[no subject]

I do not share your assessment that Web services in general encourage
patterns which make deadlocks as likely as intra-process communication
does.

Kind Regards
DK



                                                                           
             "Yaron Y. Goland"                                             
             <ygoland@bea.com>                                             
                                                                        To 
             18.09.2004 00:01          Dieter Koenig1/Germany/IBM@IBMDE    
                                                                        cc 
                                       wsbpeltc                            
             Please respond to         <wsbpel@lists.oasis-open.org>       
                  ygoland                                          Subject 
                                       Re: [wsbpel] Issue - 52 - Proposal  
                                       For Vote                            
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           




The problem with this approach is that the copied EPR contains very
specific information about how communication is supposed to occur. For
example it could say things like "Send the message via SOAP over UDP
using WS-Security with a Kerberos Key and make sure to route it through
our high security firewall."

If a process was interested in testing its communication path then
copying the EPR and having the message be transmitted following the
EPR's instructions makes sense. But if a process really just wanted to
deliver a message to itself requiring that message to go through all the
hoops outlined in the EPR isn't appropriate.

This kind of misunderstanding is typical when one tries to implement a
feature as a side effect rather than declaratively. That is, the goal of
the code you give below is to allow a process to talk to itself but
rather than just stating that outright (which is what partnerIsSelf
does) the effect is achieved through a side effect of copying the EPR.
But that then introduces the complexities I describe above.

I also don't believe that IPC is anymore deadlock prone than business
process web services are. If we don't like IPC maybe we should also get
rid of Web Services? :)

                         Yaron

Dieter Koenig1 wrote:
>
>
>
>
> If one *really* chooses to model a process like this, it can be done
> already:
>    assign-copy from partnerLink "myself-inbound" (myRole) to
> "myself-outbound" (partnerRole)
>    invoke (use partnerLink "myself-outbound" and a correlation set to get
> the same instance)
>    receive (use partnerLink "myself-inbound" and a correlation set to get
> the same instance)
>
> In addition, imo, we should not introduce a dedicated construct which
> encourages intra-process-instance communication patterns that are asking
> for deadlocks.
>
> Kind Regards
> DK
>
>
>
>

>              "Yaron Y. Goland"

>              <ygoland@bea.com>

>
To
>              16.09.2004 03:05          wsbpeltc

>                                        <wsbpel@lists.oasis-open.org>

>
cc
>              Please respond to

>                   ygoland
Subject
>                                        [wsbpel] Issue - 52 - Proposal For

>                                        Vote

>

>

>

>

>

>

>
>
>
>
> In section 6.2, 7.2
> Change the partnerLink schema to:
>
> <partnerLinks>
>        <partnerLink name="ncname" partnerLinkType="qname"
>             myRole="ncname"? partnerRole="ncname"?
>             partnerIsSelf="Boolean"?>+
>        </partnerLink>
> </partnerLinks>
>
> Add the following text to the end of section 7.2:
>
> If the partnerIsSelf attribute is set to true then it indicates that the
> partnerRole points to the BPEL process instance in which the partnerLink
> is being used. The default value of the partnerIsSelf attribute is
> false. partnerIsSelf is used to support internal communication so that a
> BPEL process instance can send messages to itself. By specifying
> partnerIsSelf="true" the BPEL engine knows that it is to provide a
> binding for the partnerRole that points at the BPEL process instance.
>
> Add the following to the schema definition of tPartnerLink:
> <attribute name="partnerIsSelf" type="bpws:tBoolean" use="optional"
> default="no"/>
>
> To unsubscribe from this mailing list (and be removed from the roster of
> the OASIS TC), go to
>
http://www.oasis-open.org/apps/org/workgroup/wsbpel/members/leave_workgroup.php

>
> .
>
>
>
>
> To unsubscribe from this mailing list (and be removed from the roster of
> the OASIS TC), go to
>
http://www.oasis-open.org/apps/org/workgroup/wsbpel/members/leave_workgroup.php
.
>
>

To unsubscribe from this mailing list (and be removed from the roster of
the OASIS TC), go to
http://www.oasis-open.org/apps/org/workgroup/wsbpel/members/leave_workgroup.php
.