[kepler-dev] Re: [seek-dev] notes from workflow workshop

[Efrat Jaeger]

I was checking two of the workflow environments; Triana (Matthew Shields at
Crdiff University) and Taverna/MyGrid (European Bioinformatics Institute, IT
Innovation and the Human Genome Mapping Project Resource Center) and below
are my notes.

TRIANA is very similar to Ptolemy, both in the GUI part and in the src, but
it has a single computation semantic (reacting to signals).

It has a nice web services environment (although most of the their features
are already being added to Ptolemy/Kepler by Ilkay); a user can load any web
service from a specific repository (limited to a single repository) and the
interface creates a folder for each service added and adds its methods as
actors (the stub source of a web service is automatically generated by
WSDL2Java and is then compiled and loaded). The user can also retrieve a web
service outside the repository by providing a specific WSDL URL.

In order to discover web services input/output types, Triana has two WStypes
actors which automatically detect the type of its connected web service
method actor as it is being linked together (including sequence types) and
thus the user can add the input/output ports accordingly. With those
automatic type generators the input can be entered either as parameters
(manually) or as input port from a previous task (the output as well can be
either displayed or forwarded).

The interface also allows users to add new units/actors (similar to Chad's
new actor feature). It is possible to edit an actor's source code from
within the interface and then compile and run the new actor from within the
GUI (although I'm not sure of the stability of this feature and of how
recommended it is to allow the workflows users to edit the source code,
which can be saved automatically).


In TAVERNA everything is based on web services.

The taverna interface consists of several different view windows. The actors
are web services and are listed under the available services panel. Users
can load services and nested workflows from the web.

A model is described as an XScufl (XML Simple Conceptual Unified Flow
Language), which is similar to MOMLs. As in Ptolmey the interface plays a
role as a model (XScufl) editor, when a user adds an actor to the workflow
diagram it automatically generates the XScufl. A workflow is displayed on a
static graphical view and also on a tree view of the model which lists all
the components and allows the user to specify the connections between them
and define input and output characters (unlike Ptolemy the connection are
not linked in the graphical view, but in the tree view, the graphical view
is then automatically refreshed to show the links) .

In order to run the workflow there is a workflow input panel in which the
user can enter the input data, either a text or a file, and then the output
is displayed on a result window. The possible output types are the same as
provided by web services. It is viewed on the screen and can also be saved
to a file.

This environment consists a single computational model. The execution is
integrated via an encantor which specifies coordination constraints, but it
is very limited for now and is hardly used.


>
> >>>>> "CB" == Chad Berkley <berkley at nceas.ucsb.edu> writes:
> CB>
> CB> Hi,
> CB> Attached are a few notes that I took at the Workflow workshop in
> CB> Edinburgh.  These are the projects that I thought were interesting and
> CB> had something in common with one or more of our projects.  Some of
them
> CB> you have, no doubt, heard about already.  Feel free to email me with
> CB> any questions...maybe I'll be able to answer them.  All of the given
> CB> presentations with contact info can be seen here:
> CB> http://www.nesc.ac.uk/action/esi/contribution.cfm?Title=303
> CB>
> CB> chad
> CB>
> CB> narada brokering: naradabrokering.org
> CB>   stream oriented workflow: xgsp web service mcu arch.
> CB>
> CB>
> CB> chimera (argon):
> CB> virtual data language - describes data transformations (lineage
tracking)
> CB>   transformation - template of program invocation
> CB>   derivation - stores past and future (actual function call)
> CB>   invocation - how derivation was executed (log)
> CB>
> CB> MyGrid
> CB>   "Taverna" - build, edit and browse workflows
> CB>   import services
> CB>   integrated execution via Enactor
> CB>   Taverna Workflow Workbench - nice gui workflow editor
> CB>   supports control flow and data flow
> CB>   built in provenance control
> CB>   written in java
> CB>   taverna.sourceforge.net
> CB>   freefluo.sourceforge.net
> CB>
> CB> Geodise (engineering)
> CB>   allows the use of scripting within workflows
> CB>   map scripts onto workflow components
> CB>   workflow tool includes semantics and integrated ontologies
> CB>   using protege
> CB>   intelligent workflow monitoring and advice (rule based to case based
in real time)
> CB>
> CB> Choreology - OASIS WS BPEL TC
> CB>   BPEL - XML language for defining behaviour of a process
> CB>    provides web services
> CB>    uses web services
> CB>    everything is a web service (no external interactions)
> CB>
> CB> WS-CDL - Web Services Choreography Description Language (w3c)
> CB>   goal: declarative language that describes collaborations of web
services
> CB>     participants by defining their externally observable behavior as
part of an
> CB>     interorganizational transaction
> CB>   choreography - the observable public exchange of messages
> CB>   orchestration - private executable business process
> CB>   BPEL can be used to make choreography and orchestration work
together
> CB>   web servies participants interact and align their shared information
> CB>   set of interactions are combined to form a behavioral unit
(choreography)
> CB>
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