Errors that can occur in writing workflows,

Incorrect WSFL

This can be checked using the verify (-v) option of the enactment engine. You get the error "Workflow specification was invalid with respect to XSD schema". If you submit the workflow, you may get more details of the error, for example the JDOMException and a line number.

A common mistake is a typo between the name of an element and its use: for example file_Activity and file_activity below

<activity name="file_Activity">
   <performedBy serviceProvider="file_test"/>
   <implement>
...[lines deleted]
   </implement>
</activity>

<dataLink source="describe_activity" target="file_activity">
...[lines deleted]
</dataLink>

Incorrect Input Template

On submitting the workflow you may get an error "The input document wasn't well formed".

A missing element is one possible cause. For example if

</data>

is omitted.

Incorrect or Unavailable WSDL file

If a workflow locator element refers to a WSDL file that is not available, then the workflow terminates with status FAILED.

The enactment engine log file includes an error "Unable to resolve imported document at [URL]", which identifies the problem file. For example

... Error.  At least one message in 'file_activity' given in the invocation specification isn't supported 
by 'http://localhost:8080/axis/services/TestFileService?wsdl' for activity 'file_activity'..  
Root cause: 
uk.ac.soton.itinnovation.mygrid.workflow.enactor.invocation.wsdl.WSDL
ParseException: Problem reading WSDL.  
Root cause: WSDLException:
 faultCode=OTHER_ERROR: Unable to resolve imported document
 at 'http://localhost:8080/axis/services/TestFileService?wsdl'.: This file was not found:
 file:http://localhost:8080/axis/services/TestFileService?wsdl:
 java.net.MalformedURLException: 
This file was not found:
 file:http://localhost:8080/axis/services/TestFileService?wsdl
 at com.ibm.wsdl.util.StringUtils.getURL(Unknown Source) ...

Incorrect portType

If the portType attribute within a WSFL activity declaration refers to a portType that is not in the located service's WSDL file then then the workflow terminates with status FAILED.

The enactment engine log file includes an error, "A suitable SOAP port ..." e.g.

A suitable SOAP port for invoking the 'describe_activity' wasn't found 
in the WSDL at: http://www.ebi.ac.uk/collab/mygrid/service4/soap/services/alignment::blastx_ncbi::derived?wsdl

Output or Provenance Service unavailable

If the workflow has logProvenance set to true, and the enactor is configured to call a provenance service, but that service is not available then the workflow terminates with status FAILED.

The standard out from the enactment engine will give an error referring to ProvanenceFinalise and the enactment engine log file will include an error such as

Axis error calling provenance web service to log *provenance*

If the workflow enactor is configures to call an output service, but that service is not available then the workflow terminates with status FAILED.

The standard out from the enactment engine will give an error referring to StoreOutput and the enactment engine log file will include an error such as

Axis error calling repository web service to log *output*

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-- MarkGreenwood - 26 Mar 2003 last revised 24 Apr 2003