I've created an administration domain on a Windows node, now I need to create a cluster and add that node into that cluster.How do I go about it?
There is no concept of "Cluster" (in a WMQ sense) with EMS, but there are notions of "connected EMS servers" (routes), and bridging of queues (bridges, not unlike WMQ remote queues). There is also the notion of "Multi-instance local HA".
You may want to :
Plan your EMS deployment strategy, to proper balance latency, availability, license cost and performance
Execute the plan by:
Seting up the local HA, with a shared FS if shared state is needed (here is my article on that)
Make use of the "Routes" feature of EMS to link your multiple EMS HA instances together (see page 569 of the user guide)
Note : If you have a limited number of instances but MASSIVE amount of clients, consider multicast OR another product (like FTL or RabbitMQ).
Related
We have multiple application environments (development, QA, UAT, etc) that need to connect to fewer provider environments through MQ. For example, the provider only has one test (we'll call it TEST1) environment to which all of the client application environments need to interact. It is imperative that each client environment only receives MQ responses to the messages sent by that respective environment. This is a high volume scenario so correlating message IDs has been ruled out.
Right now TEST1 has a queue set up and is functional, but if one of the client app's environments wants to use it the others have to be shut off so that messaging doesn't overlap.
Does MQ support a model having multiple clients connect to a single queue while preserving the client-specific messaging? If so, where is that controlled (i.e. the channel, queue manager, etc)? If not, is the only solution to set up additional queues for each corresponding client?
Over the many years I have worked with IBM MQ, I have gone back and forth on this issue. I've come to the conclusion that sharing a queue just makes life more difficult. Queues should be handed out like candy on Halloween. If an application team says that they have 10 components to their application then the MQAdmin should give them 10 queues. To the queue manager or server or CPU or hard disk, there is no difference in resource usage.
Also, use an MQ naming standard that makes sense and is easy to apply security to. i.e. for HR (Human Resource) department
HR.PAYROLL.SALARY
HR.PAYROLL.DEDUCTIONS
HR.PAYROLL.BENEFITS
HR.EMPLOYEE.DETAILS
HR.EMPLOYEE.REVIEWS
etc...
You could use a selector such as MQGET(where applname="myapp") or based on a specific user-defined property assuming the sender populates such a property but that's likely to be worse performance than any retrieval by msgid or correlid. Though you've not given any information to demonstrate that get-by-correlid is actually problematic.
And of course any difference between a test and production environment - whether it involves code or configuration - is going to be very risky.
You would not normally share a single destination queue between multiple different application types - multiple queues is far more standard.
Today we have our MQ installations primarely on mainframe, but are considering moving them to Windows or Linux instead.
We have three queue managers (qmgrs) in most environments. Two in a queue sharing group across two LPARs, and a stand-alone qmgr for applications that doesn't need to run 24/7. We have many smaller applications, which shares the few qmgrs.
When I read up on building qmgrs in Windows and Linux, I get the impression that most designs favor a qmgr or a cluster per application. Is it a no-go to build a general purpose qmgr for a hundred small applications on Windows/Linux?
I have considered a Multi instance Qmgr (active/passive) or a clustered solution.
What is considered best practice in a scenario, where I have several hundred different applications that needs MQ communication.
First off, you are asking for an opinion that is not allowed on StackOverflow.
Secondly, if you have z/OS (mainframe) applications using MQ then you cannot move MQ off the mainframe because there is no client-mode connectivity for mainframe applications. What I mean is that the mainframe MQ applications cannot connect in client mode to a queue manager running on a distributed platform (i.e. Linux, Windows, etc.). You will need to have queue managers on both mainframe and distributed platforms to allow messages to flow between the platforms. So, your title of "Moving IBM MQ away from mainframe" is a no go unless ALL mainframe MQ applications are moving off the mainframe too.
I get the impression that most designs favor a qmgr or a cluster per
application.
I don't know where you read that but it sounds like information from the 90's. Normally, you should only isolate a queue manager if you have a very good reason.
I have considered a Multi instance Qmgr (active/passive) or a
clustered solution.
I think you need to read up on MQ MI and MQ clustering because they are not mutually exclusive. MQ clustering has nothing to do with fail-over or HA (high-availability).
Here is a description of MQ clustering from the MQ Knowledge Center.
You need to understand and document your requirements.
What failover time can you tolerate?
With Shared queue on z/OS if you kill one MQ - another MQ can continue processing the messages within seconds. Applications will have to detect the connection is broken and reconnect.
If you go for a mid range solution, it may take longer to detect a queue manager has gone down, and for the work to switch to an alternative. During this time the in-transit messages will not be available.
If you have 10 mid range queue managers and kill one of them, applications wich were connected to the dead queue manager can detect the outage and reconnect to a different queue manager within seconds, so new messages will have a short blip in throughput. Applications connected to the other 9 queue managers will not be affected, so a smaller "blip" overall.
Do you have response time criteria? So enterprises have a "budget" no more than 5 ms in MQ, no more than 15 ms in DB2 etc.
Will having midrange affect response time, for example is there more or less network latency between clients and servers.
Are you worried about confidentiality of data. On z/OS you can have disk encryption enabled by default.
Are you worried about security of data, for example use of keystores, and having stash files (with the passwords of the keystore) sitting next to the keystore. Z/OS is better than mid range in this area.
You can have tamper proof keystores on z/OS and midrange.
Scaling
How many distributed queue managers will you need to handle the current workload, and any growth (and any unexpected peaks). Does this change your operational model?
If you are using AMS, the maintenance of keystores is challenging. If you add one more recipient, you need to update the keystore for all userids that use the queue- on all queue managers. With z/OS You update one key ring per queue manager.
How would the move to midrange affect your disaster recovery? It may be easier (just spin up a new queue manager) with midrange, or harder - you need to create the environment before you can spin up a new queue manager.
What is the worst case environment, for example the systems you talk to - if they went down for a day. Can your queue managers hold/buffer the workload?
If you had a day's worth of data, how long would it take to drain it and send it?
Where are your applications? - if you have applications running on z/OS (for example , batch, CICS, IMS, WAS) they all need a z/OS queue manager on the same LPAR. If all the applications are not on z/OS then they can all use client mode to access MQ.
How does security change? (Command access, access to queues)
Currently intra-region we achieve HA (hot/hot) between applications by using exclusive queues to ensure 1 application is Active and the rest are standby.
How do I achieve the same thing across region when the appliances are linked via cspf neighbour links? As queues are local to an appliance the approach above doesn't work.
Not possible using your design of CSPF neighbors - they are meant for direct messages and not guaranteed.
Are you able to provide more details about your use case?
Solace can easily do active/standby across regions using Data Center Replication.
Solace can also allow consumers to consume messages from the endpoints on both the active and standby regions by Allowing Clients to Connect to Standby Sites. However this means two consumers will be active - one on the active and one on the standby site.
We have IBM MQ V7.1.0 installed and working in production. Can I create a queue manager in the production environment and perform stress testing on that. Will that impact other queue managers that are existing. Is there any way I can create separate environment from the installed IBM MQ (Not installing the MQ again).
MQ is IO intensive, so performance mostly depends on the storage where the log and data directories of your queue managers are and on the capacity of the network interface(s) of your host.
If you configure the queue managers to have separate (both logically and phisically) storages for the data and log directories of each, and you provide enough bandwidth for the machine to handle the message load of multiple queue managers, performance impact of the queue managers on each other should be minimal.
That said, I don't think it's a good idea to do stress testing on an in use production environment, as the goal of stress testing is to find the load which "breaks" the system.
When I read about HA in Websphere MQ I always come to the point, when the best practise is to create two Queue Managers handling the same queue and use out-of-the-box load balancing. Therefore, when one is down, the other takes over his job.
Well, this is great but what about the messages in the queue that belong to the Queue Manager that went down? I mean do these messages reside there (when queue is persistent of course) until QM is up and running again?
Furthermore, is it possible to create a common storage for this doubled Queue Managers? Then no message would wait for the QM to be up. Every message would be delivered in the proper order. Is this correct?
WebSphere MQ provides different capabilities for HA, depending on your requirements. WebSphere MQ clustering uses parallelism to distribute load across multiple instances of a queue. This provides availability of the service but not for in-flight messages.
Hardware clustering and Multi-Instance Queue Manager (MIQM) are both designs using multiple instances of a queue manager that see a single disk image of that queue manager's state. These provide availability of in-flight messages but the service is briefly unavailable while the cluster fails over.
Using these in combination it is possible to provide recovery of in-flight messages as well as availability of the service across multiple queue instances.
In hardware cluster model the disk is mounted to only one server and the cluster software monitors for failure and swaps the disk, IP address and possibly other resources to the secondary node. This requires a hardware cluster monitor such as PowerHA to manage the cluster.
The Multi-Instance QMgr is implemented entirely within WebSphere MQ and needs no other software. It works by having two running instances of the QMgr pointing to the same NFS 4 shared disk mount. Both instances compete for locks on the files. The first one to acquire a lock becomes the active QMgr. Because there is no hardware cluster monitor to perform IP address takeover this type of cluster will have multiple IP addresses. Any modern version of WMQ allows for this using multi-instance CONNAME where you can supply a comma-separated list of IP or DNS names. Client applications that previously used Client Channel Definition Tables (CCDT) to manage failover across multiple QMgrs will continue to work and CCDT continues to be supported in current versions of WMQ.
Please see the Infocenter topic Using WebSphere MQ with high availability configurations for details of hardware cluster and MIQM support.
Client Channel Definition Table files are discussed in the Infocenter topic Client Channel Definition Table file.