About understanding the pi' message processing

Question

Dear All:
   I wanna to know  the detailed step of  message  process  in PI,for example  :   message throught the adapter  message system  IS  , Anyone can helpe me,or give me some doucument.
thanks!
kevin  liang

Answer 1

hi,
Message flow from Adapter Engine to Integration Server
1.     For the message to be picked up by the communication channel, the channel should be associated with a sender agreement. Mere creation of a communication channel doesnu2019t ensure the message to be polled and picked up by the adapter. The message reaches the adapter in its native message format. As the communication in SAP XI happens in XI message format, a module inside the adapter converts the message in native format into XI message format.
2.     During this process, a message ID is generated for the message. To build the XI header (sender agreement details like the sender system, sender message interface and the interface namespace) the details are fetched by performing a CPA lookup(collaboration-partner-agreement are the configuration object details that have been created using the configuration time. The details are updated into the runtime cache when you activate the Configuration objects in Integration builder u2013Configuration time. This cache is referred to as CPA cache).
3.     This message is then sent to module processor for further processing. During the process of sending the message to module processor, the message u201CApplication attempting to send an XI message asynchronously using connection AFWu201D is logged.
4.     The module processor performs steps like structure conversion, communication channel specific conversions (that have been specified in the u201Cmodule tabu201D of the adapter channel). These conversion modules are executed in the same sequence as mention in the communication channel.
5.     After the successful execution of the conversion modules, the appropriate module (call SAP adapter module) of the module processor is called which will send this message for persistent storage. This message is put into the Send Queue of the messaging system for further processing. Messages like u201CMessage trying to put into the send Queueu201D and u201CMessage successfully put into the queueu201D are logged during this process. A confirmation message (success/ failure) is sent back to the sender application at this stage. This confirmation message is used by the channel to perform various steps like deleting the file that has a processing mode as delete.
6.     The message that has been put in the Send Queue has to be picked up and sent to the Integration Engine. The Adapter Engine and XI Integration server use XI Adapter for internal communication purposes. So the XI Adapter picks up message from the send queue and parses the XI message. In this process, the status of the message is set to DLNG and. Messages like u201CThe message was successfully retrieved from the send queue and message status set to DLNGu201Dare logged.
7.     The XI adapter performs a SLD look up (System landscape Directory) to find the Integration server with which the Adapter framework has register itself.
8.     On successful SLD look up, the message is sent via HTTP to the XI IS pipeline, using the pipeline URL (http://hostname:abap-httpport/sap/xi/engine?type=entry). . If this is successful, a message u201CThe message was successfully transmitted to endpoint http://hostname:8000/sap/xi/engine?type=entry using connection AFWu201D is logged and the message statues is set to DLVD means message has been successfully delivered to the endpoint( XI IS in this case)
<h5>see also pipeline steps that are executed in Integration Server</h5>
also see this
[http://help.sap.com/saphelp_nw04/helpdata/en/1b/89d24032f68231e10000000a1550b0/frameset.htm]