We have 2 MQ Queue Managers, and one WAS server. We need to send message from QM01 to QM02 and then from QM02 to WAS server.
For doing this we have built a sender channel between QM01 and QM02, message is placed over a remote queue which has a definition of another remote queue for the WAS Service Integration Bus queue.
Is there any harm in sending message as following;
Remote Queue on QM01 ==> Remote Queue on QM02 ==> Queue on SI
Bus on WAS
Yes, this is a perfectly valid method of hopping messages from one queue manager to another, especially if the queue managers are not clustered. There is no harm to the message or the environment with this approach, though it does has a little more administrative overhead as opposed to a cluster-based solution.
Related
I currently have an XMIT queue with a SDR channel pointed to a QREMOTE. In a scenario where either the local or remote channels are down, I would like to forward the messages on the XMIT queue to the DLQ. It appears that in this scenario, messages remain on the XMIT queue until the channel is reestablished. Is it possible to do this?
I'm thinking not. From an ibm red paper: http://www.redbooks.ibm.com/redpapers/pdfs/redp0021.pdf
A transmission queue is a local queue with the USAGE(XMITQ) attribute
configured. It is a staging point for messages that are destined for a
remote queue manager. Typically, there is one transmission queue for
each remote queue manager to which the local queue manager might
connect directly. If the destination is unavailable, messages build up
on the transmission queue until the connection can be successfully
completed. Transmission queues are transparent to the application.
When an application opens a remote queue, the queue manager
internally creates a reference to the relevant transmission queue and
messages are put there.
I have two machines - Machine 1 and Machine 2. Machine 1 has one queue manager QM1 and a broker(integration server) BR1 and Machine 2 has one queue manager QM2 and a broker(integration server) BR2 . I want to make a cluster between QM1 AND QM2. I had created a remote cluster queue named INVENTQ in QM2 .The problem is that I am able to successfully post any message on any queue manager and I am able to see the corresponding message on INVENTQ in QM2 . But I want the architecture to be in such a way that I am able to receive the message from the queue from any of the queue managers in addition to the queue manager in which the queue INVENTQ is created i.e QM2 . Can anybody guide me in this ?
MQ does not have a 'remote get' capability - ie you cannot use local bindings to a queue manager and get a message from another queue manager. If you want to do this, you need to use client bindings to go to the queue manger where the message resides directly.
At MQPUT time, a decision has to be made (on the putting queue manager), where to forward the message to (e.g. which local queue, or which transmission queue to pass it to another queue manager).
In a cluster setup, if you have a queue defined on one queue manager and put it the cluster, anyone from any of the clustered queue managers can put to it as though it was a local queue. However their MQPUTs result in the message arriving (via the cluster channels), onto the one particular instance. Therefore from a different queue manager whilst you can put the message to the queue, you cannot get it.
You could have a queue with the same name defined on multiple queue managers and clustered, as per #JoshMc's suggestion, but this means that at MQPUT time, the message is routed to one, and only one, instance of that queue - if it was routed to the remote queue manager clustered definition you still would not be able to get it from the local queue manager. Imagine you had a cluster of 3 qmgrs. You can create a clustered queue called 'FRED' in 2 of them. All of them can put to FRED - but 2 of them will default to put to their local queue only (unless you set CLWLUSEQ=ANY), the other will (usually) alternate between the 2 remote instances. Each queue will definitely have different messages on.
https://www.ibm.com/developerworks/community/blogs/messaging/entry/Undestanding_on_MQ_Cluster_Work_Load_Management_Algorithm_and_Attributes?lang=en
Can somebody help to understand the basic of these 3 queues with example.when do we use all 3
Perhaps a more simple explanation: Think of a local queue as a queue which exists on the queue manager it is defined.. you can PUT and GET messages off a local queue. A remote queue is like a pointer to a queue on another queue manager which is usually on different host. Therefore messages can be PUT to it (and they will usually arrive on a local queue at that remote host) but you cannot GET messages from a remote queue.
Simply put, a queue manager only ever hosts messages on local or transmition queues on that queue manager. If you want to go to another queue manager, you can use definitions which tell the queue manager that the 'put' is running on, how to route the message to a destination queue manager - however this ends up with a message on a transmit queue which is then picked up and sent down a channel towards that destination. Alias queues are just an opportunity to use a different name for another queue. Remote queues are definitions on one queuemanager with information about where the message should be routed.
MQ documentation:
https://www.ibm.com/support/knowledgecenter/SSFKSJ_8.0.0/com.ibm.mq.explorer.doc/e_queues.htm
Another description:
https://www.scribd.com/doc/44887119/Different-Types-Queues-in-Websphere-MQ
A queue is known to a program as local if it is owned by the queue manager to which the program is connected; the queue is known as remote if it is owned by a different queue manager. The important difference between these two types of queue is that you can get messages only from local queues. (You can put messages on both types of queue.)
References:
https://www.ibm.com/support/knowledgecenter/en/SSFKSJ_7.0.1/com.ibm.mq.csqzal.doc/fg10950_.htm
https://www.ibm.com/support/knowledgecenter/SSFKSJ_8.0.0/com.ibm.mq.explorer.doc/e_queues.htm
An application which is connected to a local QueueManager which host a queue, So that queue will be local queue for that application. An application which is connected to a QueueManager which is located remotely and that host a queue that queue will be remote queue. we should always keeps in mind that we always read the message from the local queue. A message put on the remote queue, will be routed to local queue through the object defined on the local queue thrugh the channel and the transmission queue.
Why we use Transmission queue to store message in Sending a message to remote queue as we can also store the message in local queue.
So creating a transmission queue is taking memory and space.
You need to learn more about MQ. A good place to start is the MQ Primer.
You will learn that a transmission queue (aka XMITQ) is a local queue that is used by the MCA (Message Channel Agent) to transfer messages from the local queue manager to the remote queue manager. Messages should only be in the XMITQ very briefly.
With WebSphere MQ, where is a message addressed to a remote queue manager and PUT under syncpoint control stored until MQCMIT is issued?
Messages that are addressed to a remote queue manager resolve to a transmit queue. Which transmit queue they resolve to depends on how the message will be sent to the remote QMgr. The message will resolve locally to either a user-defined transmit queue for a SDR or SVR channel, or it will resolve to SYSTEM.CLUSTER.TRANSMIT.QUEUE for a clustered channel.
For any message that is put under syncpoint, the message is written to the transaction logs and, if the message is persistent, to the queue file. The queue depth increases to reflect that the message is in the queue but the message is not made available to other programs (such as the channel agent) until the COMMIT occurs.
So if your message is going to a clustered queue manager and you PUT under syncpoint, you will see the depth of the cluster transmit queue increase. At that point the message is at least in the transaction log and possibly also written to the queue file. As soon as the message is committed, it becomes available to the channel.