Re: Fw: invoke/receive/reply

["Antony Miguel" <antony.miguel@scapatech.com>]

Hi Michael,

Thanks for your response but I don't actually know what WMQ is.  I'm
implementing a BPEL engine and I'm asking about the general definition of
BPEL receive and reply activities.  What I want to know is, when a receive
like

<receive partnerLink="plinkASide" portType="ptype" operation="op"
variable="myvar" />

is specified in a BPEL program, and it is replied to using a BPEL <reply>
activity like

<reply partnerLink="plinkBSide" portType="ptype" operation="op"
variable="myreplyvar" />

is this equivalent to a WSDL "Notification" type of operation (as defined in
the WSDL specification - section 2.4) and if so, is a BPEL invoke with an
outputVariable but no inputVariable such as

<invoke partnerLink="plinkASide" portType="ptype" operation="op"
outputVariable="myvar" />

the same thing?

Antony Miguel
Scapa Technologies
antony.miguel@scapatech.com
+44 131 550 1766
----- Original Message -----
From: "Michael B Mccarthy" <mbmccarthy@us.ibm.com>
To: <Antony.Miguel@scapatech.com>
Cc: <wsbpel-comment@lists.oasis-open.org>
Sent: Wednesday, July 07, 2004 8:00 PM
Subject: Re: Fw: invoke/receive/reply


>
>
>
>
>  I believe you're asking about WMQ with the Request-Reply question.  The
> short answer is that they DO form a pair.  The slightly less short answer
> is this.  WMQ has a 364 byte control area before the data message.  Two of
> its fields are a 24-byte "Message ID" and a 24-byte "Correllation ID".
> When a message is sent the system generates a unique Message-ID.  The
> sender should also code a "Message Type" in the MSGTYPE (vs. a "Datagram",
> etc.)  The standard convention is for the receiver of the message to move
> the Message-ID field to the Correllation ID as before sending the reply
> back.  The original sender then does an MQGET with the Correllation ID
> coded and will only pick up the reply to the original request.  I don't
> know exactly how the pieces work in the other environments but this is
> probably the WMQ counterpart.
>
> Sincerely,
>
>
> Michael B. McCarthy
> IBM Software Group
> Business Integration Specialist SSR
> Office (781)334-3578
> mbmccarthy@us.ibm.com
>
>
>
>              "Antony Miguel"
>              <antony.miguel@sc
>              apatech.com>                                               To
>                                        <wsbpel-comment@lists.oasis-open.or
>              07/07/2004 12:16          g>
>              PM                                                         cc
>
>                                                                    Subject
>                                        Fw: invoke/receive/reply
>
>
>
>
>
>
>
>
>
>
> Is receive-reply equivalent to the WSDL "Notification" type of operation?
> If so, then does it mean the same thing to execute an invoke with no
> inputVariable and an outputVariable?
>
> e.g. is
>
>             <receive partnerLink="plink" portType="ptype" operation="op"
> variable="myvar" />
>
> equivalent to
>
>             <invoke partnerLink="plink" portType="ptype" operation="op"
> outputVariable="myvar" />
>
> thanks
>
> Antony
>
> ----- Original Message -----
> From: Antony Miguel
> To: wsbpel-comment@lists.oasis-open.org
> Sent: Tuesday, July 06, 2004 2:14 PM
> Subject: Re: invoke/receive/reply
>
> I should add to this question that an alternative I might expect would be
a
> <pick> - <reply> pair.
>
> Antony Miguel
> Scapa Technologies
> antony.miguel@scapatech.com
> +44 131 550 1766
>  ----- Original Message -----
>  From: Antony.Miguel@scapatech.com
>  To: wsbpel-comment@lists.oasis-open.org
>  Sent: Tuesday, July 06, 2004 12:32 PM
>  Subject: invoke/receive/reply
>
>  Hi,
>
>  Hopefully this is the right place to be asking this question.  If the
>  question is not appropriate or anyone knows of a better place to ask then
>  please let me know.
>
>  I recently saw an example BPEL program where there were two activities in
>  a <flow>, one doing a <receive>, and the other sending a message to it
>  using a <reply>.  I can't find the example again and I may have just
>  misinterpreted it but am I correct in thinking that in BPEL, a <receive>
>  always receives from an invoke (or from some externally bound incoming
>  message), and never from a <reply>?
>
>  My understanding is an invoke should always mean a receive-reply pair
>  somewhere.  Is this correct?
>
>  thanks
>
>  Antony Miguel
>  Scapa Technologies
>  antony.miguel@scapatech.com
>  +44 131 550 1766
>
>