{"id":398,"date":"2004-06-14T07:54:00","date_gmt":"2004-06-14T11:54:00","guid":{"rendered":"http:\/\/www.markbaker.ca\/wp\/?p=401"},"modified":"2004-06-14T07:54:00","modified_gmt":"2004-06-14T11:54:00","slug":"dave-orchard-on-protocol-evolvability","status":"publish","type":"post","link":"http:\/\/www.markbaker.ca\/blog\/2004\/06\/dave-orchard-on-protocol-evolvability\/","title":{"rendered":"Dave Orchard on protocol evolvability"},"content":{"rendered":"<p>A <a href=\"http:\/\/www.pacificspirit.com\/blog\/2004\/06\/14\/protocol_extensibility_and_versioning\">good post<\/a>\nby David on the relationship between data\nformat and protocol extensibility and evolvability.  I&#8217;m not sure I\ntotally agree with his conclusion &#8211; that &#8220;protocol designers [&#8230;] shouldn&#8217;t\nhave high hopes that they can regularly provide for compatible protocol\nevolution&#8221; &#8211; but the bulk of it makes sense.  I also think he&#8217;s approaching\nit from too theoretical a POV, since there are practical considerations that\nchange the dynamics he&#8217;s studying (as I\n<a href=\"http:\/\/www.pacificspirit.com\/blog\/2004\/05\/26\/substitution_rules_must_be_in_v10\">mentioned<\/a>\nto him).<\/p>\n\n<p>However, he finishes with this whopper;<\/p>\n\n<blockquote>\nAs an afterward, it may be worth pursuing trying to solve problems of protocol evolution by examining whether the use of a constrained protocol, ie HTTP, provides any greater evolvability for protocols\n<\/blockquote>\n\n<p>That kinda came out of left field, no?  I don&#8217;t see how that follows\nfrom what he wrote.  I agree, of course,\nbut just because a constrained interface provides\nself-descriptive messaging, and self-descriptive messaging provides better\nevolvability characteristics than the alternative, since the semantics of\nthe message are unambiguous.  This is in constrast to an SOA style\nmessage, where the most important semantic &#8211; the operation &#8211; is actually\n<a href=\"http:\/\/www.markbaker.ca\/2002\/09\/Blog\/2004\/03\/09\/#2004-03-operation\">purposefully removed<\/a>\nfrom the message.<\/p>\n\n<p>I&#8217;m looking forward to his next post, which I anticipate to have a\ntitle something like &#8220;Oh my, you mean HTTP and RDF are what I&#8217;ve been\nlooking for all along?!&#8221;. 8-)<\/p>","protected":false},"excerpt":{"rendered":"A good post by David on the relationship between data format and protocol extensibility and evolvability. I&#8217;m not sure I totally agree with his conclusion &#8211; that &#8220;protocol designers [&#8230;] shouldn&#8217;t have high hopes that they can regularly provide for compatible protocol evolution&#8221; &#8211; but the bulk of it makes sense. I also think he&#8217;s [&hellip;]","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-398","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/posts\/398","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/comments?post=398"}],"version-history":[{"count":0,"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/posts\/398\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/media?parent=398"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/categories?post=398"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/tags?post=398"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}