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Re: soap call - fire and forget

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  • techrg99
    I have been trying to do something similar - in my case I want the end user (thru a GUI) to be able to cancel the SOAP call - or at least ignore what the call
    Message 1 of 9 , Jan 8, 2004
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      I have been trying to do something similar - in my case I want the end
      user (thru a GUI) to be able to cancel the SOAP call - or at least
      ignore what the call returns... I think the issue is that since
      SOAP::Lite is using LWP to perform the HTTP communication, the process
      waits until a return or timeout. Perhaps there is a way to configure
      this??? I am experiementing with Perl 5.8.2 and using a separate
      thread to make the SOAP call. I have also seen ways to spawn another
      process to make the call so the main process is not stuck waiting
      around - for Win32 there is a good example in the O'reilly Programming
      Perl/Tk Book that goes out and gets comics and displays them back in
      the TK UI - this does not use SOAP, but does use LWP and the concepts
      work the same...
    • Byrne Reese
      I apologize to spam the group with something vaguely commercial, but I feel this thread warrants it. Grand Central is a Web Services network (technically, we
      Message 2 of 9 , Jan 8, 2004
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        I apologize to spam the group with something vaguely commercial, but I
        feel this thread warrants it.

        Grand Central is a Web Services network (technically, we call ourselves a
        "Business Services Network" - but I am not going to mince words) - in any
        event, Grand Central offers the ability to turn any SOAP call into an
        asynchronous non-blocking one.

        Most SOAP calls are synchronous in nature: socket opens, request is sent,
        message is processes, response returned, socket closes. However, as this
        threads suggests, not all SOAP calls follow this pattern. Sometimes you
        just want to fire off a notification. Sometimes, the SOAP call is likely
        to take a long time and hanging up a thread, or socket for that long is
        impractical, sometimes you just want to fire and forget... Grand Central's
        asynchronous messaging protocol can be used with any service deployed on
        the network.

        In a very small way you can think of GC as a proxy. In an asynchronous
        scenario a message is posted to a service. The network accepts the
        messages, and immediately returns a tracking number (used for the response
        correlation later) to the sender. Mean while the message traverses the
        system and is delivered to the utlimate destination (in some cases the
        message is sent to multiple services when the service you are sending a
        message to invokes a business process - we all heard of SOAP
        intermediaries, Grand Central actually uses them!). When the response is
        returned, it is held by Grand Central, and the user then polls for it,
        much like you poll a POP3 mail server for email.

        Grand Central is free as long as your bandwidth is less than 25MB per
        month. And you have me as an excellent support resource. I have made sure
        there are lots of Perl/SOAP::Lite examples on the GC developer site. :)

        http://www.grandcentral.com/developers/

        > I have been trying to do something similar - in my case I want the end
        > user (thru a GUI) to be able to cancel the SOAP call - or at least
        > ignore what the call returns... I think the issue is that since
        > SOAP::Lite is using LWP to perform the HTTP communication, the process
        > waits until a return or timeout. Perhaps there is a way to configure
        > this??? I am experiementing with Perl 5.8.2 and using a separate
        > thread to make the SOAP call. I have also seen ways to spawn another
        > process to make the call so the main process is not stuck waiting
        > around - for Win32 there is a good example in the O'reilly Programming
        > Perl/Tk Book that goes out and gets comics and displays them back in
        > the TK UI - this does not use SOAP, but does use LWP and the concepts
        > work the same...
        >
        >
        >
        >
        >
        >
        >
        > Yahoo! Groups Links
        >
        > To visit your group on the web, go
        > to:http://groups.yahoo.com/group/soaplite/
        > To unsubscribe from this group, send an email
        > to:soaplite-unsubscribe@yahoogroups.com
        > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
        >
        >
        >
        >
        >
        >
        >


        ^byrne :/
      • Lenz Gschwendtner
        ... thanks for that but we are programming a time critical high volume service so working with grand central in this place is not the thing planned. i know
        Message 3 of 9 , Jan 9, 2004
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          Byrne Reese wrote:

          >Grand Central is free as long as your bandwidth is less than 25MB per
          >month. And you have me as an excellent support resource. I have made sure
          >there are lots of Perl/SOAP::Lite examples on the GC developer site. :)
          >
          >
          >

          thanks for that but we are programming a time critical high volume
          service so working with grand central in this place is not the thing
          planned. i know grand central already but in our situation in the moment
          there is no plan to use the services provided.

          thanks for the info, but it is more essential for us in the moment to
          know how to implement a "notification" in SOAP::Lite

          lenz

          --
          ~
          ~
          ~
          ~
          ".signature" [New] 4L, 8C [w]
        • Aaron Trevena
          ... It sounds like you need ebXML rather than plain SOAP. ebXML Messaging (usually) runs on top of SOAP with Attachments - it supports synchronous and
          Message 4 of 9 , Jan 9, 2004
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            On Fri, 9 Jan 2004, Lenz Gschwendtner wrote:
            > thanks for that but we are programming a time critical high volume
            > service so working with grand central in this place is not the thing
            > planned. i know grand central already but in our situation in the moment
            > there is no plan to use the services provided.
            >
            > thanks for the info, but it is more essential for us in the moment to
            > know how to implement a "notification" in SOAP::Lite

            It sounds like you need ebXML rather than plain SOAP.

            ebXML Messaging (usually) runs on top of SOAP with Attachments - it
            supports synchronous and asynchronous messaging, provides Reliability and
            lots of powerful features that allow it to replace EDI.

            It is a bit heavyweight, but if you are building an application that needs
            those kind of features then it is justified and unavoidable.

            as a side note (who on the list doesn't have something to plug?) :
            I am looking for other perl developers interested in ebXML, we (a company
            I won't name yet) have some perl modules / classes that implement enough
            ebXML to hold brief (and often broken) conversations with the Hermes
            (free) ebXML MSH (a free, compliant ebXML MSH implementation written in
            Java) and hope to collaborate with others on getting it working better,
            sooner.

            cheers,

            A.

            --
            Aaron J Trevena - Perl Hacker, Kung Fu Geek, Internet Consultant
            AutoDia --- Automatic UML and HTML Specifications from Perl, C++
            and Any Datasource with a Handler. http://droogs.org/autodia
          • Alasdair Allan
            ... Well Grand Central is (just?) a broker implementating of something called Contextual Web Services, the project I m currently working on also makes
            Message 5 of 9 , Jan 9, 2004
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              > thanks for the info, but it is more essential for us in the moment to
              > know how to implement a "notification" in SOAP::Lite

              Well Grand Central is (just?) a broker implementating of something called
              Contextual Web Services, the project I'm currently working on also makes
              extensive use of them.

              You should probably look at the WS-Coordination and WS-Transaction specs,
              to see how transaction contexts are use to establish the scope of a
              transaction within an operation is executed.

              Al.
            • Bill Hess
              Is SOAP::Lite capable of perform asynchronous messages by itself. I assume the default is synchronous? And is this because of the way LWP works? One thing I
              Message 6 of 9 , Jan 9, 2004
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                Is SOAP::Lite capable of perform asynchronous messages by itself. I
                assume the default is synchronous? And is this because of the way LWP
                works?

                One thing I notice in a system we have recently developed is that when
                using is over a LAN it works great, except for the synchronous
                interaction. But when I run the system over a corporate VPN the
                interaction is "choppy" - slower and not as consistent, but any
                transaction always seems to finish OK. Could this be a result of
                SOAP::Lite or do you think it is the VPN? I have used other commercial
                client/sever type programs on this same VPN and some work fine (same as
                being on the LAN) and others are "choppy" and some are downright
                unreliable and fail. Could this be a result of some of these systems
                are synchronous/asynchronous?



                Byrne Reese wrote:
                > I apologize to spam the group with something vaguely commercial, but I
                > feel this thread warrants it.
                >
                > Grand Central is a Web Services network (technically, we call ourselves a
                > "Business Services Network" - but I am not going to mince words) - in any
                > event, Grand Central offers the ability to turn any SOAP call into an
                > asynchronous non-blocking one.
                >
                > Most SOAP calls are synchronous in nature: socket opens, request is sent,
                > message is processes, response returned, socket closes. However, as this
                > threads suggests, not all SOAP calls follow this pattern. Sometimes you
                > just want to fire off a notification. Sometimes, the SOAP call is likely
                > to take a long time and hanging up a thread, or socket for that long is
                > impractical, sometimes you just want to fire and forget... Grand Central's
                > asynchronous messaging protocol can be used with any service deployed on
                > the network.
                >
                > In a very small way you can think of GC as a proxy. In an asynchronous
                > scenario a message is posted to a service. The network accepts the
                > messages, and immediately returns a tracking number (used for the response
                > correlation later) to the sender. Mean while the message traverses the
                > system and is delivered to the utlimate destination (in some cases the
                > message is sent to multiple services when the service you are sending a
                > message to invokes a business process - we all heard of SOAP
                > intermediaries, Grand Central actually uses them!). When the response is
                > returned, it is held by Grand Central, and the user then polls for it,
                > much like you poll a POP3 mail server for email.
                >
                > Grand Central is free as long as your bandwidth is less than 25MB per
                > month. And you have me as an excellent support resource. I have made sure
                > there are lots of Perl/SOAP::Lite examples on the GC developer site. :)
                >
                > http://www.grandcentral.com/developers/
                >
                >
                >>I have been trying to do something similar - in my case I want the end
                >>user (thru a GUI) to be able to cancel the SOAP call - or at least
                >>ignore what the call returns... I think the issue is that since
                >>SOAP::Lite is using LWP to perform the HTTP communication, the process
                >>waits until a return or timeout. Perhaps there is a way to configure
                >>this??? I am experiementing with Perl 5.8.2 and using a separate
                >>thread to make the SOAP call. I have also seen ways to spawn another
                >>process to make the call so the main process is not stuck waiting
                >>around - for Win32 there is a good example in the O'reilly Programming
                >>Perl/Tk Book that goes out and gets comics and displays them back in
                >>the TK UI - this does not use SOAP, but does use LWP and the concepts
                >>work the same...
                >>
                >>
                >>
                >>
                >>
                >>
                >>
                >>Yahoo! Groups Links
                >>
                >>To visit your group on the web, go
                >>to:http://groups.yahoo.com/group/soaplite/
                >>To unsubscribe from this group, send an email
                >>to:soaplite-unsubscribe@yahoogroups.com
                >>Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
                >>
                >>
                >>
                >>
                >>
                >>
                >>
                >
                >
                >
                > ^byrne :/
                >
              • Byrne Reese
                Ok, so the million dollar question is: Is SOAP::Lite capable of performing asynchronous messaging by itself? The answer is yes, but not natively. There are
                Message 7 of 9 , Jan 9, 2004
                • 0 Attachment
                  Ok, so the million dollar question is:

                  "Is SOAP::Lite capable of performing asynchronous messaging by itself?"

                  The answer is yes, but not natively. There are two forms of asynchronous
                  messaging that I have seen:

                  1) A sends message to B. A transmits to B a port/socket (that A opens) for
                  the response to be sent to. When B is done processing the message, they
                  post their response to the port A designated. This port is the means of
                  correlating the response with the initial request. (BEA does something
                  similar to this I believe, but they also use a Conversation ID for
                  correlation as well, and if I am not mistaken, .NET does something like
                  this as well.)

                  This is known as a callback style of asynchronous messaging.

                  2) A sends message to B. B returns to A a Correlation ID. B polls A for
                  response using Correlation ID. (Of course this is the scenario that Grand
                  Central implements through its network because it's implementation it
                  doesn't depend upon the endpoint to actually comprehend ANY asynchronous
                  protocol.)

                  This is known as poll-based style of asynchronous messaging.

                  Here is the problem with 1) both asynch implementations that I know of are
                  proprietary protocols. It therefore requires that the server and client
                  both understand how to exchange messages, and correlate in this manner.

                  If I wanted to implement something like this in SOAP::Lite, I would
                  suggest implementing a CGI that could process returned responses. The
                  client would have to be able to generate a unique ID and trasmit it along
                  with the URL the CGI listens on to the service being called. The service
                  would then have to persist and return the correlation id provided by the
                  client, and post the response to the CGI/port designated by A.

                  I have actually implemented something like this, but again - it is highly
                  proprietary and therefore not very portable.

                  Asynchronous messaging is a highly desired feature enhancement for
                  SOAP::Lite, but I am not sure which standard to turn to for a COMPLETE
                  answer to the problem. WS-Correlation is only part of the problem - what
                  is the HTTP protocol?

                  As you


                  > Is SOAP::Lite capable of perform asynchronous messages by itself. I
                  > assume the default is synchronous? And is this because of the way LWP
                  > works?
                  >
                  > One thing I notice in a system we have recently developed is that when
                  > using is over a LAN it works great, except for the synchronous
                  > interaction. But when I run the system over a corporate VPN the
                  > interaction is "choppy" - slower and not as consistent, but any
                  > transaction always seems to finish OK. Could this be a result of
                  > SOAP::Lite or do you think it is the VPN? I have used other commercial
                  > client/sever type programs on this same VPN and some work fine (same as
                  > being on the LAN) and others are "choppy" and some are downright
                  > unreliable and fail. Could this be a result of some of these systems
                  > are synchronous/asynchronous?
                  >
                  >
                  >
                  > Byrne Reese wrote:
                  >> I apologize to spam the group with something vaguely commercial, but I
                  >> feel this thread warrants it.
                  >>
                  >> Grand Central is a Web Services network (technically, we call ourselves
                  >> a
                  >> "Business Services Network" - but I am not going to mince words) - in
                  >> any
                  >> event, Grand Central offers the ability to turn any SOAP call into an
                  >> asynchronous non-blocking one.
                  >>
                  >> Most SOAP calls are synchronous in nature: socket opens, request is
                  >> sent,
                  >> message is processes, response returned, socket closes. However, as this
                  >> threads suggests, not all SOAP calls follow this pattern. Sometimes you
                  >> just want to fire off a notification. Sometimes, the SOAP call is likely
                  >> to take a long time and hanging up a thread, or socket for that long is
                  >> impractical, sometimes you just want to fire and forget... Grand
                  >> Central's
                  >> asynchronous messaging protocol can be used with any service deployed on
                  >> the network.
                  >>
                  >> In a very small way you can think of GC as a proxy. In an asynchronous
                  >> scenario a message is posted to a service. The network accepts the
                  >> messages, and immediately returns a tracking number (used for the
                  >> response
                  >> correlation later) to the sender. Mean while the message traverses the
                  >> system and is delivered to the utlimate destination (in some cases the
                  >> message is sent to multiple services when the service you are sending a
                  >> message to invokes a business process - we all heard of SOAP
                  >> intermediaries, Grand Central actually uses them!). When the response is
                  >> returned, it is held by Grand Central, and the user then polls for it,
                  >> much like you poll a POP3 mail server for email.
                  >>
                  >> Grand Central is free as long as your bandwidth is less than 25MB per
                  >> month. And you have me as an excellent support resource. I have made
                  >> sure
                  >> there are lots of Perl/SOAP::Lite examples on the GC developer site. :)
                  >>
                  >> http://www.grandcentral.com/developers/
                  >>
                  >>
                  >>>I have been trying to do something similar - in my case I want the end
                  >>>user (thru a GUI) to be able to cancel the SOAP call - or at least
                  >>>ignore what the call returns... I think the issue is that since
                  >>>SOAP::Lite is using LWP to perform the HTTP communication, the process
                  >>>waits until a return or timeout. Perhaps there is a way to configure
                  >>>this??? I am experiementing with Perl 5.8.2 and using a separate
                  >>>thread to make the SOAP call. I have also seen ways to spawn another
                  >>>process to make the call so the main process is not stuck waiting
                  >>>around - for Win32 there is a good example in the O'reilly Programming
                  >>>Perl/Tk Book that goes out and gets comics and displays them back in
                  >>>the TK UI - this does not use SOAP, but does use LWP and the concepts
                  >>>work the same...
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>Yahoo! Groups Links
                  >>>
                  >>>To visit your group on the web, go
                  >>>to:http://groups.yahoo.com/group/soaplite/
                  >>>To unsubscribe from this group, send an email
                  >>>to:soaplite-unsubscribe@yahoogroups.com
                  >>>Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>>
                  >>
                  >>
                  >>
                  >> ^byrne :/
                  >>
                  >
                  >


                  ^byrne :/
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