Large message splitting and joining

Activator supports the splitting and joining of large AS4 messages.

Splitting and joining operates only if the AS4 message has attachments or MTOM optimized content.

How it works

• Activator sender:
• In message sender role, Activator splits large AS4 messages into multiple fragments, wrapping each fragment in a separate message with a MessageFragment header element. Activator sends multiple AS4 messages to the trading partner for a single submitted source AS4 message.
• Activator receiver:
• In message consumer role, Activator detects the presence of a MessageFragment header element in the inbound AS4 message. This indicates that the content of the fragment is part of a larger message. On receiving fragment message, Activator halts the processing until all related fragments are received. When all the fragmented messages are received, Activator re-assembles them by parsing the MessageFragment header and reconstructing the MIME envelope. Activator then continues to process the re-assembled MIME message.
• In the case of pulled AS4 split messages, each fragment is pulled individually. The pull request is authorized for fragments using the same parameters as for regular AS4 messages.

Receipt handling of split messages

To generate a receipt signal with non-repudiation for the reassembled message (since the reassembled message is not signed), Activator in receiving mode automatically computes a hash value for the payload parts. This differs from regular AS4 processing, where the non-repudiation receipt can be generated using the elements of the security header in the received signed user message.

Configure splitting

To set up AS4 message splitting and joining, complete the following tasks:

• Set the default fragment size in the Activator System Properties
• Set Collaboration Settings
• Enable spitting in an AS4 MMD

Set the default fragment size and join time-limit

1. Log into the Activator user interface as an administrator.
2. Manually enter the following URL in your browser: http://{localhost or machinename}:6080/ui/core/SystemProperties
3. The Systems properties page is displayed.
3. At the bottom of the page click Show default system properties.
4. Locate the following system properties in the list:
   • as4.fragmentSize – Maximum size of a AS4/ebXML fragment (in kilobytes)
   • as4.joinExpirationCheck.interval – Maximum time to wait for receiving/pulling AS4 fragments for re-joining (in minutes).
5. If you want to modify either of these values, click Add, enter a modified value and click Add again. Then click Save changes on the System properties page.

Set Collaboration Settings

To enable outbound AS4 splitting:

1. From the Trading configuration menu, select Change default collaboration settings.
2. The Collaboration defaults for sending messages page is displayed.
2. Click the AS4 tab.
3. In the AS4 Collaboration Settings section, select:
   • Split messages - Enables Activator to fragment outbound AS4 user messages.
   • MIME envelope compression – Optionally apply GZIP compression on the MIME envelope for outbound user messages, before splitting.
4. See Collaboration default settings / AS4 default settings.

Enable spitting in an AS4 MMD

Setting up the following metadata in an MMD, overrides the Splitting configuration in collaboration settings.

For AS4 pushes, include the following attributes (using preferred values for size and compression):

For outbound AS4 pull-queued messages, include the following attributes (using preferred values for size and MPC):

For additional details about metadata and MMD management, see AS4 metadata.

Related topics

• AS4
• AS4 messages
• AS4 metadata
• Message Partition Channels (MPC)
• AS4 user authentication
• Enable handling of empty SOAP Body messages
• Configure a one-way client pull
• AS4 use case: One-way push (MMD initiated)
• AS4 use case: One-way pull (MMD initiated)
• AS4 tasks