Chapter 6 Using Reliable Messaging
This chapter explains how to configure reliable messaging in web service
providers and clients.
This chapter covers the following topics:
Reliable Messaging Options
Table 6–1 describes the
reliable messaging configuration options.
Table 6–1 Endpoint Reliable Messaging Configuration
Options
|
Option
|
Description
|
|
Reliable Messaging
|
Specifies whether reliable messaging is enabled.
|
|
Ordered Delivery
|
Specifies whether the Reliable Messaging protocol ensures that the application
messages for a given message sequence are delivered to the endpoint application
in the order indicated by the message numbers.
This option increases the time to process
application message sequences and may result in the degradation of web service
performance. Therefore, you should not enable this option unless ordered delivery
is required by the web service.
|
|
Flow Control
|
Specifies whether the Flow Control feature is enabled. When enabled,
this option works in conjunction with the Max Buffer Size setting to determine
the maximum number of messages for sequence that can be stored at the endpoint
awaiting delivery to the application. Messages may have to be withheld from
the application if ordered delivery is required and some of their predecessors
have not arrived. If the number of stored messages reaches the threshold specified
in the Max Buffer Size setting, incoming messages belonging to the sequence
are ignored.
|
|
Max Buffer Size
|
If Flow control is enabled, specifies the number of messages that will
be buffered for a message sequence. The default setting is 32. For more information,
see the description of the Flow Control option.
|
|
Inactivity Timeout
|
Specifies the time interval beyond which either source or destination
may terminate any message sequence due to inactivity. The default setting
is 600,000 milliseconds (10 minutes). A web service endpoint will always terminate
a sequence whose inactivity timeout has expired. To keep the sequence active,
an inactive client will always send a stand- alone message with an AckRequested header to act as a heartbeat as the end of the Inactivity timeout
interval approaches.
|
Creating Web Service Providers and Clients that use
Reliable Messaging
Examples and detailed instructions on how to create web service providers
and clients that use reliable messaging are provided in the following chapters:
Using Secure Conversation With Reliable Messaging
If Secure Conversation is enabled for the web service endpoint,
the web service acquires a Security Context Token (SCT) for each application
message sequence, that is, each message sequence is assigned a different SCT.
The web service then uses that token to sign all messages exchanged for that
message sequence between the source and destination for the life of the sequence.
Hence, there are two benefits in using Secure Conversation with Reliable Messaging:
-
The sequence messages are secure while in transit between
the source and destination endpoints.
-
If there are different users accessing data at the source
and destination endpoints, the SCT prevents users from seeing someone else’s
data.
Note –
Secure Conversation is a WS-Security option, not a reliable messaging
option. If Secure Conversation is enabled on the web service endpoint, Reliable
Messaging uses Security Context Tokens.
For more information on how to use Secure Conversation, see Chapter 7, Using WSIT Security.