In WebSphere MQ or WMQ, Queue Manager use channel to trmit messages to other QueueManager. Channel carries one way traffic in MQ Series (i.e. channels are uni directional). You can have either sending channel or receiving channel in MQ.
In WebSphere MQ, local queues are queue on same QueueManager while remote queue refers to queue on different QueueManager.
MQ stands for MESSAGE QUEUEING. WebSphere MQ allows application programs to use message queuing to participate in message-driven processing. Application programs can communicate across different platforms by using the appropriate message queuing software products.
Dead letter Queue in WebSphere MQ is a queue which is used by QueueManager to archive messages for a non existent queue. For example of QueueManagerQMGR, receives a messages for queue ABC and if it didn’t exist on that QueueMangaer then message will be routed to dead letter queue.
With message queuing, the exchange of messages between the sending and receiving programs is independent of time. This me that the sending and receiving application programs are decoupled; the sender can continue processing without having to wait for the receiver to acknowledge receipt of the message. The target application does not even have to be running when the message is sent. It can retrieve the message after it is has been started.
QueueManageris primary component of WebSphere MQ or WMQ. QueueManager is responsible for storing and routing messages to other Queue Manager within MQ and it also communicate with outside world e.g. Java program or any other MQ client.
CCDT file or Client Channel Definition table is a binary file which contains connection details required by MQ clients e.g. Java application using JMS to connect to MQ Server. In order to connect to MQ Server, MQ clients needs MQ Server host name, MQ Server port name and server channel name. All these details are encapsulated in CCDT file named as AMQCLCHL.TAB. In order to create MQ Connection, MQ clients needs location of this file, which is provided as configuration. most of MQ errors comes either with incorrect CCDT files.
A middle ware from IBM
Significance of Websphere MQ Series:
The default maximum message length is 4 MB, although you can increase this to a maximum length of 100 MB (where 1 MB equals 1 048 576 bytes).
Persistent messages are usually logged. Logging messages reduces the performance of your application, so use persistent messages for essential data only. If the data in a message can be discarded if the queue manager stops or fails, use a nonpersistent message.
WebSphere MQ messages: Messages are made up of Two parts: Message descriptor, Application data
WebSphere MQ for AIX, V5.3 runs on any machine that supports the AIX V4.3.3 PowerPC® 32.bit, or AIX® V5.1 Power 32 bit only operating system.
Disk Storage: Typical storage requirements are as follows:
Software Requirements: Operating system: The operating systems supported by WebSphere MQ for AIX, V5.3 are:
Databases: DB2 7.1, 7.2
Oracle 8i and 9i
Sybase v12 or v 12.5
A Web Sphere MQ server is a queue manager that provides queuing services to one or more clients. All the Web Sphere MQ objects, for example queues, exist only on the queue manager machine (the Web Sphere MQ server machine), and not on the client. A Web Sphere MQ server can also support local Web Sphere MQ Applications
On Windows systems, use the Web Sphere MQ Services snap-in to display the properties of the queue manager, and check the Make queue manager the default box. You need to stop and restart the queue manager for the change to take effect.
Because the MQ is independent of the Operating System you use i.e. it may be Windows, Solaris,AIX.It is independent of the protocol (i.e. TCP/IP, LU6.2, SNA, NetBIOS, UDP).It is not required that both the sender and receiver should be running on the same platform
These commands are issued from a programme for local or remote administration done by programmers.
If MQ clients sits on same physical server where QueueManager is located than it can create binding connection which is relatively faster than client connection, which is usually created by MQ clients residing on same network but not same host. Most of application uses MQ client connection to connect QueueMangaer, which is easy and flexible.
In Web Sphere MQ, messages can be either persistent or non persistent. Persistent messages are logged and can be recovered in the event of a WebSphere MQ failure. Thus, persistent messages are guaranteed to be delivered once and only once. Nonpersistent messages are not logged. Web Sphere still guarantees to deliver them not more than once, but it does not promise to deliver them once.
MQSC Commands: These commands are used to handle the admin related functions for the components that are present in the MQ Series. In general MQSC commands are used for creating and maintaining Message channels, Queue Managers, Clusters etc…
Control Commands: These commands are used to manage the processes and services that are helpful in the functioning of the MQ Series. In general these commands are used for Channel listener, Channel Initiator, Trigger monitor etc…
Windows systems: If you use Web Sphere MQ for Windows NT and Windows 2000, configuration information is stored in the Windows Registry.
When you install the product, the Web Sphere MQ configuration file (mqs.ini) is created. It contains a list of queue managers that is updated each time you create or delete a queue manager. There is one mqs.ini file per node.
When you create a new queue manager, a new queue manager configuration file (qm.ini) is automatically created. This contains configuration parameters for the queue manager.
if you connected MQ via SSL. SSLPEER is a String usually DN (Distinguished name) of MQ Client which connect to QueueManager securely using QueueManager. This is a mechanism WMQ uses to identify client. In case of Java or JMS client, SSLPEER is DN of client certificate stored in its keyStore and sent to server during SSL handshake.
A Web Sphere MQ client is a component that allows an application running on a system to issue MQI calls to a queue manager running on another system. The output from the call is sent back to the client, which passes it back to the application.
runmqsc QM1 Display qmgr
When messages arrive on a queue, they can automatically start an application using triggering. If necessary, the applications can be stopped when the message (or messages) have been processed.
A message is a string of bytes that is meaningful to the applications that use it. Messages are used to trfer information from one application program to another (or between different parts of the same application). The applications can be running on the same platform, or on different platforms.
WebSphere MQ messages have two parts:
Each command of MQSC starts with a primary parameter, followed by a secondary parameter
As we have seen that dead letter queue is used to store messages which is receives for non existent queue. On the other hand backout queue are application specific queue.If MQ client is not able to process message and ask for redelivery, message is redelivered to client with incremented delivery count. Once this deliveryCountcrossed a configured threshold message is moved to back-out queue for later processing or error handling. In short if MQ Series not able to deliver message to client after a preconfigured attempt, WMQ moves message to backout queue.
MQ v 5.3 supports Windows 2000, Windows 2000XP,Windows 2000NT,
Windows 2003 SE, Windows 2003EE.
Typical storage requirements are as follows:
Connectivity The network protocols supported by WebSphere MQ for AIX, V5.3 are:
Databases: DB2 7.1, 7.2
Oracle 8i and 9i
Sybase v12 or v 12.5
For commands that have too many parameters to fit on one line, use continuation characters to indicate that a command is continued on the following line:
MQSC commands, including their attributes, can be written in uppercase or lowercase. Object names in MQSC commands are folded to uppercase (that is, QUEUE and queue are not differentiated), unless the names are enclosed within single quotation marks. If quotation marks are not used, the object is processed with a name in uppercase.
SCRIPT COMMANDS : After entering in to queue manager we can find script commands. Script commands are same for every queue manager.(These Commands should be used in CAPITAL LETTERS)