I am seeing an issue in MQ cluster infrastructure where messages pile
up in SYSTEM.INTER.QMGR.PUBS which is present in a queue manager with
cluster topics defined.
Infocenter says "In a publish/subscribe cluster, those publications are
targeted at the SYSTEM.INTER.QMGR.PUBS queue on the remote queue
managers that host the subscriptions."
I would like to know how the message flow works with SYSTEM.INTER.QMGR.
PUBS queue in a queue manager with Topics & subscriptions defined as
Cluster Topics & local susbcriptions
Local Topics & local subscriptions
Can anyone help here to understand whether messages flow through SYSTEM.INTER.QMGR.PUBS queue if Topics are defined local to a queue manager?
I would expect messages flow through the SYSTEM.INTER.QMGR.PUBS queue of a queue manager when the queue manager has local subscriptions to a topic, which is published to by publishers connected to a remote queue manager, or when the queue manager is a topic host in a cluster using topic host routing, or when the queue manager is member of a publish/subscribe hierarchy.
It doesn't matter whether the topic object is defined remotely or locally, messages will flow through this queue when the queue manager is on the route between remote publishers and subscribers.
http://www.ibm.com/support/knowledgecenter/SSFKSJ_8.0.0/com.ibm.mq.mon.doc/q005262_.htm%23q005262_?lang=en
The SYSTEM.INTER.QMGR.PUBS is made use if the Topics are defined in cluster and there are no local defined queue objects in the same queue manager for remote publishers(queues) to publish messages to cluster Topics.In this case all published messages pass through this queue to reach Topics.
But if the Topics are defined as local Topics are there are alias queue objects defined in the same queue manager which are mapped to Topics; then all remote publishers(queues) will publish to the alias queues defined and skip the SYSTEM.INTER.QMGR.PUBS. In this case this queue is not made use for publishing.
Related
this is what I want to achieve with IBM MQ:
I have a topic in place, and 2 different applications (A1,A2) subscribing the topic. each application has 2 instances, i.e. (A1-I1,A1-I2,A2-I1,A2-I2).
when a message (M1) is published to the topic, the message will be received by both applications A1 & A2. but within A1, only one instance (A1-I1 or A1-I2) can receive this message M1, the same goes to instances of A2.
is it possible with IBM MQ topics and JMS?
I have looked up shared subscription mentioned in the comment, but I find it (IBM MQ) has a limitation that the shared subscription can only be accessed by one JVM, i.e. two application instances can't access the the shared subscription at the same time, so I give up this purely pub/sub direction.
I managed to make it work by making the applications listen to the destination queue of subscription instead of directly subscription. I defined in the queue manager subscription SUB.A1 with destination queue of SUB.A1.QUEUE and subscription SUB.A2 with destination queue of SUB.A2.QUEUE. all instances of application A1 will listen to SUB.A1.QUEUE and A2 to SUB.A2.QUEUE. and everything works as expected.
The above setup is all applications connecting to the same queue manager. if there is a queue manager cluster of multiple QMs, just define the subscription destination queues as cluster queues and it will work as well
How can I use WebSphere Message broker instance to route messages between queues residing in two queue managers. The message broker instance can only be associated with one queue manager during creation time. So I create an MQInputNode and put messages to the specific source queue. My concern is to route this message to second queue residing in another queue manager using the same broker instance. How? I am using WebSphere Message Broker version 8.0.0.8. Not yet into IIB.
Below is a simple and efficient way of doing it.
Suppose, your broker is on QM1. You have a local queue in QM2 named LQ_QM2.
And you want the messages to go to LQ_QM2. Follow below steps:
At QM1, create a local queue of usage 'Transmission'. Let us name this transmission queue as "QM2".
At QM1, create a sender channel named "QM1.QM2" with proper connection name (Contains host(port) of target queue manager, for eg
10.1.5.2(1144)) and set transmission queue as QM2 (The one we created in step 1).
Create a receiver channel at QM2 named "QM1.QM2).
Now create a remote queue definition at QM1. Let's name it as RQ_LQ_QM2. Set remote queue property as LQ_QM2 and transmission queue
as QM2 and remote queue manager as QM2.
The messages which you want to send to the queue LQ_QM2 can now be written by the broker to RQ_LQ_QM2 in QM1 itself.
If you can't do the above MQ stuff and must use only Message broker capability then the way of doing it in WMB 8 would be to use Java and write an MQ client code using the MQ API libraries. You will then establish remote connection with the remote queue manager using SVRCONN channel and put messages on the remote queue manager's queue.
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.
Looking at the sample codes it seems I need queue manager and queue name to setup MQ through code. What is difference between those and where I can get those values from? Any suggestion?
MQTopicConnectionFactory cf = new MQTopicConnectionFactory();
// Config
cf.setHostName("localhost");
cf.setPort(1414);
cf.setTransportType(JMSC.MQJMS_TP_CLIENT_MQ_TCPIP);
cf.setQueueManager("QM_thinkpad");
cf.setChannel("SYSTEM.DEF.SVRCONN");
MQTopicConnection connection = (MQTopicConnection) cf.createTopicConnection();
MQTopicSession session = (MQTopicSession) connection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
MQTopic topic = (MQTopic) session.createTopic("topic://foo");
MQTopicPublisher publisher = (MQTopicPublisher) session.createPublisher(topic);
MQTopicSubscriber subscriber = (MQTopicSubscriber) session.createSubscriber(topic);
You connect to a queue manager which may host many different queues. So yes, an application generally needs access to a queue manager and then specific queues on that queue manager. I suggest you can look at the Stack Overflow info for the websphere-mq tag to help get you started. The names of those objects should be known by your application architect/developer or can be confirmed with the MQ admin.
A Queue is a container for messages. Business applications that are connected to the Queue Manager that hosts the queue can retrieve messages from the queue or can put messages on the queue. We have difference types of Queues as follows:
Local Queue: A local queue is a definition of both a queue and the set of messages that are associated with the queue. The queue manager that hosts the queue receives messages in its local queues
Remote Queue: Remote queue definitions are definitions on the local Queue Manager of queues that belong to another queue manager. To send a message to a queue on a remote queue manager, the sender queue manager must have a remote definition of the target queue.
Alias Queue: Alias queues are not actually queues; they are additional definitions of existing queues. You create alias queue definitions that refer to actual local queues but you can name the alias queue definition differently from the local queue (the base queue). This means that you can change the queues that an application uses without needing to change the application; you just create an alias queue definition that points to the new local queue.
Source
Before going to connect Queue, we must start a queue manager.The queue manager has a name, and applications can connect to it using this name. The queue manager owns and manages the set of resources that are used by WebSphere MQ.
Page sets that hold the WebSphere MQ object definitions and message data
Logs that are used to recover messages and objects in the event of queue manager failure
Processor storage
Connections through which different application environments (CICS®, IMS™, and Batch) can access the WebSphere MQ API
The WebSphere MQ channel initiator, which allows communication between WebSphere MQ on your z/OS system and other systems
Source