Daniel Fisher aka "Lenny Bacon" joined the pack and is already having some fun.
Microsoft Watch highlights the recently surfaced HP memo that speculates that Microsoft would start enforcing its patent portfolio on Open Source. How likely is it? It is an interesting question, indeed. Here’s what I think:
The patent situation, especially on the middleware market, used to be very much like the cold war between the USSR and the USA in the last century. One side moves, everyone dies. My guess is that if Microsoft had gone out and dragged Sun to court over J2EE and Sun had countersued over .NET, things would have gotten really, really nasty. The very foundations of the J2EE stack are sitting right in the middle of a substantial Microsoft patent minefield covering what we know as MTS and COM+. The reverse doesn’t look much better. Now Sun and Microsoft made peace on that front and are even looking to negotiate a broad IP cross-licensing deal to end that sort of arms race. Cross-licensing of patents is quite common in this industry and in most other industries as well. So where does that leave the grassroots Open Source movement? Not in a good place, for sure.
If you do research and you pour millions or even billions into that research, there has to be some return on that investment. And there is a difference between academic research and research that yields commercial products. I am not saying that there is no close relationship between the two, but both are done with different goals. If you do research for commercial purposes, regardless of whether you do it in the automotive industry or in the pharmaceutical industry or even in the software industry, the results of your research deserve protection. At the same time, it is harmful to the society at-large, if everyone would keep all results of all research under wraps. So governments offer companies a deal: You disclose the results of your research and we grant you a limited-time monopoly to use that technology exclusively. If you decide to share the technology with other parties, you can be forced to allow third parties to license it on appropriate terms. And the German Patent law §11 (1) , for instance, explicitly states that patents do not cover noncommercial use of technology in a private environment.
Now, if states offer that sort of system, a company that is built almost only on intellectual property (like Sun, IBM, Oracle, Apple, Microsoft and so forth) must play with the system. The must file for patents. If they don’t, they end of with something like the Eolas mess in their hands and that is not pretty. Even if some of the patents seem absolutely ridiculous; if the patent lawyers at a large company figure out that a certain technology is not covered by an existing patent, they must go and protect it. Not necessarily to enforce it, but rather to avoid that someone else enforces it on them. And because a lot of these patents are indeed idiotic, such are rarely ever enforced and most often quite liberally licensed. Something similar is true for trademarks. Microsoft has no choice but to chase Lindows (now Linspire) or even poor “Mike Rowe Soft” because they must defend their trademarks, by law. If they don’t and let a case slip, they might lose them. It’s not about being nasty, it’s just following the rules that lawmakers have set.
Now, if someone starts cheating on the research front and consumes IP from that system but never contributes IP to the system, it does indeed change the ballgame. If you don’t have a patent portfolio that is interesting enough for someone else to enter a (possibly scoped) cross-licensing deal with you and you don’t license such patents for money but instead break the other parties’ rightfully (it’s the law!) acquired, time-limited monopolies on commercial use of the respective technologies and you do so for profit, then you are simply violating the rules of the law. That’s as simple as it is. So, if I held Sun’s or Microsoft’s patent portfolio, would I ask those who profit from commercialization of those patents for my share? I really might give it some serious consideration. I think companies like Red Hat make wonderful targets, because they are commercial entities that profit greatly from a lot of IP that they do not (as I suspect) have properly licensed for commercial exploitation. The interesting this is that my reading of the (German) patent law is that the non-profit Apache Foundation can actually use patented technology without being at risk, but a for-profit company cannot adopt their results without being liable to acquire a license. Even giving away “free” software in order to benefit from the support services is commercialization. So if Red Hat includes some Apache project’s code that steps on patents, I’d say they are in trouble.
Now, if someone were to “reimplement” a patented drug, the pharmaceutical company sitting on the patent would sue them out of existence the next second without even blinking. Unless I am really badly informed, the entire biotech industry is entirely built on IP protection. All these small biotech firms are doing research that eventually yields protected IP and that’s what they look to turn into profit. They’re not in the business of producing and distributing the resulting drugs on a world-wide scale, they look to share the wealth with the pharmaceutical giants that have the respective infrastructure. The software industry is a very, very tame place against what’s going on in other industries. So will Sun, IBM, Oracle, Apple, and/or Microsoft eventually become more serious about drawing profit from the rights they hold? Right now it would be a very, very stupid thing to do in terms of the resulting, adverse marketing effect.
Now imagine Sun’s unfortunate decline keeps going or some other technology company with a substantial patent portfolio (and not some weak copyright claims) falls into the hands of a litigious bunch of folks as in the case of SCO. That’s when the shit is going to hit the fan. Big time.
Unless you enable the config setting below, WSE injects intentionally invalid “Via” routing information into ReplyTo and FaultTo addresses for security reasons and therefore you can’t just turn around and create, for instance, a new SoapSender(SoapRequestContext.Address.ReplyTo) at the receiving endpoint or set the reply envelope’s context like envelope.Context.Addressing.Destination = SoapRequestContext.Address.ReplyTo. Because “Via” trumps any other address in an endpoint reference for delivery, a reply to such an invalidated EPR will usually yield a 404. I fell into that hole for the second or third time now and it somehow never stuck in long-term memory, so this is the persisted “note to self” 
<microsoft.web.services2>
<messaging>
<allowRedirectedResponses enabled="true" />
</messaging>
</microsoft.web.services2>
I was a little off when I compared my problem here to a tail call. Gordon Weakliem corrected me with the term "continuation".
The fact that the post got 28 comments shows that this seems to be an interesting problem and, naming aside, it is indeed a tricky thing to implement in a framework when the programming language you use (C# in my case) doesn't support the construct. What's specifically tricky about the concrete case that I have is that I don't know where I am yielding control to at the time when I make the respective call.
I'll recap. Assume there is the following call
CustomerService cs = new CustomerService();
cs.FindCustomer(customerId);
FindCustomer is a call that will not return any result as a return value. Instead, the invoked service comes back into the caller's program at some completely different place such this:
[WebMethod]
public void FindCustomerReply(Customer[] result)
{
...
}
So what we have here is a "duplex" conversation. The result of an operation initiated by an outbound message (call) is received, some time later, through an inbound message (call), but not on the same thread and not on the same "object". You could say that this is a callback, but that's not precisely what it is, because a "callback" usually happens while the initiating call (as above FindCustomer) has not yet returned back to its scope or at least while the initiating object (or an object passed by some sort of reference) is still alive. Here, instead, processing of the FindCustomer call may take a while and the initiating thread and the initiating object may be long gone when the answer is ready.
Now, the additional issue I have is that at the time when the FindCustomer call is made, it is not known what "FindCustomerReply" message handler it going to be processing the result and it is really not know what's happening next. The decision about what happens next and which handler is chosen is dependent on several factors, including the time that it takes to receive the result. If the FindCustomer is called from a web-page and the service providing FindCustomer drops a result at the caller's doorstep within 2-3 seconds [1], the FindCustomerReply handler can go and hijack the initial call's thread (and HTTP context) and render a page showing the result. If the reply takes longer, the web-page (the caller) may lose its patience [2] and choose to continue by rendering a page that says "We are sending the result to your email account." and the message handler with not throw HTML into an HTTP response on an open socket, but rather render it to an email and send it via SMTP and maybe even alert the user through his/her Instant Messenger when/if the result arrives.
[1] HTTP Request => FindCustomer() =?> "FindCustomerReply" => yield to CustomerList.aspx => HTTP Response
[2] HTTP Request => FindCustomer() =?> Timeout! => yield to YouWillGetMail.aspx => HTTP Response
T+n =?> "FindCustomerReply" => SMTP Mail
=> IM Notification
So, in case [1] I need to correlate the reply with the request and continue processing on the original thread. In case [2], the original thread continues on a "default path" without an available reply and the reply is processed on (possibly two) independent threads and using two different notification channels.
A slightly different angle. Consider a workflow application environment in a bank, where users are assigned tasks and simply fetch the next thing from the to-do list (by clicking a link in an HTML-rendered list). The reply that results from "LookupAndDoNextTask" is a message that contains the job that the user is supposed to do.
[1] HTTP Request => LookupAndDoNextTask() =?> Job: "Call Customer" => yield to CallCustomer.aspx => HTTP Response
[2] HTTP Request => LookupAndDoNextTask() =?> Job: "Review Credit Offer" => yield to ReviewCredit.aspx => HTTP Response
[3] HTTP Request => LookupAndDoNextTask() =?> Job: "Approve Mortgage" => yield to ApproveMortgage.aspx => HTTP Response
[4] HTTP Request => LookupAndDoNextTask() =?> No Job / Timeout => yield to Solitaire.aspx => HTTP Response
In all of these cases, calls to "FindCustomer()" and "LookupAndDoTask()" that are made from the code that deals with the incoming request will (at least in the theoretical model) never return to their caller and the thread will continue to execute in a different context that is "TBD" at the time of the call. By the time the call stack is unwound and the initiating call (like FindCustomer) indeed returns, the request is therefore fully processed and the caller may not perform any further actions.
So the issue at hand is to make that fact clear in the programming model. In ASP.NET, there is a single construct called "Server.Transfer()" for that sort of continuation, but it's very specific to ASP.NET and requires that the caller knows where you want to yield control to. In the case I have here, the caller knows that it is surrendering the thread to some other handler, but it doesn't know to to whom, because this is dynamically determined by the underlying frameworks. All that's visible and should be visible in the code is a "normal" method call.
cs.FindCustomer(customerId) might therefore not be a good name, because it looks "too normal". And of course I don't have the powers to invent a new statement for the C# language like continue(cs.FindCustomer(customerId)) that would result in a continuation that simply doesn't return to the call location. Since I can't do that, there has to be a different way to flag it. Sure, I could put an attribute on the method, but Intellisense wouldn't show that, would it? So it seems the best way is to have a convention of prefixing the method name.
There were a bunch of ideas in the comments for method-name prefixes. Here is a selection:
- cs.InitiateFindCustomer(customerId)
- cs.YieldFindCustomer(customerId)
- cs.YieldToFindCustomer(customerId)
- cs.InjectFindCustomer(customerId)
- cs.PlaceRequestFindCustomer(customerId)
- cs.PostRequestFindCustomer(customerId)
I've got most of the underlying correlation and dispatch infrastructure sitting here, but finding a good programming model for that sort of behavior is quite difficult.
[Of course, this post won't make it on Microsoft Watch, eWeek or The Register]
News is what is made news.
Point in case: This sentence on my blog here: "There's apparently a related project Boa (another serpent name along the family line of Viper that was the original codename for MTS), including the business markup language BML (pronounced "Bimmel") that he's involved in and he talked a bit about that, but of course I'd be killed if I gave out more details." now prompts, directly or indirectly, this here on Microsoft Watch and this on eWeek.
Nobody said that the project was software in product development. Nobody said it was about stuff that would eventually ship. Nobody really said anything that would be in any way relevant to technical or business decision makers today. What this shows is that there's a bit too much appetite for the next big thing while we're all still working on making the current big thing happen. Do you seriously think I am someone who'd casually leak Microsoft trade secrets on his blog?
And.... seriously.... go back and read the first six sentences on that entry with your brain switched into "active mode".
The recording of last week's .NET Rocks show on which I explained my view on the "services mindset" (at 4AM in the morning) is now available for download from franklins.net
AAMOF, BOA along with BML are PBS TLA's created when we were TUI and MSU while having a late dinner. TMA in this industry and way too much fuzzy MBS. TWOP! IAR, giving out SSI under NDA would get me into VDS, get me?.
(You can speculate all you want in the comments section).
newtelligence AG will be hosting an open workshop on service-oriented development, covering principles, architecture ideas and implementation guidance on October 13-15 in Düsseldorf, Germany.
The workshop will be held in English, will be hosted by my partner and “Mr. Methodologies” Achim Oellers and myself, and is limited to just 15 (!) attendees to assure an interactive environment that maximizes everyone’s benefit. The cap on the number of attendees also allows us to adjust the content to individual needs to some extent.
We will cover the “services philosophy” and theoretical foundations of service-compatible transaction techniques, scalability and federation patterns, autonomy and other important aspects. And once we’ve shared our “services mind-set”, we will take the participants on a very intense “guided tour” through (a lot of) very real and production-level quality code (including the Proseware example application that newtelligence built for Microsoft Corporation) that turns the theory to practice on the Windows platform and shows that there’s no need to wait for some shiny future technology to come out in 2 year’s time to benefit from services today.
Regular pricing for the event is €2500.00 (plus applicable taxes) and includes:
-
3-day workshop in English from 9:00 – 18:00 (or later depending on topic/evening)
-
2 nights hotel stay (Oct 13th and 14th)
-
Group dinner with the experts on the first night. The 2nd night is at your disposal to enjoy Düsseldorf’s fabulous Altstadt at your own leisure
-
Lunch (and snacks/drinks throughout the day)
-
Printed materials (in English), as appropriate
-
Post-Workshop CD containing all presentations and materials used/shown
For registration inquiries, information about the prerequisites, as well as for group and early-bird discount options, please contact Mr. Fons Habes via training@newtelligence.com. If the event is sold out at the time of your inquiry or if you are busy on this date, we will be happy to pre-register you for one of the upcoming event dates or arrange for an event at your site.
We have a bit of a wording problem. With what I am current building we have a bit (not precisely) a notion of "tail calls". Here's an example:
public void LookupMessage(int messageId)
{
MessageStoreService messageStore = new MessageStoreService();
messageStore.LookupMessage(messageId);
}
The call to LookupMessage() doesn't return anything as a return value or through output parameters. Instead, the resulting reply message surfaces moments later at a totally different place within the same application. At the same time, the object with the method you see here, surrenders all control to the (anonymous) receiver of the reply. It's a tiny bit like Server.Transfer() in ASP.NET.
So the naming problem is that neither of "GetMessage()", "LookupMessage()", "RequestMessage()" sounds right and they all look odd if there's no request/response pattern. The current favorite is to prefix all such methods with "Yield" so that we'd have "YieldLookupMessage()". Or "LookupMessageAndYield()"? Or something else?
Update: Also consider this
public void LookupCustomer(int customerId)
{
CustomerService cs = new CustomerService();
cs.FindCustomer(customerId);
}
Carl invited me for .NET Rocks on Thursday night. That is July 15th, 10 PM-Midnight Eastern Standard Time (U.S.) which is FOUR A.M. UNTIL SIX A.M. Central European Time (CET) on Friday morning. I am not sure whether my brain can properly operate at that time. The most fun thing would be to go out drinking Thursday night I want to talk about (guess what) Services. Not Indigo, not WSE, not Enterprise Services, not SOAP, not XML. Services. Mindset first, tools later.
Marcus Mac Innes has a funny collage of our TechEd show. I've spoken to the folks at MSDN and there's a good chance that the video recording will show up on Channel9 soon.
I might be blind to not have seen that before, but this here hit me over the third Guinness at an Irish Pub while answering a sudden technical question from my buddy Bart:
<wsa:ReplyTo xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/03/addressing">
<wsa:Address>http://server/service_second_intermediary</wsa:Address>
<wsa:ReferenceProperties>
<wsa:ReplyTo>
<wsa:Address>http://server/service_first_intermediary</wsa:Address>
<wsa:ReferenceProperties>
<wsa:ReplyTo>
<wsa:Address>http://server/service_outer_caller</wsa:Address>
</wsa:ReplyTo>
</wsa:ReferenceProperties>
</wsa:ReplyTo>
</wsa:ReferenceProperties>
</wsa:ReplyTo>
Read the EPR binding rules section 2.3 in the WS-Addressing spec and you'll find out just like me how distributed "call-stacks" work with WS-Addressing, if your choice of communication pattern is the far more flexible duplex (or here) pattern for datagram-based message conversations instead of the rather simplistic request/response model. Of course, any endpoint-reference can be stacked in the same way. I always wondered where the (deprecated) WS-Routing "path" went, which allowed specifying source routes. I think I ran into it.
I've had several epiphanies in the 12 months or so. I don't know how it is for other people, but the way my thinking evolves is that I've got some inexpressible "thought clouds" going around in my head for months that I can't really get on paper or talk about in any coherent way. And then, at some point, there's some catalyst and "bang", it all comes together and suddenly those clouds start raining ideas and my thinking very rapidly goes through an actual paradigm shift.
The first important epiphany occurred when Arvindra gave me a compact explanation of his very pragmatic view on Agent Technology and Queueing Networks, which booted the FABRIQ effort. Once I saw what Arvindra had done in his previous projects and I put that together with my thinking about services, a lot of things clicked. The insight that formed from there was that RPC'ish request/response interactions are very restrictive exceptions in a much larger picture where one-way messages and much more complex message flow-patterns possibly involving an arbitrary number of parties are the norm.
The second struck me while on stage in Amsterdam and during the "The Nerd, The Suit, and the Fortune Teller" play as Pat and myself were discussing Service Oriented User Interaction. (You need to understand that we had very limited time for preparation and hence we had a good outline, but the rest of the script essentially said "go with the flow" and so most of it was pure improvisation theater). The insight that formed can (with all due respect) be shortened "the user is just another service". Not only users shall drive the interaction by issuing messages (commands) to a systems for which they expect one or more out of a set of possible replies, but there should also be a way how systems can be drive an interaction by issuing messages to users expecting one or more out of a set of possible replies. There is no good reason why any of these two directions of driving the interaction should receive preferred treatment. There is no client and there is no server. There are just roles in interactions. That moment, the 3-layer/3-tier model of building applications died a quick and painless death in my head. I think I have a new one, but the clouds are still raining ideas. Too early for details. Come back and ask in a few months.
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