c c p ñ MQ stands for ñ WebSphere MQ allows application programs to use to participate in message-driven processing. Application programs can communicate across different platforms by using the appropriate message queuing software products.p c p ñ When messages arrive on a queue, they can automatically start an application using . If necessary, the applications can be stopped when the message (or messages) have been processed.p c p ñÔ.Integration.p 2. Asynchronyp 3. Assured Deliveryp 4. Scalability.p G p ñ. 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 platformp c ñ p ñWith message queuing, the exchange of messages between the sending and receiving programs is independent of time. This means 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.p c ñ p ñ WebSphere MQ for AIX, V5.3 runs on any machine that supports the AIX V4.3.3 PowerPC® 32.bit, or AIX® V5.Ô Power 32 bit only operating system.p · Typical storage requirements are as follows·p Ô Server installation· 50 MBp 2. Client installation· Ô5 MBp 3 Data storage (server)· 50 MBp
4. Data storage (client)· 5 MB.p ! "p # · The operating systems supported by WebSphere MQ for AIX, V5.3 are·p Ô. AIX V4.3.3, with PTF U472Ô77, running in a 32 bit environment, on 32 or 64 bit hardware.p 2. AIX V5.Ô, with PTFs U476879, U477366, U477367 and U477368, and APAR fix IY29345 running 32 bit kernel running on 32 or 64 bit hardware.p 3. AIX V5.Ô, with PTF U476879, U477366, U477367 and U477368, and APAR fix IY29345 running 64 bit kernel running on 64 bit hardware.p º The network protocols supported by WebSphere MQ for AIX, V5.3 are·p Ô. TCP/IPp 2. SNA LU 6.2.p $ " %&'%p # ( )p $ & &*p +" If you want to use the Java Messaging Support, you need the Java Runtime Environment Version Ô.3 or laterp c c p ñ"*, c 'c -'c .'p c ,'c ,p · Typical storage requirements are as follows·p Ô Server installation· 50 MBp 2. Client installation· Ô5 MBp 3 Data storage (server)· 50 MBp 4. Data storage (client)· 5 MB.p º The network protocols supported by WebSphere MQ for AIX, V5.3 are·p Ô. TCP/IPp
2. SNA LU 6.2.p 3. LU 6.2p 4. NetBIOSp $ " %&'%p # ( )p $ & &*p +" If you want to use the Java Messaging Support, you need the Java Runtime Environment Version Ô.3 or laterp
p ñ" A is a string of bytes that is meaningful to the applications that use it. Messages are used to transfer 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.p WebSphere MQ messages have two parts·p Ô. £ The content and structure of the application data is defined by the application programs that use it.p 2. ñ
The message descriptor identifies the message and contains additional control information, such as the type of message and the priority assigned to the message by the sending application. WebSphere MQ defines the format of the message descriptor. For a complete description of the message descriptor,p c /0 1p ñ" The default maximum message length is 0 , although you can increase this to a maximum length of & (where Ô MB equals Ô 048 576 bytes).p c $ - - p ñ" 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.p c - p
ñ" 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.p c $ "p Messages are made up of Two parts· Message descriptor, Application datap Types of messages?p A Message sent with no response expected.p å A Message sent for which a response is expected.p å A Response Message for a requested message.p å
A Message that describes the occurrence or event
p
Ex COA/CODp Sizes ?p QmanageràÔ0000 Msgs Maxmsglengthà4 Mbp Queueà5000 Msgs Maxmsglengthà4 Mbp c $ p ñ"MaxMsgLengthp c º p ñ" A Web Sphere MQ î 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.p c p ñ" A Web Sphere MQ 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 MQp Applicationsp c #$2 c $ p ñ"Ô. Queue Manager 2. Queuesp
3. Channels 4. Processes 5. Name listsp º $2 p ñ"For MQ Channels it is 20 Charactersp For Remaining objects it is 48 characters.p c $ $ p ñ· Ô4Ô4p Difference between MQSC commands and Control commands?p 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«p 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«p º$ º p ñ" 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.p º!-.º#ñ·-p After entering in to queue manager we can find script commands.p Script commands are same for every queue manager.p (These Commands should be used in CAPITAL LETTERS)p · DEFINE ·-To define/create MQ manager objects like queue,
p
Channels, process, and listener.p · ALTER ·-to update or modify the existing objectsp · DISPLAY ·-to view all the properties of a particular object or top Display all objectsp · DELETE ·-to delete created objectsp
· CLEAR ·-to clear the message from the queuep · END ·-to come out of the queue managerp · PING ·-to check whether other side channel / queue manager is ready to accept our request.p · START ·- to start the particular channel or listenerp · STOP ·-to stop particular channel or listenerp · REFRESH ·-used to refresh the security every time after giving or executing, set mgr or command for queue manager or objectp · RESET ·-used to reset channel,cluster,queue managerp · RESOLVE ·-to resolve the channel which is in indoubt statep · SUSPEND ·-to suspend a queue manager from a cluster environmentp · RESUME ·-to remove a queue manager from a cluster environmentp G º 1p ñ" 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·p Ô. A minus sign ( ) indicates that the command is to be continued from the start of _ the following line.p 2. A plus sign (+) indicates that the command is to be continued from the first nonblank character on the following line.p What is programmable command format (PCF) commands?p These commands are issued from a programme for local or remote administration done by programmers.p c º p ñ· crtmqma a MY.DEFAULT.XMIT.QUEUE a DEAD.LETTER.QUEUE QMÔp Here a used to define the Queue manager QMÔ as a Default Queue manager
p
a is used to define the default transmission Queue a is used to define the default dead letter queue.p G / p
ñ" 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.p c $ p ñ" c · If you use Web Sphere MQ for Windows NT and Windows 2000, configuration information is stored in the Windows Registry.p · Ô. 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.p 2. 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.p c p ñ" p c p ñ" a p The command waits until all applications have stopped and the queue manager has ended.p 3 p This type of shutdown does not wait for applications to disconnect from the queue manager.p c 4 p AMQ4044 Queue manager stoppingp c p ñ" p $ & p ñ"runmqsc QMÔ Display qmgrp c p ñ" A is a data structure used to store messages. A queue manager owns each queue. The queue manager is responsible for maintaining the queues it owns, and for storing all the messages it receives onto the appropriate queuesp c / p
ñ5000p Types of Queues?p Local Queue Remote Queues Alias Queues
p
Model Queue Dynamic Queues Cluster Queues.p " A safe place to store messages for Prior-To-Delivery, it belongs to the Qmgr to which the application is connected.p " Model queue is a template of a queue definition that uses when creating a dynamic queue.p ñ " Queue definition, which is Alias to an actual Local or Remote Q. Used for security and easy maintenance. p ! " Object that defines a Queue belongs to another Q Manager (Logical Def).p " An initiation queue is a local queue to which the queue manager writes a trigger message when certain conditions are met on another local queuep " Such a queue is defined ³on the fly´ when the application needs it. Dynamic queues may be retained by the queue manager or automatically deleted when the application program ends. Use- To store intermediate results.p º " Custer queue is a local queue that is known throughout a cluster of queue managers.p ! a. a " A request message must contain the name of the queue into which the responding program must put the Reply Message.p " Provides Messaging services and manages the Queues, Channels, and Processes that belongs to it.p ñ " Queue-manager aliases, are created using a remote-queue definition with a blank RNAME.p c $ ! p ñ"Ô.Name of the Queue 2. Transmission Queue Name.p 3. Remote QueueManager name 4. Remote Local Queue Namep G p ñ"Queues are defined to Web Sphere MQ using·p Ô. The MQSC command DEFINEp
2. The PCF Create Queue commandp c . p ñ"Transmission queues are queues that temporarily store messages that are destined for a remote queue manager. You must define at least one transmission queue for each remote queue manager to which the local queue manager is to send messages directly.p c p ñ" Initiation queues are queues that are used in triggering. A queue manager puts a trigger message on an initiation queue when a trigger event occurs. A trigger event is a logical combination of conditions that is detected by a queue manager.p c 0 p ñ" A dead-letter (undelivered-message) queue is a queue that stores messages that cannot be routed to their correct destinations. This occurs when, for example, the destination queue is full. The supplied dead-letter queue is called 5.ñ0..! For distributed queuing, define a dead-letter queue on each queue manager involved.p c /6 *, p ñThey support around
of Sizep
G . p ñChange the usage attribute from normal to Transmissionp 0 0 ºº &p ñ"runmqsc QMÔp Define qlocal (LQ)p c 1c- 7 p ñ"Queues can be characterized by the way they are created·p Ô. - are created by an administrator using the appropriate MQSC or PCF commands. Predefined queues are permanent; they exist independently of the applications that use them and survive Web Sphere MQ restarts.p 2 are created when an application issues an MQOPEN request specifying the name of a . The queue created is based on a , which is called a model queue.p c ñ p
ñ"Ô.First-in-first-out (FIFO).p 2.Message priority, as defined in the message descriptor. Messages that have the same priority are retrieved on a FIFO basis.p 3. A program request for a specific message.p c - $ p ñ" A î object defines an application that starts in response to a trigger event on a WebSphere MQ queue manager. The process definition attributes include the , the , and specific to the application.p What is intercommunication and its components to send message ?p c p ñ" In Web Sphere MQ, intercommunication means sending messages from one Queue manager to another. The receiving queue manager could be on the same machine or another; nearby or on the other side of the world. It could be running on the same platform as the local queue manager, or could be on any of the platforms supported by Web Sphere MQ. This is called a $ .p Message channels Message channel agents
p
Transmission queues Channel initiators and listeners
p
Channel-exit programsp c $ 89p Web Sphere MQ handles communication in a distributed environment such as this using DQM.The local queue manager is sometimes called the and the remote queue manager is sometimes called the or the partner queue manager.p c #$2 p ñ"# "p &Transmission Queue 2. Remote queue definition.p 3. Dead Letter Queue(recommended) 4. Sender Channelp #. p Ô. Local Queue 2. Dead Letter Queue 3. Receiver Channel 4.Listenrp ***.The sender and receiver channels names should be same.p
c p ñ" º are objects that provide a communication path from one queue manager to another. Channels are used in distributed queuing to move messages from one queue manager to another. They shield applications from the underlying communications protocols. The queue managers might exist on the same, or different, platforms. Different types of Channels·p Ô. Sender-Receiver Channelsp 2. Requester-Server Channelsp 3. Client Connection channelsp 4. Server Connection Channels.p 5. Cluster Sender.
p
6. Cluster Receiver Channelsp What are MQI channels and there types?
p
MQI channels are the channels that carry messages from MQ Client application to the MQ server and vice versa.They are Bi-directional Channels p Ô. Server-connection 2. Client-connectionp How many Channel Combinations?p Ô.Sender-receiver Channel 4.Requester-server Channelp 2.Requester-sender Channel 5. Server-receiver Channelp 3.Cluster-Sender- Receiver Channel 6.Client-Server Channelp c $ º p ñ"Ô. The Name of the Channel 4.Transport Type 2. The Connection name 5.Scyexitp c º p ñ"º "p & ,! p !0 p c $ 67 p
p
ñ" Before running state first the channel will initializes the listener & Binds with the Receiver Channel then it goes into running mode.p . º ñ$ p Batch Heartbeat Interval (BATCHHB)· This heartbeat interval allows a sending channel to verify that the receiving channel is still active just before committing a batch of messages. If the receiving channel is not active, the batch can be backed out rather than becoming in-doubt, Batch interval (BATCHINT), Batch size (BATCHSZ), Channel type (CHLTYPE), Cluster (CLUSTER), Cluster namelist (CLUSNL), Connection name (CONNAME), Convert message (CONVERT), Disconnect interval (DISCINT), Heartbeat interval (HBINT), KeepAlive Interval (KAINT), Long retry count (LONGRTY), Long retry interval (LONGTMR), Maximum message length (MAXMSGL)p Why is Channel RETRYINT attribute used?
p
If a message is places in DLQ because of put inhibited or queue full condition, the DLQ handler attempts to put the message back to the destination queue. This interval is called as RETRYINT by default the retry interval is 60 seconds.p Receiver Cluster Receiver Requester
p
What is channel disconnect interval?p This is a time-out attribute, specified in seconds, for the server, cluster-sender, and cluster-receiver channels. The interval is measured from the point at which a batch ends, that is when the batch size is reached or when the batch interval expires and the transmission queue becomes empty. If no messages arrive on the transmission queue during the specified time interval, the channel closes downp Explain the channel attribute BATCHSIZE?p BATCHSIZE denotes the maximum number of messages that can be sent through a channel before taking a checkpoint. This parameter is valid only for channels with a channel type (CHLTYPE) of SDR, SVR, RCVR, RQSTR, CLUSSDR, or CLUSRCVR. The value must be in the range Ô through 9999.p c ñ.ºGGñ!. ñ..!:ñ0 p ñ" The batch heartbeat interval allows a sending channel to verify that the receiving channel is still active just before committing a batch of messages, so that if the receiving channel is not active, the batch can be backed out rather than becoming in-doubt, as would otherwise be the case. By backing out the batch, thep messages remain available for processing so they could, for example, be redirected to another channel.p c ; ñ p ñ" The Keep Alive Interval parameter is used to specify a time-out value for a channel. The Keep Alive Interval parameter is a value passed to the communications stack specifying the Keep Alive timing for the channel. It allows you to specify a different keep alive value for each channel. The value indicates a time, in seconds, and must be in the range 0 to 99999.p
c 0# ! p ñ" Specify the maximum number of times that the channel is to try allocating a session to its partner. If the initial allocation attempt fails, the î number is decremented and the channel retries the remaining number of times.p What are the ways to start a channel?p Use the MQSC command START CHANNELp Use the control command runmqchl to start the channel as a processp Use the channel initiator to trigger the channelp Type of channel states·p Inactive and Current- Stopped, Starting, Retrying and Activep What are the three options for stopping channels?
p
QUIESCE FORCE TERMINATEp What are the components of message channel?p A queue manager to communicate with another queue manager uses message channel. The components of a message channel arep & Sender Message channel agent· Sender MCA is a program that transfers messages from a transmission queue to a communication linkp Receiver MCA· It transfers messages from the communication link into the target queuep , Communication unidirectional.p
protocol·
Responsible
for
transferring
messages
A
message
channel
is
c º 8ºñ9 p ñ" A message channel agent (MCA) is a program that controls the sending and receiving of messages. There is one message channel agent at each end of a channel. One MCA takes messages from the transmission queue and puts them on the communication link. The other MCA receives messages and delivers them onto a queue on the remote queue manager.p A message channel agent is called a ºñif it initiated the communication; otherwise it is called a ºñ.p c º 0 p ñ" A
acts as a for sender channels, because a transmission queue may be defined as a triggered queue. When a message arrives on a transmission queue that
satisfies the triggering criteria for that queue, a message is sent to the initiation queue, triggering the channel initiator to start the p appropriate sender channel. You can also start server channels in this way if you specified the connection name of the partner in the channel definition. This means that channels can be started automatically, based upon messages arriving on the appropriate transmission queue. p You need a program to start receiving (responder) MCAs. Responder MCAs are started in response to a startup request from the caller MCA; the channel listener detects incoming network requests and starts the associated channel.p º p Due to· Ô. Xmitq is set to get disabled 2. Network Issuesp 3.QueueManager Stopped 4. Listener is not running 5.TriggerTurned Offp Explain Channel-Exit programs and what are the types?
p
Channel-exit programs are called at defined places in the processing carried out by MCA programsp Security Exit· You can use security exit programs to verify that the partner at the other end of a channel is genuinep Message Exit· Message Exit can be used for Encryption on the link, message data conversion, validation of user ID, p Message-retry Exit· Message-retry exit is called when an attempt to open the target queue is unsuccessfulp Sender and receiver Exit· You can use the send and receive exits to perform tasks such as data compression and decompressionp Channel auto-definition ExitTransport-retry Exitp c 0 $ p ñ"There are two different types availablep Ô. º · The circular logging is used for restart recovery. It is the default logging method. Circular is used in Development and Testing Queues. Circular logging keeps all restart Data in a ring of log files. Logging fills the first file in the ring, then moves on to the and so on, until all the files are full. It then goes back to the first file in the ring and starts This continues as long as the product is in use, and has the advantage that you never run out of log files.p 2. 0 · Linear logging gives you both restart recovery and media recovery. It is used in Production. Linear logging keeps the log data in a continuous Sequence of files. Space is not reused, so you can always retrieve any record logged from the time that the queue manager was created. As disk space is
finite, you might have to think about some form of archiving. It is an administrative task to manage your disk space for the log, reusing Or extending the existing space as necessary.p c 6 p ñ" "p c · C· Program Files IBM WebSphere MQ log qmgrp "/var/mqm/log
p
c 6 p ñ" In Web Sphere MQ for Windows NT and Win 2000, the minimum value is 32, and the maximum is Ô6 384. The default value is 256, giving a default log size of Ô MB.p In Web Sphere MQ for UNIX systems, the minimum value is 64, and the maximum is Ô6 384. The default value is Ô024, giving a default log size of 4 MB.p G 6 p ñ< You cannot change the log file size. For this you need to drop and re-create the queue manager. The number of log files primary & secondary can be changed but you need to restart the Q manager for the changes to take effect.p
$ p ñ"- " The number of primary log files to be allocated is ,by default the minimum is and MAX in Win *, / Unix *&p " The number of secondary log files to be allocated is by default the minimum is & and MAX in Win * / Unix *)p c p ñ"crtmqlsr -t tcp -m QMNAME -p portnop c *,: p ñ"runmqlsr -t tcp -m QMNAME -p portnop c p ñ"amqmdainp c º p ñ"Ô. · to start the command serverp
2. · to display the command serverp 3. · To end the command server.p p ñ" If the target queuemanager doesn.t contain the dead letter queue defined and if the messages are running on a fast channel and of non persistant,Then there is a chance of the message loss.p c 6 p ñ· -m QMName -t queue -n Queuename -p GUEST +allp c / p ñ" *("!º !ñ!!#!p *)"!º !#.ñ:ñ0ñ 0p ,,"!º# ñ:ñ0ñ 0p (*"!º;#c# +º.ñp )"!ºº#º.# !#;p 0,"!º# +º..5-!!#!p (="!º;#c# +º. !p ,*"!º#.ñ.G#!>p c p ñ"& "In binding mode, also known as server connection, the communication to the queue manager utilizes inter-process communications. One of the key factors that should be kept in mind is that binding mode is available only to programs running on the MQSeries server that hosts the queue manager. A program using binding mode will not run from an MQSeries client machine. Binding mode is a fast and efficient way to interact with MQSeries. Certain Facilities, such as XA transaction co-ordination by queue manager, are available only in binding mode.p º º " Client connection uses a TCP/IP connection to the MQSeries and enables communications with the queue manager. Programs using client connections can run on an MQSeries client machine as well as on an MQSeries server machine. Client connections use client channels on the queue manager to communicate with the queue manager. The client connection does not support XA transaction coordination by the queue manager.p c $+ p ñ"JMS applications use either the point-to-point (PTP) or publish/subscribe style of messaging.p
- a a- · Point-to-point messaging involves working with queues of messages. The sender sends messages to a specific queue to be consumed normally by a single receiver. In point-to-point communication, a message has at most one recipient. A sending client addresses the message to the queue that holds the messages for the intended (receiving) client.p -$ 1$$ " In contrast to the point-to-point model of communication, the publish/subscribe model enables the delivery of a message to multiple recipients. A sending client addresses, or publishes, the message to a topic to which multiple clients can be subscribed. There can be multiple publishers, as well as subscribers, to a topic.p - $ p ñ" It is possible to define more than one channel per transmission queue, but only one of these channels can be active at any one time. This is recommended for the provision of alternative routes between queue managers for traffic balancing and link failure corrective action. A transmission queue cannot be used by another channel if the previous channel to use it terminated leaving a batch of messages in-doubt at the sending end.p c p ñ" QMNamep Ñ channel (channel name).p c -$ $$ p ñ"The $ command is used to start a broker. The first time this command is run on a queue manager, all the relevant MQSeries objects are automatically created.p 3 $
-m MYQMGRNAMEp
The $ command is used to check the status of the broker. Possible states are· starting, running, stopping, quiescing, not active and ended abnormally.p 3 $
-m MYQMGRNAMEp
The $ command is used to stop a broker. There are two options· a requests a controlled shutdown (default), arequests an immediate shutdown.p a $
-i -m MYQMGRNAMEp
c p ñ" If there is no direct communication link between the source queue manager and the target queue manager, it is possible to pass through one or more intermediate queue managers on the way to the target queue manager. This is known as a multi-hop.p
What is Local administration and Remote administration?p 0 ñ " Means carrying out administration tasks on any queue managers you have defined on your local system.p ! ñ " This allows you to issue commands from your local system that are processed on another system. For example, you can issue a remote command to change a queue definition on a remote queue manager. You do not have to log on to that system, although you do need to have the appropriate channels defined. The queue manager and command server on the target system must be runningp Difference between Control Commands used in Windows and other Os?p Control commands on are case sensitive other OS but Windows they can be used any way.p What is MQOO_BIND_ON_OPEN option on the MQOPEN call ?p When this attribute is set it forces all the messages sent to this queue to be sent to the same instance of the queue (go to the same queue in cluster)p Difference between MQPUT and MQPUTÔ call ?p The MQPUTÔ call always operates as though MQOO_BIND_NOT_FIXED were in effect, that is, it always invokes the workload management routine.p When is Channel security exit program called?p Are called at MCA initiation and terminationp Stopping unauthorized queue managers putting messages on your queuesp Use OS security, Object Authority Manager (OAM) on WebSphere MQ user-written proceduresp What happens if DEAD letter Queue is not defined?p If dead letter queue are not defined the Messages are placed on the Transmission Queue and the Queue Manager become Inactivep Explain Remote queue definitions? Advantages?p These are definitions for queues that are owned by another queue managerp ñ " The advantage of remote queue definitions is that they enable an application to put a message to a remote queue without having to specify the name of the remote queue or the remote queue manager, or the name of the transmission queue. This gives you location independence.p
What happens if channel terminates when fast non-persistent messages are in transit?p If a channel terminates while fast, non-persistent messages are in transit, the messages are lost and it is up to the application to arrange for their recovery if required. If the receiving channel cannot put the message to its destination queue then it is placed on the dead letter queue, if one has been defined. If not, the message is discarded.p What happens when a message cannot be delivered?p Message-retry· If the MCA is unable to put a message to the target queue for a reason that could be transitory (for example, because the queue is full), the MCA has the option to wait and retry the operation laterp Return-to-sender· If message-retry was unsuccessful, or a different type of error was encountered, the MCA can send the message back to the originatorp Dead-letter queue· If a message cannot be delivered or returned, it is put on to the dead-letter queue (DLQ). You can use the DLQ handler to process the messagep Recovery scenario ±Disk Drive Full, damaged Queue manager object, Damaged single object, Automatic media recovery failurep MQ ensures that messages are not lost by maintaining records (logs) of the activities of the queue managers that handle the receipt, transmission, and delivery of messagesp How to Process Messages from the Dead-letter-Queue?p We can Process the DLQ messages using runmqdlq command for sending messages to the destination Queues or target Queues. Use the runmqdlq command to start the dead-letter queue (DLQ) handler, which monitors and handles messages on a dead-letter queue. p runmqdlqQNameQMgrNamep Use the Dead-Letter-Queue-Handler to perform various actions on selected messages by specifying a set of rules that can both select a message and define the action to be performed on that message. p The runmqdlq command takes its input from stdin. When the command is processed, the results and a summary are put into a report that is sent to stdout.p c 0G 0 p Reason fieldp What is completion code(MQCC) and reason code(MQRC)?
p
Completion code gives the status of the current transaction it can be 0, Ô, 2. 0- for Successful completion (MQCC_OK), Ô- Warning (MQCC_WARNING), 2- call failed (MQCC_FAILED). Reason code is that which gives the reason for which the transaction fails it can be MQRC_NONE, MQRC_BACKED_OUT etc.p
What is Correl ID?p This is a byte string that the application can use to relate one message to another, or to relate the message to other unit of work that the application is performing. The correlation identifier is a permanent property of the message, and persists across restarts of the queue managerp Explain commit and Back Out units of work?p When a program puts a message on a queue within a unit of work, that message is made visible to other programs only when the program commits the unit of work. p Commit· To commit a unit of work, all updates must be successful to preserve data integrity. If the program detects an error and decides that the put operation should not be made permanent, it can back out the unit of work.p Back Out· When a program performs a back out, WebSphere MQ restores the queue by removing the messages that were put on the queue by that unit of work. The way in which the program performs the commit and back out operations depends on the environment in which the program is runningp BackoutCount (MQLONG)?
p
This is a count of the number of times that the message has been previously returned by the MQGET call as part of a unit of work, and subsequently backed out. BackoutCount is the number of times the application tried and failed to put the messages in the Queuep What is segmentation and explain segmentation Flag?p When a message is too big for a queue, an attempt to put the message on the queue usually fails. Segmentation is a technique whereby the queue manager or application splits the message into smaller pieces called segments, and places each segment on the queue as a separate physical message. The application that retrieves the message can either retrieve the segments one by one, or request the queue manager to reassemble the segments into a single message that is returned by the MQGET call.p What are Namelist? when do you use it?
p
A namelist is a WebSphere MQ object that contains a list of other WebSphere MQ objects. Typically, namelists are used p àBy trigger monitors, where they are used to identify a group of queues.p àNamelists are also used with queue manager clusters to maintain a list of clusters referred to by more than one WebSphere MQ object.p àThe advantage of using a namelist is that it is maintained independently of applications; it can be updated without stopping any of the applications that use it. Also, if one application fails, the namelist is not affected and other applications can continue using it. Namelists are also used with queue manager clusters to maintain a list of clusters referred to by more than one WebSphere MQ objectp
c p The name service is an installable service that provides support to the queue manager for looking up the name of the queue manager that owns a specified queue.p c 0 8 a 9 $ c 8 a 9 p Local unit of work· Units of work that involve only the queue manager are called local units of work. Syncpoint coordination is provided by the queue manager itself (internal coordination) using a singlephase commit process.p Use global units of work when you also need to include updates to resources belonging to other resource managers. Here the coordination can be internal or external to the queue manager uses a two-phase commitp How will we start a command server?
p
Depending on the value of the queue manager attribute, SCMDSERV, the command server is either started automatically when the queue manager starts, or must be started manually. p Start· Using strmqcsvsaturn.queue.manager where saturn.queue.manager is the QM namep Display· dspmqcsv Stop· endmqcsvp c ºº$ ñ0.! ! ºº
$ p Stop and restart the queue manager, stop and restart command server (A command server processes command messages) and channel programs p What is a MQ Series Queue manager Configuration file (qm.ini)?
p
A queue manager configuration file (qm.ini) to effect changes for specific queue managers. There is one qm.ini file for each queue manager on the node. (A queue manager configuration file, qm.ini, contains config information relevant to a specific queue manager. There is one queue manager configuration file for each queue manager. The qm.ini file is automatically created when the queue manager with which it is associated is created. For example, the path and the name for a configuration file for a queue manager called QMNAME is·/var/mqm/qmgrs/QMNAME/qm.ini)p What is name transformation in naming a Queue manager Configuration File?p A qm.ini file is held in the root of the directory tree occupied by the queue manager. For example, the path and the name for a configuration file for a queue manager called QMNAME is· /var/mqm/qmgrs/QMNAME/qm.ini A directory name is generated based on the queue manager name. This process is known as name transformation.p
What is a Websphere MQ configuration file (mqs.ini)?
p
Contains information relevant to all the queue managers on the node. It is created automatically during installation (The WebSphere MQ configuration file, mqs.ini, contains information relevant to all the queue managers on the node. It is created automatically during installation. The mqs.ini file for WebSphere MQ for UNIX systems is in the /var/mqm directory. It contains· v The names of the queue managers v The name of the default queue manager The location of the files associated with each of them)p How can we edit the configuration files?
p
Automatically using commands that change the configuration of queue managers on the node, Manually using a standard text editorp When security checks are made?p Connecting to the queue manager (MQCONN or MQCONNX calls), Opening the object (MQOPEN or MQPUTÔ calls), Putting and getting messages (MQPUT or MQGET calls), Closing the object (MQCLOSE) p What is FFST?
p
First Failure Support Technology For MQSeries for UNIX systems, FFST information is recorded in a file in the /var/mqm/errors directory. These errors are normally severe, unrecoverable errors, and indicate either a configuration problem with the system or an MQSeries internal error. The files are named AMQnnnnn.mm.FDC, where· nnnnn Is the ID of the process reporting the error mm Is a sequence number, normally 0 When a process creates an FFST record, it also sends a record to syslog. The record contains the name of the FFST file to assist in automatic problem trackingp Creating Damaged Objects Using Log files?p Ô.Rcdmqimg· Use this command to write an image of an object, or group of objects, to the log for use in media recovery. This command can only be used when using linear logging.p Use the associated command rcrmqobj to recreate the object from the image.
p
2.Rcrmqobj· Use this command to recreate an object, or group of objects, from their images contained in the log. This command can only be used when using linear loggingp Use the associated command, rcdmqimg, to record the object images to the log.p £
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p
Restart recovery· When you stop WebSphere MQ in a planned way.p Crash recovery· When a failure stops WebSphere MQ.p Media recovery· To restore damaged objects.p
What are the locations and files of the Error Logging?p MQ Series Level Errorsp C· ProgramFiles IBM WebSphere MQ errorsà AMQERR0Ô.LOG, AMQERR02.LOG, AMQERR03.LOGp Qmanager Level errorsp C· ProgramFiles IBM WebSphere AMQERR03.LOGp
MQ Qmgrs errorsà
AMQERR0Ô.LOG,
AMQERR02.LOG,
errorsp What are the different types of security services available in MQ Series?p Identification & Authenticationp Access control à The access control service protects critical resources in a system by limiting access only to authorized users and their applications.p Confidentiality à The confidentiality service protects sensitive information from unauthorized disclosurep Data integrity à The data integrity service detects whether there has been unauthorized modification of data. There are two ways in which data might be altered· accidentally, through hardware and transmission errors, or because of a deliberate attack, Non-repudiation.p º p Ô.setmqaut· Command used to change the authorizations to a profile, object or class of objects. Authorizations can be granted to, or revoked from, any number of principals or groups. p 2.dspmqaut· Command to display the current authorizations to a specified object. If a user ID is a member of more than one group, this command displays the combined authorizations of all the groups.p Only one group or principal can be specified.p 3.dmpmqaut· Command to dump the current authorizations to a specified object.p What are the different methods handled by MQ Series for securing a message?p Cryptography Message digestsp Digital signatures Digital certificatesp Public Key Infrastructure (PKI)
p
What is Cryptography, Why and where it is used in MQ Series?p Cryptography is the process of converting between readable text, called plaintext, and an unreadable form, called cipher text.p The sender converts the plaintext message to cipher text. This part of the process is called encryption (sometimes encipherment).The cipher text is transmitted to the receiver. The receiver converts the cipher text message back to its plaintext form. This part of the process is called decryption (sometimes decipherment).p The conversion involves a sequence of mathematical operations that change the appearance of the message during transmission but do not affect the content. Cryptographic techniques can ensure confidentiality and protect messages against unauthorized viewing (eavesdropping), because an encrypted message is not understandable. Digital signatures, which provide an assurance of message integrity, use encryption techniques.p What is a Message Digest, Digital Signature and Digital Certificate?p Message digest· Is also known as a Message Authentication Code (MAC), because it can provide assurance that the message has not been modified. The message digest is sent with the message itself. The receiver can generate a digest for the message and compare it with the sender¶s digest. If the two digests are the same, this verifies the integrity of the message. Any tampering with the message during transmission almost certainly results in a different message digest.p Digital signature· Is formed by encrypting a particular representation of a message the encryption uses the private key of the signatory and, for efficiency, usually operates on a message digest rather than the message itself. Digital signatures vary with the data being signed, unlike handwritten signatures, which do not depend on the content of the document being signed. If two different messages are signed digitally by the same entity, the two signatures differ, but both signatures can be verified with the same public key, that is, the public key of the entity that signed the messages.p Digital certificates· Provide protection against impersonation, because a digital certificate binds a public key to its owner, whether that owner is an individual, a queue manager, or some other entity. Digital certificates are also known as public key certificates, because they give you assurances about the ownership of a public key when you use an asymmetric key scheme.p What is a Secure Sockets Layer (SSL), where it is used?p The Secure Sockets Layer (SSL) provides an industry standard protocol for transmitting data in a secure manner over an insecure network. The SSL protocol is widely deployed in both Internet and Intranet applications. SSL defines methods for authentication, data encryption, and message integrity for a reliable transport protocol, usually TCP/IP.p What are Cipher Suites and Cipher Specs in SSL?p Cipher Suite· Is a suite of cryptographic algorithms used by an SSL connection. A suite comprises three distinct algorithms. The key exchange and authentication algorithm, used during the SSL handshake. The encryption algorithm, used to encipher the data.The MAC (Message Authentication Code) algorithm, used to generate the message digest.p
Cipher Spec· Identifies the combination of the encryption algorithm and MAC algorithm. Both ends of an SSL connection must agree the same CipherSpec to be able to communicate.p What are the steps to be followed in working with SSL on an UNIX environment?p Ô.Setting up a key repository 2.Working with a key repositoryp 3.Obtaining personal certificates 4.Managing digital certificatesp 5.Configuring for cryptographic hardware 6.Mapping DNs to user IDsp 7.Adding personal certificates to a key repositoryp Websphere MQ installation naming consideration?p Ensure that the machine name does not contain any spaces. If you insatall in such a machine you cannot create and Queue managers. Names for userId and group must no longer that 20 charactersp What is CCSID?
p
This defines the character set of character data in the message. If you want to set this character set to that of the queue manager, you can set this field to the constant MQCCSI_Q_MGR or MQCCSI_INHERIT. When you get a message from a queue, compare the value of the CodedCharSetId field with the value that your application is expecting. If the two values differ, you might need to convert any character data in the message or use a data-conversion message exit if one is availablep º " Communication Paths between Queue Managers.p £ p V SYSTEM.DEFAULT.LOCAL QUEUE SYSTEM.DEFAULT.MODEL.QUEUEp SYSTEM.DEFAULT.REMOTE.QUEUE SYSTEM.DEFAULT.ALIAS.QUEUEp SYSTEM.DEFAULT.INITIATION.QUEUE SYSTEM.DEAD.LETTER.QUEUEp º V SYSTEM.CHANNEL.INITQ SYSTEM.CHANNEL.SYNCQp V SYSTEM.ADMIN.ACCOUNTING.QUEUEp SYSTEM.ADMIN.ACTIVITY.QUEUEp SYSTEM.ADMIN.COMMAND.QUEUEp SYSTEM.ADMIN.STATISTICS.QUEUEp SYSTEM.ADMIN.TRACE.ROUTE.QUEUEp º SYSTEM.AUTO.RECEIVER SYSTEM.AUTO.SVRCONNp
SYSTEM.DEF.CLUSRCVR SYSTEM.DEF.CLUSSDRp SYSTEM.DEF.RECEIVER SYSTEM.DEF.REQUESTERp SYSTEM.DEF.SENDER SYSTEM.DEF.SERVER
p
SYSTEM.DEF.SVRCONNp ÿ SYSTEM.DEFAULT.LISTENER.TCPp SYSTEM.DEFAULT.LISTENER.SPXp SYSTEM.DEFAULT.LISTENER.NETBIOS
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SYSTEM.DEFAULT.LISTENER.LU62p Ñ î SYSTEM.DEFAULT.PROCESSp d
î SYSTEM.DEFAULT.SERVICE SYSTEM.BROKERp
À ÿ SYSTEM.DEFAULT.NAMELIS
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M V SYSTEM.ADMIN.CHANNEL.EVENTp SYSTEM.ADMIN.LOGGER.EVENTp SYSTEM.ADMIN.PERFM.EVENTp SYSTEM.ADMIN.QMGR.EVENTp What are advantages of creating Aliases? Why do we create Alias?
p
When sending messages· Re mapping the queue-manager name when sending messages, Altering or specifying the transmission queue when sending messages, Determining the destination when receiving messages, Using a queue manager as a gateway into the cluster. Gives different application different levels of access authority to the target Queue Allows different applications to work with the same queue in different way Simplifies maintenance, migration and workload balancep c 8 9 p Requires a Connection handler (Hconn), a Queue handler (Hobj), a description of the message that you want to put on the queue (MQMD), Control information, message length, the message data itselfp Getting messages for a queue?
p
You can remove a message from the queue so that other programs can no longer see the message, you can copy a message, leaving the original message on the queue. This is known as browsing. You can remove the message once you have browsed it. In both cases, you use the MQGET call, but first
your application must be connected to the queue manager, and you must use the MQOPEN call to open the queuep What happens when a message is put in a PUT-INHIBITED Queue?p The messages are put in the dead letter queue. If a channel is unable to put a message to the target queue because that queue is full or put inhibited, the channel can retry the operation a number of times (specified in the message-retry count attribute) at a given time interval (specified in the message-retry interval attribute). Alternatively, you can write your own message-retry exit that determines which circumstances cause a retry, and the number of attempts made. The channel goes to PAUSED state while waiting for the message-retry interval to finishp What is syncpoints?
p
Syncpoint coordination is the process by which units of work are either committed or backed out with data integrity. The decision to commit or back out the changes is taken, in the simplest case, at the end of a transaction. However, it can be more useful for an application to synchronize data changes at other logical points within a transaction. p These logical points are called syncpoints (or synchronization points) and the period of processing a set of updates between two syncpoints is called a unit of workp In-doubt Channels? How will you resolve this ?p An in-doubt channel is a channel that is indoubt with the remote channel about which messages has been sent and receivedp d We can do Commit or Rollback the messages which are in doubt.p "p Queue open failed?p *Reason· On an MQCONN or MQCONNX call, the value specified for the QMgrName parameter is not valid or not knownp *Resolution· we must correct the configuration information
p
Queue not found?p *Reason Code 2085 MQRC_UNKNOWN_OBJECT_NAME
p
*Resolution· check for the Queue name in the QManager if not found define it. Messages sent to DLQ?p *Reason code· 22Ô8 Message too big for Channel
p
p
*Investigation· Examine the contents of the dead-letter queue. Each message is contained in a structure that describes why the message was put to the queue, and to where it was originally addressed. Also look at previous error messages to see if the attempt to put messages to a deadletter queue failed.p *Resolution· change the channel size as required, if the channel is a cluster channel then do a REFRESH cluster so that it will reflect to the other QM¶s, then reprocess the messagep Message piling(FULL) up in a Queue?p *Investigation· Check for the log files (/var/mqm/qmgrs//errors/*.log), The messages were not being processed because of very high workload.p *Resolution· SSL
p
*Authentication failure·
p
The SSL client does not have a certificatep A certificate has expired or is not yet activep A certificate is not supportedp A certificate is corruptedp May be ssl version upgradationp Channel refuses to run or channel retry?p *Reason· A mismatch of name between a sending and receiving channels, Incorrect channel type specified, A receiver channel might be in stopped state, the connection might not be defined Correctly, there might be a problem with communication software.p *Resolution· Alter the Queue and REFRESH the cluster to reflect the change in the information stored in the partial repositoryp Handling messages more than 4 MB?p Increase the Queue and Queue manager MaxMsgLength attributes, Use segmented messages (Messages can be segmented by either the application or the Queue manager), use reference message.p DQM· DISTRIBUTED QUEUEING MANAGEMENTp Setuping& Controlling of Message Channel in Message Queuing for Q Managers on Distributed Systems.p
What is the SSL Version used in WMQ5.3?p Version 3.0p NPMSPEED FAST. What happens if the channel goes down?p Nonpersistent message speed (NPMSPEED) It is used to specify the speed at which nonpersistent messages are to be sent. It can take on two values either µnormal¶ or µfast¶. The default is µfast¶, which means that nonpersistent messages on a channel are not transferred within transactions. Non persistent messages are lost if there is a transmission failure or if the channel stops when the messages are in transit.p What is SSL?p Secure Sockets Layer (SSL) is a protocol designed to allow the transmission of secure data over an insecure network. SSL makes use of digital certificates to enable authentication of the partner. It also uses encryption to prevent eavesdropping and hash functions to enable detection of tampering. It can be used with both MCA channels for queue manager to queue manager communication and MQI channels for client applications connecting to a queue managerp What are the algorithms in SSL?p A CipherSuite is a suite of cryptographic algorithms used by an SSL connection. A suite comprises three distinct algorithms·p The key exchange and authentication algorithm, used during the SSL handshakep The encryption algorithm, used to encipher the datap The MAC (Message Authentication Code) algorithm, used to generate the message digestp c . p ñ" Web Sphere MQ enables you to start an application automatically when certain conditions on a queue are met. For example, you might want to start an application when the number of messages on a queue reaches a specified number. This facility is called p G . p :!5" A trigger event occurs every time that a message arrives on the application queue. Use this type of trigger if you want a serving program to process only one message, then end. p ü!." A trigger event occurs only when the number of messages on the application queue changes from zero to one. Use this type of trigger if you want a serving program to start when the first message arrives on a queue, continue until there are no more messages to process, then end. p -.G" A trigger event occurs only when the number of messages on the application queue reaches the value of the TriggerDepth attribute.p
What are the Trigger types available Explain?
p
ñ $º . p 9 In the case of application triggering the components are Application queue· This is the message queue associated with an application Process· A process definition defines the application to be used to process messages from the application queue. Initiation queue· The queue manager moitors the application queue. If the trigger type of the application queue is set to Every then whenever a message is put to the application queue, the q manager looks into the process definition and puts a message having the application name and other details to the initiation queue Trigger monitor· The trigger monitor gets the trigger message from the initiation queue and starts the program specified.p $9 For channel triggering the transmission queue is monitored and when messages are put in the transmission queue, the q manager puts a message in the channel initiation queue. The channel initiator is the program which monitors the initiation queue and starts the sender MCA. For the message to reach the target queue, the channel listener has to be running in the target queue managerp º . º ·p · Trigger ON
p
· Trigger type(first every depth)p · Trigger data(channel name which is to be fired)p · Initiation queue(SYSTEM.CHANNEL.INITQ)p º . "p Ô. The local queue manager places a message from an application or from a message channel agent (MCA) on the transmission queue.p 2. When the triggering conditions are fulfilled, the local queue manager places a trigger message on the initiation queue.p 3. The long-running channel initiator program monitors the initiation queue, and retrieves messages as they appear.p 4. The channel initiator processes the trigger messages according to information contained in them. This information may include the channel name, in which case the corresponding MCA is started.p 5. The channel listener running in the target q mgr starts the receiving MCAp ñ . º ·p
xp xp xp
Trigger ONp Trigger type (first every depth)p Initiation queue (SYSTEM.DEFAULT.INITIATION.QUEUE our own defined local queue)p
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Process (NOTEPAD)p
DEFINE QLOCAL (LQ) TRIGGER TRIGTYPE (EVERY) INITQ (IQ) PROCESS (NOTEPAD).p DEFINE PROCESS (NOTEPAD) APPLICID (NOTEPAD.EXE) APPLTYPE (WINDOWS)p Runmqtrm ±m QMÔ ±q IQp ñº; !#-!#º"ap Ô. When ever the message comes to triggered local queue, queue manager will fire trigger message with information called trigger type and the process definition (application which is to be triggered) in to the initiation queue (IQ) (our own queue).p 2. At the initiation queue a long running time program called trigger monitor will be watching (monitoring) the initiation queue.p 3. Whenever the trigger message occurs in the initiation the trigger monitor will pick the information and starts the application which is defined in the process.p What is a Trigger monitor?
p
A trigger monitor is a continuously - running program that serves one or more initiation queues. When a trigger message arrives on an initiation queue, the trigger monitor retrieves the message. The trigger monitor uses the information in the trigger message. It issues a command to start the corresponding application/channelp c p ñ"# "runmqtrm -m QMName -q Initiation QueueNamep #º "runmqtmc -m QMName -q Initiation QueueNamep
