[ODE-956] Asynchrony with Axis2-Nonblocking API

• Type: New Feature
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Axis2 Integration
• Labels: patch
• Assignee: Unassigned
• Reporter: Sathwik
• Created: 07/Mar/12 12:09
• Updated: 30/Oct/12 05:21

Description

To implement Axis2's non-blocking API to make a request/response service call asynchronously.

Related article:
http://www.ibm.com/developerworks/webservices/library/ws-axis2/index.html?ca=drs-
http://ws.apache.org/axis2/1_1/dii.html

This is really useful when we need to call an external/public service that takes a long time to respond, and that we have no authority to modify it, and we do not want to manage it with timeout parameters.

Here is what is needed:

1) Understanding of the WS-Addressing WSDL Binding: http://www.w3.org/TR/ws-addr-wsdl/
2) the Axis2 WS-Addressing-Module needs to be engaged. Until now it is disabled in all ODE deployments.
3) for testing, a small axis2 java client should be used, i.e. to invoke the hello world example (with setUseSeparateListener(true)).
4) a SOAP Monitor is needed to monitor SOAP messages and headers.

Then some experiments need to be performed. Here is what should happen:
1. The client sends the request to ODE.
2. ODE consumes the message and the transport ACKs the reception (HTTP 202 Accepted in the HTTP case)
3. ODE creates a new instance, does hello world and creates the response. The response is stored in the same MEX, since we're in a sync request-response operation.
4. Axis2 will open a new (anonymous) channel to the client and sends the message. Callback EPR has been transmitted via WS-Adressing header in the request.

When I tried that last time, the problem was, it actually worked fine, besides the fact that the request channel has not been closed and resulted in a timeout. Now I know that this can be fixed by adding a messageCtx.setProperty(DO_ASYNC, Boolean.TRUE); in the message receiver. This however should only be done in case this WS-Adressing-Binding should be used. Perhaps ODE could inspect the WSDL for occurrence of <wsaw:UsingAddressing/> and <wsaw:Anonymous> to determine whether a sync or async interaction should be used (I'd need to reread the spec to get sure).