Comments on: Web Services Versioning - Part 2 http://www.subbu.org/blog/2005/08/web-services-versioning-part-2 HTTP, REST and some Cycling Thu, 20 Nov 2008 09:07:17 +0000 http://wordpress.org/?v=2.7-beta3 hourly 1 By: Subbu Allamaraju http://www.subbu.org/blog/2005/08/web-services-versioning-part-2/comment-page-1#comment-67 Subbu Allamaraju Sat, 17 Sep 2005 18:42:10 +0000 http://wp.subbu.org/2005/08/web-services-versioning-part-2/#comment-67 <p>My answers:</p> <ol> <li>The goal is to not force existing clients to upgrade to use new ports. If a client wants to upgrade to use new ports, it will then have to conform to the new schema and semantics.</li> <li>Just for readability.</li> <li>You don't need to duplicate service implementations. Depending on the degree of changes, you can limit the changes to a few extra classes.</li> <li>Message transformation is possible, but it usually takes some work. The second approach via abstraction layer is simpler, and is practical.</li> <ol></ol></ol> My answers:

  1. The goal is to not force existing clients to upgrade to use new ports. If a client wants to upgrade to use new ports, it will then have to conform to the new schema and semantics.
  2. Just for readability.
  3. You don’t need to duplicate service implementations. Depending on the degree of changes, you can limit the changes to a few extra classes.
  4. Message transformation is possible, but it usually takes some work. The second approach via abstraction layer is simpler, and is practical.
    ]]>         By: Kumar Reddy TCS http://www.subbu.org/blog/2005/08/web-services-versioning-part-2/comment-page-1#comment-66 Kumar Reddy TCS Thu, 08 Sep 2005 06:59:40 +0000 http://wp.subbu.org/2005/08/web-services-versioning-part-2/#comment-66 Hi subbu,<br /> Web Services Versioning - Part 2 is an very outstanding article. This article really made me to think, about compatability issues if there is any versioning in web services as I was earlier not aware of all these. You are right, as you said earlier that "problem of versioning could test the motivation of even the most committed web services architect."<br /><br /> <strong>Also, there are few question from my side.</strong> <br /> 1. As per your wsdl versioning, Clients using the new version will therefore use new ports, and clients using the old version(s) will continue with old ports. But, what if there is a situation, where the client using the old webservices, need to access the new services or vice versa?. <br /><br /> 2. Why is that, you made the schemas in to small chunks and imported them to main schema file. I was just curious to know, whether this is because, you thought this for any performance issue, or this is for readability alone, or it is it your own programming style or practice for developing web services? <br /><br /> 3. In order to make the web services compatible, I believe we are creating all the code again, for even a small change in the schema. Suppose, think, if there is an addition of an attribute or an element. According to you, we need to write the whole new schema again, including the port types, messages, operations and bindings. Dont you think, this causes redundancy of code?. Is there any other ideal soulution to this problem or what ever you said is the best? <br /><br /> 4. And making web service implementations support versioning, you showed two methods.<br /> a.Message Transformation and Routing<br /> b.Common Data Abstraction Layer<br /> Do this models are really implementable. I mean, Did any one implemented this models. OR this is purely theoritical.<br /><br /><br /> Hope you will get back.<br /><br /><br /> Cheers Kumar Hi subbu,

    Web Services Versioning - Part 2 is an very outstanding article. This article really made me to think, about compatability issues if there is any versioning in web services as I was
    earlier not aware of all these. You are right, as you said earlier that “problem of versioning could test the motivation of even the most committed web services architect.”

    Also, there are few question from my side.

    1. As per your wsdl versioning, Clients using the new version will therefore use new ports, and
    clients using the old version(s) will continue with old ports. But, what if there is a situation, where the client using the old webservices, need to access the new services or vice versa?.

    2. Why is that, you made the schemas in to small chunks and imported them to main schema file. I
    was just curious to know, whether this is because, you thought this for any performance issue, or this is for readability alone, or it is it your own programming style or practice for developing web services?

    3. In order to make the web services compatible, I believe we are creating all the code again,
    for even a small change in the schema. Suppose, think, if there is an addition of an attribute or
    an element. According to you, we need to write the whole new schema again, including the port
    types, messages, operations and bindings. Dont you think, this causes redundancy of code?. Is
    there any other ideal soulution to this problem or what ever you said is the best?

    4. And making web service implementations support versioning, you showed two methods.
    a.Message Transformation and Routing
    b.Common Data Abstraction Layer

    Do this models are really implementable. I mean, Did any one implemented this models. OR
    this is purely theoritical.

    Hope you will get back.

    Cheers
    Kumar

    ]]>