Choose messaging providers for a mixed environment

Choose messaging providers for a mixed environment

If our existing or planned messaging environment involves both IBM MQ and WebSphere Application Server systems, choose between the default messaging provider, the IBM MQ messaging provider, or a mixture of the two, by considering our messaging requirements, the business environment, and the needs of each messaging application.

For messaging between application servers, with interaction with an IBM MQ system, we can use the default messaging provider or the IBM MQ provider. Neither provider is necessarily better than the other. The choice of providers depends primarily on factors relating to the business environment and planned changes to that environment, and also on what each JMS application needs to do. oreover, these two types of messaging providers are not mutually exclusive:

We can configure both types of providers within one cell.
Different applications can use the same, or different, providers.

Configuring and managing our messaging infrastructure is simpler if we use just one provider. If our messaging is primarily in IBM MQ, we should probably choose the IBM MQ messaging provider. Similarly, if our messaging is primarily in WAS, we should probably choose the default messaging provider.

If our business environment does not clearly indicate that we should use just one provider, then we should consider using a mixture of the two, and choosing the most appropriate messaging provider for each application. A useful way of doing this is to identify the types of destinations (service integration bus, or IBM MQ queue or topic) that the application is using. If the application uses only bus destinations, the natural choice is to use the default messaging provider (solution "DMP"). If the application needs to communicate with one or more IBM MQ destinations, we can choose any of the following solutions depending upon the business environment, usage scenarios, and system topologies:

Use the IBM MQ messaging provider (solution "MQP").
Use the default messaging provider to integrate an IBM MQ network as a foreign bus, using IBM MQ links (solution "DMP interop, foreign bus").
(Deprecated) Use the default messaging provider to integrate a IBM MQ server (an IBM MQ queue manager or queue-sharing group) as a bus member (solution "DMP interop bus member").

For more information about these solutions, see Interoperation with IBM MQ: Comparison of key features.

To help us choose between these solutions, several of the following steps contain tables in which each row represents a business or system requirement, and asterisks (*) indicate the solutions that are likely to be most effective for meeting the requirement. These tables are designed to provide general guidance, rather than to identify precise solutions. Most requirements have multiple possible solutions, and the absence of an asterisk does not necessarily mean that we cannot use that solution. To derive best guidance from using each of these tables:

Focus on the rows that reflect your most important requirements.
For all the rows that you consider, count the number of asterisks for each solution.

The solutions with the largest number of asterisks are likely to be the most effective.

Tasks

If we have limited experience of IBM MQ or WAS, and are trying to decide which product best meets our messaging needs, see Comparison of WAS and IBM MQ messaging.
Whichever of these products we choose as the main focus for our messaging, we can still use either the default messaging provider or the IBM MQ provider for interoperation between the products.
Consider the business environment, to see if we can use just one provider.
In deciding which provider to use, consider the following constraints:

The current and future messaging requirements
The existing messaging infrastructure
The skill set that we have in our organization

If the majority of our messaging is today performed in IBM MQ, continue with that approach and configure IBM MQ as an external JMS provider (that is, use the IBM MQ messaging provider) in WAS. If the JMS requirements of our WAS applications are limited, it is debatable whether using a service integration bus for those applications gives sufficient benefit.

If we have messaging applications in WAS that have no requirement to interoperate with the IBM MQ network, use the default messaging provider (the service integration bus). If our WAS messaging requirements demand a tighter integration with WAS, the service integration bus provides the following benefits:

Integrated administration
WAS high availability capabilities
WAS scalability

If we choose to use the default messaging provider to interoperate between service integration and IBM MQ, be aware that there is an added cost involved in converting messages between service integration format and IBM MQ format.

Also consider the following messaging scenarios:

A large installed backbone of IBM MQ queue managers, perhaps with message broker product.
To use WAS to run a newly introduced messaging application, we can deploy a WAS (JMS) messaging application that will exchange messages with an existing application that uses an IBM MQ queue or topic.

A WAS installation, perhaps with existing web and enterprise applications, but no WAS messaging application.
If we have no existing messaging infrastructure, we can deploy a WAS (JMS) messaging application to exchange messages with an existing WAS messaging application that uses a service integration bus destination.

An infrastructure that uses WAS to connect WAS messaging applications.
Introduce WAS (JMS) messaging between a pair of WAS applications.

An infrastructure that includes both IBM MQ and service integration buses. This might be the result of a merger, or because the message traffic tends to be from WAS to WAS, or from IBM MQ to IBM MQ, but not typically between WAS and IBM MQ.
Deploy a WAS (JMS) messaging application to exchange messages with an application that uses an IBM MQ queue or topic.

If our business environment does not clearly indicate that we should use just one messaging provider, use a mixture of the two and choose the most appropriate provider for each application, based upon the destination types that the application uses.
The application might need to exchange messages with existing partner applications or services that use one or more known destinations of known type. Alternatively, the partner applications or services might not yet be deployed and the choice of destination type might still be open, in which case the solution architect needs to decide how best to connect the applications or services together.

If the application uses multiple destinations, there are four possible outcomes:

The application uses only bus destinations.
The application uses only IBM MQ destinations.
The application uses a mixture of bus and IBM MQ destinations.
The destination types are not yet known.

If there is no clear business or technical reason why the application uses IBM MQ destinations rather than bus destinations, and the partner application is also a WAS JMS application, consider migrating the existing destinations to service integration so that the application uses only bus destinations.
If the application uses only bus destinations, configure the application and its JMS resources to use the default messaging provider.
If the application uses only IBM MQ destinations (queues or topics), use the following checklist to determine which provider solution to use.

Question: MQP DMP interop, bus member DMP interop, foreign bus
Is performance critical?
(If so, use IBM MQ directly, rather than perform message conversion.)
*
Does the application have to send or receive large messages (that is, messages > 500k.)? *
Is location transparency desirable for simplifying programming and deployment of applications? * *
Does the application have to consume from an IBM MQ queue, the configuration of which is fixed?
(That is, the queue cannot be moved to service integration and we do not want to deploy a push-style IBM MQ application to send messages to a bus destination.)
* *
Is the partner application a JMS application that will run outside WAS, as a bus or IBM MQ client?
(Do not mix service integration and IBM MQ unless we have to do so; a pure IBM MQ or service integration solution is simpler and avoids the cost of converting messages between service integration and IBM MQ formats.)
*
Is the partner application a non-JMS (non-WAS) application?
(Wherever possible choose a pure IBM MQ or service integration solution. Use the MQI IBM MQ client, or the XMS IBM MQ client, or the XMS bus client depending on your API preference.)
*
Do you prefer traffic passing between the IBM MQ network and WAS applications to be funneled into a single long-running connection? *
Do we want to use the high availability features of WAS? *
Is XA two-phase commit (2PC) needed between the application and an IBM MQ queue-sharing group? * See ¹ * See ²
Is XA two-phase commit (2PC) needed between the application and an IBM MQ cluster? *
Are you using the WebSphere Enterprise Service Bus to mediate messages from, or deliver them to, an IBM MQ queue?
(For example, using WebSphere Business Integration adapters, or connecting to a service provider such as CICS .)
*
Does the application have to consume from an IBM MQ queue, the configuration of which is fixed?
(that is, the queue cannot be moved to service integration and we don't want to deploy a push-style IBM MQ application to send messages to a bus destination.)
* *

¹ Provided that IBM MQ v7.0.1 is used.
² XA two-phase commit can be used with the IBM MQ link, but it only covers the sending of the message to the IBM MQ link. It does not cover the subsequent sending of the message from the IBM MQ link to an IBM MQ queue manager using store and forwards.

If the application uses a mixture of bus and IBM MQ destinations, for example consuming from service integration and sending to IBM MQ, then either of the default messaging provider interoperation models can support this using a single connection factory or activation specification. Use the following checklist to help we decide between a bus member and a foreign bus solution.

Question: DMP interop, bus member DMP interop, foreign bus
Does the application have to consume from an IBM MQ shared queue? *
Do you prefer traffic passing between the IBM MQ network and WAS applications to be funneled into a single long-running connection? *
Do we need distributed IBM MQ in versions earlier than WAS v7 and IBM MQ v7? *
Do we want store and forward capabilities to allow the application to continue to send messages when the IBM MQ queue manager is unavailable? *
Do you prefer not to configure server connection channels?
(This is because they open a port, which might be seen as a security risk.)
* See ¹
Do you prefer to define a server connection channel, rather than a pair of sender and receiver channels? *
Do we only want to use bindings connections? *

¹ This is only applicable to send messages from IBM MQ to the service integration bus via the IBM MQ link, although we do need to open a port to the application server. Sending messages from the service integration bus to IBM MQ via the IBM MQ link requires a port to be opened to the queue manager through your firewall.

If the destination types are not yet known, decide the relative priorities of the known concerns then use the following checklist to assess how well each of them is addressed by the possible provider solutions.
The underlying choice is what type of destinations this application should use. The destination types are not yet fixed, so any of the four solutions is possible, but as a general rule we should aim for solution "DMP" or "MQP", because a pure IBM MQ or service integration solution is simpler and avoids the cost of converting messages between service integration and IBM MQ formats.

Question: DMP MQP DMP interop, bus member DMP interop, foreign bus
Do we have an existing base of strong skills in managing IBM MQ? * * *
Do we want management of all messaging to be handled by the IBM MQ team? *
Do we have administrators skilled in WAS but not in IBM MQ? *
Do we want a messaging product with a large installed base (including references) and a wide choice of ISV tools? *
Are you reluctant to buy a separately licensed product in addition to WAS? *
Are you reluctant to install and manage a separate product in addition to WAS? *
Are we already using IBM Integration Bus, known in earlier releases as WebSphere Message Broker?
(If so, we need IBM MQ anyway).
* * *
Does the application need to send or receive large messages (that is, messages > 500k.)? *
Is location transparency desirable for simplifying programming and deployment of applications? * * *
Do the throughput requirements need multiple parallel channels or routes? * * *
Is the partner application a JMS application that will also run in WAS?
(Service integration runs in the WAS application server. On distributed platforms that means it is in-process. (ZOS) On the z/OS platform it is in another region. Therefore using the default messaging provider gives a possible performance advantage on distributed platforms, but not on the z/OS platform. )
*
Is the partner application a JMS application that will run outside WAS, as a bus or IBM MQ client?
(Do not mix service integration and IBM MQ unless we have to do so; a pure IBM MQ or service integration solution is simpler and avoids the cost of converting messages between service integration and IBM MQ formats.)
* *
Is the partner application a non-JMS (non-WAS) application?
(Wherever possible choose a pure IBM MQ or service integration solution. Use the MQI IBM MQ client, or the XMS IBM MQ client, or the XMS bus client depending on your API preference.)
* *
Is maintenance of strict message order important? *
Does the application require the flexibility and convenience of an IBM MQ cluster?
(IBM MQ clustering makes administration simpler and provides selective parallelism of clustered queues. That is, instances of a clustered queue can be created on any (but not necessarily all) queue managers in the IBM MQ cluster. Messages sent to the clustered queue can be addressed to a specific instance of the queue, or allowed to select an instance dynamically based on workload management statistics. WAS clustering provides some of this flexibility, but we cannot create partitions of a bus destination on a subset of the messaging engines in a cluster bus member.)
* * *
Does the application need the level of high availability provided by IBM MQ for z/OS shared queues? * * *
Do we want to use the high availability or scalability features of WAS clustering? * * *

Subtopics

Comparison of WAS and IBM MQ messaging

Related:

Introduction: Messaging resources
Interoperation with IBM MQ: Comparison of key features
IBM MQ messaging provider
Manage messaging with the default messaging provider
Comparison of WAS and IBM MQ messaging

Question:	MQP	DMP interop, bus member	DMP interop, foreign bus
Is performance critical? (If so, use IBM MQ directly, rather than perform message conversion.)	*
Does the application have to send or receive large messages (that is, messages > 500k.)?	*
Is location transparency desirable for simplifying programming and deployment of applications?		*	*
Does the application have to consume from an IBM MQ queue, the configuration of which is fixed? (That is, the queue cannot be moved to service integration and we do not want to deploy a push-style IBM MQ application to send messages to a bus destination.)	*	*
Is the partner application a JMS application that will run outside WAS, as a bus or IBM MQ client? (Do not mix service integration and IBM MQ unless we have to do so; a pure IBM MQ or service integration solution is simpler and avoids the cost of converting messages between service integration and IBM MQ formats.)	*
Is the partner application a non-JMS (non-WAS) application? (Wherever possible choose a pure IBM MQ or service integration solution. Use the MQI IBM MQ client, or the XMS IBM MQ client, or the XMS bus client depending on your API preference.)	*
Do you prefer traffic passing between the IBM MQ network and WAS applications to be funneled into a single long-running connection?			*
Do we want to use the high availability features of WAS?			*
Is XA two-phase commit (2PC) needed between the application and an IBM MQ queue-sharing group?	* See ¹	*	See ²
Is XA two-phase commit (2PC) needed between the application and an IBM MQ cluster?		*
Are you using the WebSphere Enterprise Service Bus to mediate messages from, or deliver them to, an IBM MQ queue? (For example, using WebSphere Business Integration adapters, or connecting to a service provider such as CICS .)	*
Does the application have to consume from an IBM MQ queue, the configuration of which is fixed? (that is, the queue cannot be moved to service integration and we don't want to deploy a push-style IBM MQ application to send messages to a bus destination.)	*	*

Question:	DMP interop, bus member	DMP interop, foreign bus
Does the application have to consume from an IBM MQ shared queue?	*
Do you prefer traffic passing between the IBM MQ network and WAS applications to be funneled into a single long-running connection?		*
Do we need distributed IBM MQ in versions earlier than WAS v7 and IBM MQ v7?		*
Do we want store and forward capabilities to allow the application to continue to send messages when the IBM MQ queue manager is unavailable?		*
Do you prefer not to configure server connection channels? (This is because they open a port, which might be seen as a security risk.)		* See ¹
Do you prefer to define a server connection channel, rather than a pair of sender and receiver channels?	*
Do we only want to use bindings connections?	*

Question:	DMP	MQP	DMP interop, bus member	DMP interop, foreign bus
Do we have an existing base of strong skills in managing IBM MQ?		*	*	*
Do we want management of all messaging to be handled by the IBM MQ team?		*
Do we have administrators skilled in WAS but not in IBM MQ?	*
Do we want a messaging product with a large installed base (including references) and a wide choice of ISV tools?		*
Are you reluctant to buy a separately licensed product in addition to WAS?	*
Are you reluctant to install and manage a separate product in addition to WAS?	*
Are we already using IBM Integration Bus, known in earlier releases as WebSphere Message Broker? (If so, we need IBM MQ anyway).		*	*	*
Does the application need to send or receive large messages (that is, messages > 500k.)?		*
Is location transparency desirable for simplifying programming and deployment of applications?	*		*	*
Do the throughput requirements need multiple parallel channels or routes?		*	*	*
Is the partner application a JMS application that will also run in WAS? (Service integration runs in the WAS application server. On distributed platforms that means it is in-process. (ZOS) On the z/OS platform it is in another region. Therefore using the default messaging provider gives a possible performance advantage on distributed platforms, but not on the z/OS platform. )	*
Is the partner application a JMS application that will run outside WAS, as a bus or IBM MQ client? (Do not mix service integration and IBM MQ unless we have to do so; a pure IBM MQ or service integration solution is simpler and avoids the cost of converting messages between service integration and IBM MQ formats.)	*	*
Is the partner application a non-JMS (non-WAS) application? (Wherever possible choose a pure IBM MQ or service integration solution. Use the MQI IBM MQ client, or the XMS IBM MQ client, or the XMS bus client depending on your API preference.)	*	*
Is maintenance of strict message order important?	*
Does the application require the flexibility and convenience of an IBM MQ cluster? (IBM MQ clustering makes administration simpler and provides selective parallelism of clustered queues. That is, instances of a clustered queue can be created on any (but not necessarily all) queue managers in the IBM MQ cluster. Messages sent to the clustered queue can be addressed to a specific instance of the queue, or allowed to select an instance dynamically based on workload management statistics. WAS clustering provides some of this flexibility, but we cannot create partitions of a bus destination on a subset of the messaging engines in a cluster bus member.)		*	*	*
Does the application need the level of high availability provided by IBM MQ for z/OS shared queues?		*	*	*
Do we want to use the high availability or scalability features of WAS clustering?	*		*	*