A bus destination is a virtual location within a service integration bus, to
which applications attach as producers, consumers, or both to exchange messages.
This topic provides a brief description of general destination concepts.
For more detailed descriptions of specific types of destinations, see Learning about bus destinations.
Bus destinations can
be either
"permanent" or
"temporary":
- A permanent destination is defined by an administrator for use by one
or more applications over an indeterminate period of time. Such destinations
remain until explicitly deleted by the administrator or by some administrative
command or script.
- A temporary destination is created and deleted by an application, or the
messaging provider, for use by that application during a session with a service integration bus. The destination is
assigned a unique name.
The following are the main types of destination:
- Queue
- A destination for point-to-point messaging.
- Topic space
- A destination for publish/subscribe messaging.
- Alias
- An alias destination makes a destination available by another name and, optionally, overrides the parameters of the destination. Applications
can use an alias destination to route messages to another destination in the
same bus or in another (foreign) bus.
- Foreign
- A foreign destination provides a mapping to a destination of the same
name on a different bus and enables applications on one bus to access directly
the destination on another bus. You can set its own destination
properties which will override the destination defaults.
You can configure queue, topic space, and alias destinations with one or
more mediations that refine how messages are handled by the destination.
You can configure queue, topic space, and alias destinations with routing
paths.
- The default forward routing path defines a sequential list of intermediary
destinations that messages must pass through to reach the target destination,
before consumers can retrieve the messages from that destination. Each intermediary
destination applies its mediations to the messages.
- The reply destination is the next destination to which reply messages
are sent.
Applications use API-specific artifacts like a JMS queue, which is associated
with a queue destination.
The mediations, default forward routing path, and reply destination are
all mechanisms that the administrator can use to modify the flow of messages
through the service integration bus. The administrator can create and modify these mechanisms without
the sending and receiving applications having to be aware or without any need
for the applications to be modified.