On Thu, May 29, 2008 at 11:41 AM, Mike Edwards < [EMAIL PROTECTED]> wrote:
> Folks, > > I've run into problems with the SCA BPEL implementation and the way it > interacts with the ODE engine - and I need help from some ODE experts, > please. > > OK, the SCA code is using the ODE engine in an embedded mode - and the > Tuscany code is trying to supply all the information and interfaces for each > BPEL process to the ODE Engine - and in particular it aims to bypass the ODE > database store so far as the BPEL process and its configuration are > concerned. > > So - Tuscany now has its own version of the ProcessConfImpl (I sent a > version of this out in a previous email). One thing I discovered is that it > is necessary for the Tuscany ProcessConfImpl to return "true" to the > isTransient() method. Otherwise, the ODE engine seems to try to find > information about the process in the database with nasty consequences > (failed transactions). > Normally that shouldn't be a problem. Transient tells ODE to execute the process in memory but that only applies to short living processes, for most scenarios you'll want to have persistent executions. So we should try to see why these transactions fail. > > HOWEVER, this has a side effect that is both curious and problematic. > > Using the ODE ProcessConfImpl (and by implication the database store for > the process itself), for a trivial "Hello World" BPEL process, when the > "hello" operation is invoked on the BPEL process, the ODE engine returns the > result message as a "DeferredElementNSImpl" class with the name "TestPart" - > which on inspection contains a child element "message" containing the > expected "Hello World" string. > (I attach the relevant part of the WSDL at the bottom) > > > When we switch to using the Tuscany ProcessConfImpl - with its "transient" > setting, when we invoke the same process, we get back a different type of > object - an "ElementImpl" named "TestPart". This contains an ElementNSImpl > object named "hello" containing a TextImpl child holding "Hello World". This > structural layout is clearly different to the previous case - and is wrong - > it isn't what is expected. > > Can anyone explain the difference in the two cases? Any assistance > gratefully received. > I don't see what could create this difference. The deferred element vs. normal element is nothing to worry about, it's just that the structure has already been traversed in one case because of the storage different, but the content itself should be identical. Usually the switch from transient to persistent doesn't bring that kind of differences but there's nothing I can think of off the top of my head that could create this behavior. The structural difference kind of reminds the difference between rpc and document style part wrappers but that shouldn't show here. So I'd like to reproduce this and see what's going wrong. Is all your code committed? Which test case are you using? Thanks, Matthieu > > Is it perhaps due to differences in the compilation of the process? Or is > the process treated in some very different way when it is transient? > > > > Yours, Mike Edwards. > ----------------------------------------- > Relevant WSDL sections: > > <wsdl:types> > <schema elementFormDefault="qualified" > targetNamespace=" > http://tuscany.apache.org/implementation/bpel/example/helloworld.wsdl"; > xmlns="http://www.w3.org/2001/XMLSchema";> > > <element name="hello"> > <complexType> > <sequence> > <element name="message" type="xsd:string"/> > </sequence> > </complexType> > </element> > </schema> > </wsdl:types> > > <wsdl:message name="HelloMessage"> > <wsdl:part element="tns:hello" name="TestPart"/> > </wsdl:message> > > <wsdl:portType name="HelloPortType"> > <wsdl:operation name="hello"> > <wsdl:input message="tns:HelloMessage" name="TestIn"/> > <wsdl:output message="tns:HelloMessage" name="TestOut"/> > </wsdl:operation> > </wsdl:portType> > > <plnk:partnerLinkType name="HelloPartnerLinkType"> > <plnk:role name="me" portType="tns:HelloPortType"/> > <plnk:role name="you" portType="tns:HelloPortType"/> > </plnk:partnerLinkType> > --------------------------------------- > Relevant BPEL section: > > <process name="HelloWorld" > targetNamespace=" > http://tuscany.apache.org/implementation/bpel/example/helloworld"; > xmlns:bpws="http://schemas.xmlsoap.org/ws/2004/03/business-process/"; > xmlns="http://schemas.xmlsoap.org/ws/2004/03/business-process/"; > xmlns:tns=" > http://tuscany.apache.org/implementation/bpel/example/helloworld"; > xmlns:xsd="http://www.w3.org/2001/XMLSchema"; > xmlns:test=" > http://tuscany.apache.org/implementation/bpel/example/helloworld.wsdl"; > queryLanguage="urn:oasis:names:tc:wsbpel:2.0:sublang:xpath2.0" > expressionLanguage="urn:oasis:names:tc:wsbpel:2.0:sublang:xpath2.0"> > > <import location="helloworld.wsdl" importType=" > http://schemas.xmlsoap.org/wsdl/"; > namespace=" > http://tuscany.apache.org/implementation/bpel/example/helloworld.wsdl"/> > > <partnerLinks> > <partnerLink name="helloPartnerLink" > partnerLinkType="test:HelloPartnerLinkType" myRole="me" /> > </partnerLinks> > > <variables> > <variable name="myVar" messageType="test:HelloMessage"/> > <variable name="tmpVar" type="xsd:string"/> > </variables> > > <sequence> > <receive > name="start" > partnerLink="helloPartnerLink" > portType="test:HelloPortType" > operation="hello" > variable="myVar" > createInstance="yes"/> > > <assign name="assign1"> > <copy> > <from variable="myVar" part="TestPart"/> > <to variable="tmpVar"/> > </copy> > <copy> > <from>concat($tmpVar,' World')</from> > <to variable="myVar" part="TestPart"/> > </copy> > </assign> > <reply name="end" > partnerLink="helloPartnerLink" > portType="test:HelloPortType" > operation="hello" > variable="myVar"/> > </sequence> > </process> >
