Configuring Splitting and Joining ebMS Messages
Message splitting and joining involves two related operations. During the Send operation of a large user message, the sending MSH splits the message into multiple fragments. Each fragment is wrapped in its own SOAP message with a MessageFragment header extension element and then sent to the receiving MSH in a separate thread from a thread pool. The thread pool properties (that is, the as4.throttling properties) can be configured for optimal performance. For more information, see
Configuring AS4 Configuration
Properties.
During the Receive operation, the presence of a MessageFragment header element indicates that the message content is part of a larger message. Once all the fragments have been received, they are reassembled and joined into a single message again.
The set of fragments that make up a user message belong to one group. Each group is assigned one of the following statuses:
Value | Description |
ACTIVE | One or more fragments of the group was received and there are still more fragments to come. |
COMPLETE | All fragments in the group were received. |
EXPIRED | A group fragment was received after the time set for the joinInterval parameter elapsed. |
REJECTED | There was a problem during processing of one of the fragments in the group. |
When a user message is split and then separate fragments are sent, the TPA parameters for security and reception awareness apply at the fragment level, not the source message level. That is, the message fragments are individually secured. In addition, message acknowledgments, retries, and duplicate detection apply at the fragment level.
Note:
Receipts cannot be generated for joined user messages.
Module for AS4 provides built-in services to manage fragment groups. For more information, see
Built-In Services.
To configure splitting and joining of ebMS messages
1. In My webMethods: Administration > Integration > B2B > Trading Partner Agreements > Trading Partner Agreement Details.
2. Select the TPA for which you want to configure splitting and joining.
3. In the TPA data panel, configure the splitting parameter as follows:
Parameter | Value |
enabled | Optional. Whether or not splitting is enabled. Specify one of the following:  true—Enabled. false—Disabled. This is the default. |
fragmentSize | The size of each fragment, in bytes. For example, if fragmentSize is defined as 1000 bytes and the message is 2050 bytes, the message is split into two fragments of 1000 bytes each, and one fragment of 50 bytes. If the message is 900 bytes, one fragment of 900 bytes is sent. |
joinInterval | The maximum time, in seconds, to expect and process additional fragments after the first fragment is received. |