The
three different ways that you can send messages between WebSphere® Application Server and a IBM MQ network are compared at
a high level, showing the relative advantages and disadvantages of
each approach.
IBM MQ as an external messaging provider
The IBM MQ messaging provider does not use service integration. It provides JMS messaging access to IBM MQ from WebSphere Application Server.The IBM MQ messaging provider makes point-to-point messaging and publish/subscribe messaging available to WebSphere Application Server applications using the existing capabilities in the IBM MQ environment. WebSphere Application Server applications can interact with IBM MQ queues and topics to send, receive, publish, and subscribe to messages in the same way as any JMS application in the IBM MQ environment.
Using IBM MQ as an external messaging
provider requires more IBM MQ administration,
less WebSphere Application Server administration.
Table 1. Advantages and disadvantages of IBM MQ as an external messaging
provider. The first column of this table shows the advantages
of using IBM MQ as an external
messaging provider, and the second column shows the disadvantages
of using IBM MQ as an external
messaging provider.Advantages |
Disadvantages |
- You do not have to configure a service integration
bus or messaging
engines.
- You can connect directly to IBM MQ queue
managers.
- You manage a single JMS messaging provider rather
than two.
- You can connect to queue managers in client mode
or bindings mode.
- You can use point-to-point messaging and
publish/subscribe messaging.
|
- Interaction between WebSphere Application Server and IBM MQ is not seamless.
- You
cannot use service integration mediations for modifying messages,
for routing, or for logging.
|
A IBM MQ network as a foreign bus (using IBM MQ links)
A IBM MQ link provides a server to server channel connection between a service integration bus and a IBM MQ queue manager or queue-sharing group, which acts as the gateway to the IBM MQ network.When you use a IBM MQ link, the messaging bus is seen by the IBM MQ network as a virtual queue manager, and the IBM MQ network is seen by service integration as a foreign bus. A IBM MQ link enables WebSphere Application Server applications to send point-to-point messages to IBM MQ queues (defined as destinations in the service integration bus), and allows IBM MQ applications to send point-to-point messages to destinations in the service integration bus (defined as remote queues in IBM MQ). You can also set up a publish/subscribe bridge so that WebSphere Application Server applications can subscribe to messages published by IBM MQ applications, and IBM MQ applications can subscribe to messages published by WebSphere Application Server applications. The link ensures that messages are converted between the formats used by WebSphere Application Server and those used by IBM MQ.
Using
a IBM MQ network as a foreign
bus (using IBM MQ links) requires
more WebSphere Application Server administration,
less IBM MQ administration.
Table 2. Advantages and disadvantages of a IBM MQ network as a foreign bus
(using IBM MQ links). The first column of this table shows the advantages of using
a IBM MQ network as a foreign
bus (using IBM MQ links), and
the second column shows the disadvantages of using a IBM MQ network as a foreign bus
(using IBM MQ links).Advantages |
Disadvantages |
- A IBM MQ client facility
is not required on the gateway IBM MQ queue
manager.
- Each end of the link appears in natural form to the
other; IBM MQ appears to service
integration
to be a (foreign) bus, service integration appears to IBM MQ to be a (virtual) queue
manager.
- Better performance over the link is possible when
compared with IBM MQ servers
or direct connection
to IBM MQ as an external JMS
messaging provider.
- A managed connection from one node to
another is created, but
not from every application server in the cell.
- You do not
have to define individual IBM MQ queues
to the service integration
bus.
- Good security support is provided. For example, you can
control
which users are allowed to put messages onto queues.
- WebSphere Application Server and IBM MQ can exist on separate hosts.
- Interaction between WebSphere Application Server and IBM MQ is seamless.
- You
can configure a publish/subscribe bridge, through which WebSphere Application Server applications can
subscribe to messages published by IBM MQ applications, and IBM MQ applications can subscribe
to messages published by WebSphere Application Server applications.
|
- You must configure a service
integration bus and messaging engines.
- You cannot connect
to queue managers in bindings mode.
- Optimum load balancing
is less easy to achieve because messages
have to be "pushed" from either end of the link.
- You
cannot use service integration mediations for modifying messages,
routing, or logging.
|
A IBM MQ server (a queue manager or queue-sharing group)
as a bus member
A IBM MQ server provides a direct client connection between a service integration bus and queues on a IBM MQ queue manager or (for IBM MQ for z/OS®) queue-sharing group. For interoperation with WebSphere Application Server Version 7 or later, the version of WebSphere MQ must be WebSphere MQ for z/OS Version 6 or later, or WebSphere MQ (distributed platforms) Version 7 or later. A IBM MQ server supports the high availability and optimum load-balancing characteristics provided by a IBM MQ for z/OS network. A IBM MQ server defines the connection and quality of service properties used for the connection, and also ensures that messages are converted between the formats used by WebSphere Application Server and those used by IBM MQ. A IBM MQ server only represents queues for point-to-point messaging; it does not represent topics for publish/subscribe messaging.
Using
a IBM MQ server (a queue manager
or queue-sharing group) as a bus member requires more WebSphere Application Server administration,
less IBM MQ administration.
Table 3. Advantages and disadvantages of a IBM MQ server (a queue manager
or queue-sharing group) as a bus member. The first column
of this table shows the advantages of using a IBM MQ server (a queue manager
or queue-sharing group) as a bus member, and the second column shows
the disadvantages of using a IBM MQ server
(a queue manager or queue-sharing group) as a bus member.Advantages |
Disadvantages |
- WebSphere Application Server and IBM MQ can exist on separate hosts.
- Each end of the connection appears in natural form to the other; IBM MQ queue manager appears to
service integration to be a foreign bus, service integration appears
to IBM MQ to be a client.
- Close integration of applications is possible; service integration
applications are able to consume messages directly from the IBM MQ network.
- You can
connect to queue managers in client mode or bindings mode.
- You
can use mediations for modifying messages, routing, or logging.
- Good
security support is provided. For example, you can control
which users are allowed to put messages onto queues.
- You can
get messages from IBM MQ queues
(GET).
- Interaction between WebSphere Application Server and IBM MQ is seamless.
- Queues
on the IBM MQ network
are automatically discovered.
|
- You must configure a service integration bus and messaging engines.
- The queue managers and queue-sharing groups must be accessible
from all the messaging engines in the bus.
- You cannot use
the IBM MQ server
for publish/subscribe messaging with IBM MQ.
- IBM MQ for z/OS Version 6 or later,
or IBM MQ (distributed platforms)
Version 7 or later, is a prerequisite.
- If you are using different
nodes with IBM MQ for z/OS, depending
on the number
of nodes and your version of IBM MQ for z/OS,
you might require the Client Attachment feature (CAF) on z/OS.
- You
must explicitly define all destinations.
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