:\tibco\ems\bin\Backup\
Note:From now we will work in the Backup
Folder, open tibemsd.conf file in the folder
Server=EMS-SERVER-RAMU(This value must match
the value of the server parameter in primary server's tibemsd.conf file)
Listen=tcp://7444(This value must match the
value in Ft_active paramter in primary server's tibemsd.conf file)
Ft_active=tcp://7222(This value must match the
value in Listen parameter in primary server's tibemsd.conf file)
store=c:\tibco\ems\bin\datastore(This value
must match the value in store parameter in primary server's tibemsd.conf
file,note that the value in primary server's tibemsd.conf file is just
datastore)
Prepends this path to c:\tibco\ems\bin\Backup\
below list in the backup sever tibemsd.conf
users=c:\tibco\ems\bin\Backup\users.conf
groups=c:\tibco\ems\bin\Backup\groups.conf
topics=c:\tibco\ems\bin\Backup\topics.conf
queues=c:\tibco\ems\bin\Backup\queues.conf
acl_list=c:\tibco\ems\bin\Backup\acl.conf
factories=c:\tibco\ems\bin\Backup\factories.conf
routes=c:\tibco\ems\bin\Backup\routes.conf
bridges=c:\tibco\ems\bin\Backup\bridges.conf
transports=c:\tibco\ems\bin\Backup\transports.conf
tibrvcm=c:\tibco\ems\bin\Backup\queues.conf
durables=c:\tibco\ems\bin\Backup\durables.conf
If you observe the tibemsd.conf file in primary
server and compare the tibemsd.conf file in Backup server
The values for some parameters in primary
tibemsd.conf file is just for example "users=users.conf" where as in backup server tibemsd. conffile .
we give "users=c:\tibco\ems\bin\Backup\users.conf".The reason why because
while installing the Ems server ,it sets these values and it knows where to
look for the path , so thats the reason why the full path is not mentioned for
various parameters in tibemsd.conf for primary server
Fault-Tolerance
Setup-B(which deals with starting primary and back up server--which will be in
standby mode)
This post is continuation of Fault Tolerance
Setup-A
Go to All programs>Run>type cmd
You will get a command prompt window
Type command: cd c:\tibco\ems\bin
Now you will be inside bin directory
Start Primary Server
Type command: tibemsd (This is a application )
Start Backup Server
Open another command prompt
Navigate to the directory by entering the below
command
cd c:\tibco\ems\bin
Give the following command
tibemsd -config Backup\tibemsd.conf (This is
not done in primary but you are doing in back up server , since Primary server
tibemsd.conf file is in same directory as tibemsd application)
In the backup sever command prompt you can see
that it is in standby mode for primary (tcp://7222)
M Messaging
|
|
What are the
Messaging Tools Provided by TIBCO?
· EMS
· Rendezvous
|
|
What is the
difference between EMS & RVD?
EMS
· Uses TCP
· Functions within the IP Layer
· Can be used within the Intranet and the Internet
· Slower than RVD
RVD
· Uses UDP
· Functions within the Network Layer
· Considerably Faster than EMS
· Can be used only within the Intranet (LAN)
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|
What are the
Messaging Modes?
· P2P (Queue)
· Pub / Sub (Topic)
|
|
What are the two
types of Delivery Modes in Messaging?
· Synchronized
· Asynchronized
|
|
What are the
Services provided by Messaging?
· Reliable (At Least Once)
· Guaranteed (At Most Once)
· Transactional (Only Once)
|
|
What are files used
by TIBCO to maintain the Connection details?
Meta.db (Connection
Details)
Async.db (Fire &
Forget Messages)
Sync.db (Acknowledge
Back Messages)
|
|
What are the
configuration files used by TIBCO EMS?
Tibemsd.conf
Queue.conf
Topic.conf
|
|
What is the maximum
size and maximum number of message possible using TIBCO EMS?
Maximum Message Size
= 512MB [ Both Topic & Queue ]
Maximum No. Of
Messages = 3600 messages / second
|
|
What is the Maximum
Retransmission Time?
Maximum
Retransmission Time = 60 seconds
|
|
What are the
delivery modes supported by EMS server?
· Persistent
· Non-persistent
· Reliable
|
|
What are the message
types supported by EMS?
· Text
· XML
· Bytes
· Stream
· Simple
· Object
· ObjectRef
· Map
|
|
What are the
different types of Queues?
· Static Queue
· Dynamic Queue
· Temp Queue
· System Queue
|
|
What are the
permissions that you can grant to users to access queues?
· Receive
· Send
· Browse
|
|
How
do you remove individual messages from destinations?
Using purge command, you can delete messages
from queues and topics.
What
is the use of “Durable” option?
Durable option enables persistence for EMS
messages by creating Local Inboxes at the receiver end. The Message will exist
as a reference till it is consumed by the corresponding receivers.
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
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.
What
is the difference between Queues and Topics?
Queue
· Guaranteed Service
· Only the Target gets the message (One message
per Consumer)
· Uses Peer-to-Peer Mode to deliver messages
· Blocking
· Load Balancing is possible
Topic
· Reliable Service
· Everyone active gets the message (One message
may Consumers)
· Uses Pub / Sub mode to deliver messages
· Non-Blocking
· Load Balancing is not Possible
What
is the use of secured queues and topics?
Setting ‘secure’ property to queues/topics can
restrict unauthorized users from publishing/sending and subscribing/receiving
the messages.
What
is Load Balancing?
Load Balancing is a technique to distribute
workload evenly across two or more machines or resources, in order to get
optimal resource utilization, maximize throughput, minimize response time, and
avoid overload. Using multiple Receivers with load balancing, instead of a
single Receiver, may increase reliability through redundancy.
How
is Load Balancing implemented on both Queue & Topic?
Topic : Load Balancing is only possible on
Queues
Queue : Load Balancing is implemented on the
receivers end. Since Load Balancing not possible on the sender side.
What
is “Certified Messaging”?
Rendezvous (RV) uses 'UDP'. Therefore each
message is sent as a packet with a sequence number and a subject attached. So,
RV is also called as "Subject Based Messaging". Rendezvous Daemon
(RVD) converts the message into packets and publish to the network. At the
receiver end, RVD again converts the packets to the message and sends it to the
receiver. This message is stored only for 60 seconds in the RVD before the
message is lost. To avoid this, RV introduced a concept called
'Certified Messaging(CM)'. RVCM uses Ledger to save
the messages. The sender stores all outbound messages of the registered
receivers which have an agreement in the ledger unless the sender receives an
acknowledgement from the receiver.
What is the difference between RVD and RVRD?
RVD is Used for local subnet communication.
RVRD is Used for Remote communication.
What are the steps to perform Server Side Load
Balancing on the local machine?
1. Make a duplicate copy of the “cfgmgmt”
Folder and rename it to “cfgmgmt2”
2. Make sure that the Server Name is same in
the “tibemsd.conf” file in both the folders.
3. Change the port number in the second
folder’s “tibemsd.conf” file (listen = tcp://xxxx)
4. Start both copies of the servers from the
command prompt (ex: C:\ .. \ems\5.1\bin\tibemsd –config “C:\ .. \cfgmgmt\ems\data\tibemsd.conf”)
5. In TIBCO Designer, modify the JMS Connection
“Provide URL” to contain both the servers ( ex: tcp://localhost:7222 |
tcp://localhost:7223)
What is Fault Tolerance?
Fault Tolerance is the ability of a system to
respond gracefully to an unexpected hardware or software failure. Fault
Tolerant systems mirror all operations, i.e. every operation is performed on
two or more duplicate systems, so if one fails the other can take over.
What are the steps to setup Fault Tolerance
servers on the local machine?
1. Make a duplicate copy of the “cfgmgmt”
Folder and rename it to “cfgmgmt2”
2. Make sure that the “Server” Names and
“Listen” ports are not the same in the “tibemsd.conf” file in both the folders.
3. Change the port number in the “tibemsd.conf”
file (i.e ft_active = “listen port of the other server”) in both the “cfgmgmt”
folders.
4. Start both copies of the servers from the
command prompt (ex: C:\ .. \ems\5.1\bin\tibemsd –config “C:\ ..
\cfgmgmt\ems\data\tibemsd.conf”)
What is the use of Bridges?
Some applications require the same message to
be sent to more than one destination possibly of different types. So we use
bridges.
What is the syntax to create Bridges without Message
Selector?
create bridge source=queue:bridgequeue
target=topic:bridgetopic
What is the syntax to delete a bridge?
delete bridge source=queue:bridgequeue
target=topic:bridgetopic
What is the syntax to create Bridges with
Message Selector?
create bridge source=queue:bridgequeue
target=topic:bridge topic selector="keyword"
What is the use of Bridges and Routes?
Both are used to channel messages from senders
to receivers. Bridge act as connector between two different queue and Routes
act as connector between different server for sending message and receiving
acknowledgement of delivery.
What are the steps required to create a Route
between two Servers?
1. Make a duplicate copy of the “cfgmgmt”
Folder and rename it to “cfgmgmt2”
2. Make sure that the Server Name is NOT the
same in the “tibemsd.conf” file in both the folders.
3. Change the port number in the second
folder’s “tibemsd.conf” file (listen = tcp://xxxx)
4. Set the routing property to enabled in the
“tibemsd.conf” files in both the folders
5. open factories.conf under “cfgmgmt2” and
change the settings for GeneralConnectionFactory, QueueConnectionFactory and
TopicConnectionFactory URL to (tcp://xxxx)
6. Create Route on Server 1 (route
“Server2-Name” url=tcp://localhost:xxxx)
7. Create global queue / topics on both servers
as required
8. Start both copies of the servers from the
command prompt (ex: C:\ .. \ems\5.1\bin\tibemsd –config “C:\ ..
\cfgmgmt\ems\data\tibemsd.conf”)
9. Test the route by using queue / topic in a
BW Process
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