bottleneck black box

Post #157,228 by tablizer 5/27/04 1:23:42 PM Reply	bottleneck black box OK, so now you're saying your original design won't work. I did not say that. YOU claim it is too slow. I have to take your word for it on faith. It is possible you are just blowing smoke. Maybe if OO or some other goofy practice did not bloat up the REST of the system, we would have more margin for TOP practices. I cannot study your system to see where other bottlenecks may be. What if it's a stateless environment? You have 1200 connections pooled between all the web users, and when a new page is requested global state is cleared from the last user to use that connection. All of the work is done in the database in stored procedures, so you don't have a place to keep cached stuff like that. If you use OO or an OR mapper instead, then something has to store the state between submits. Some web languages allow one to store dictionary arrays in session variables and some don't (out of the box). According to my documentation, ASP can store dictionary arrays as session variables, but I have never tried it myself. One can perhaps serialize/unserialize the array as a string and session it that way, but I don't know if that will add too much processing to your fragile system. ________________ oop.ismad.com
Post #157,231 by ChrisR 5/27/04 1:30:59 PM Reply	Storing Dictionary as Session variables in ASP Them dictionary thingies you refer to are called "Objects". Let's see: Set MyDictionary = CreateObject("Scripting.Dictionary") Behold the power of OOP!!! Seriously though, you have to be careful about the amount of data you stuff in the Session Objects (in ASP and other platforms as well). Memory is a valued commodity on a web server, and if you eat too much of it up with Session vars, it has to start swapping them to and from disk. And then there's the question of distributed web processing, where the service the web page may be distrubuted among several web servers. The Session vars have to be able to pass to the servicing web server, which may not be the one that instantiated the Session. Passing around large objects between servers can degrade the performance.
Post #157,239 by tablizer 5/27/04 1:52:52 PM Reply	It has gotta go somewhere Them dictionary thingies you refer to are called "Objects". That is true. ASP does not have built-in dictionary arrays. They chose to impliment then as an API instead, which means we can't use convenient array syntax. Note that one can implement them using the "handle" API approach also. Thus, we don't need OOP to do the same. Seriously though, you have to be careful about the amount of data you stuff in the Session Objects (in ASP and other platforms as well). Memory is a valued commodity on a web server, and if you eat too much of it up with Session vars, it has to start swapping them to and from disk. That is why I would keep that 600 thingy in tables if possible and let the DB handle RAM caching. But if Scott caches it in RAM, then it is in RAM. It is either in RAM or in tables or in files. Scott's approach seems to be using RAM also. It will have any of the same problems caused by being in RAM as a sessioned array. Interesting material: [link\|http://www.c2.com/cgi/wiki?ProgrammingWithoutRamDiskDichotomy\|http://www.c2.com/cg...tRamDiskDichotomy] ________________ oop.ismad.com
Post #157,241 by ChrisR 5/27/04 2:08:10 PM Reply	ASP is OO Perhaps not done well enuf, but OO none-the-less. Response.Write("I'm an OO method") Session("I'm_an_OO_session_variable") Request("I'm_an_OO_request_variable") VBScript is brain dead when it comes to constructing objects, but you ain't gonna get very far with ASP without objects. Perhaps they "could have", "should have" done it differently - but they didn't - and my guess is that had a lot of "objective" reasons why they chose the path they chose.
Post #157,243 by tablizer 5/27/04 2:28:21 PM Reply	re: ASP is OO Response.Write("I'm an OO method") The first time I saw that, I thought, "oh shit. They borrowed the Java anti-Demeter dot bloat for print()". VBScript is brain dead when it comes to constructing objects, but you ain't gonna get very far with ASP without objects. Do you mean that one has to use existing OOP API's in order to talk to MS services, or that one must create their own classes in order to implement maintainable biz logic? and my guess is that had a lot of "objective" reasons why they chose the path they chose. Microsoft objective? Ha ha. Actually, they tend to copy what a competitor is selling well at a given time. MS is not known to love OO. They were slow to fix the inheritance in VB, for example. ________________ oop.ismad.com
Post #157,249 by ChrisR 5/27/04 2:55:24 PM Reply	ASP = COM The first time I saw that, I thought, "oh shit. They borrowed the Java anti-Demeter dot bloat for print()". It's called COM (component OBJECT model). Do you mean that one has to use existing OOP API's in order to talk to MS services, or that one must create their own* classes in order to implement maintainable biz logic?* Meaning classes are second-class (as opposed to first class) in VBScript. Notes, that they are still useful and used quite a bit in VBScript. Microsoft objective? Ha ha. Actually, they tend to copy what a competitor is selling well at a given time. MS is not known to love OO. They were slow to fix the inheritance in VB, for example. And I thought you were keen on MS, seeing as how Longhorn is trying to use SQLServer for the File System.
Post #157,258 by tablizer 5/27/04 3:18:32 PM Reply	re: ASP = COM It's called COM (component OBJECT model). I meant the syntax, not how it is implemented. Hmmm. I wonder how closely the ChiliSoft ASP clone sticks to the COM model? Meaning classes are second-class (as opposed to first class) in VBScript. What is the difference between second-class classes and first-class classes? Nah. maybe I don't wanna know. And I thought you were keen on MS, seeing as how Longhorn is trying to use SQLServer for the File System. MS does some things well, and some poorly. I will praise them for good stuff, and cuss them for stupid stuff. For example, I like the case-insensitivity in their tools. But their default of "smart quotes" in Word really sucks. ________________ oop.ismad.com
Post #157,262 by ChrisR 5/27/04 3:33:09 PM Reply	ChiliSoft ASP I've not done more than play with it, but the ChiliSoft ASP works pretty good. Biggest problem is how well it deals with custom COM components written in VB and C++. It does provide a COM-like container, but it works only so far. If you stick with the standard five ASP objects (Application, Response, Session, Request, Server) and the four standard VBScript objects (Err, Dictionary, FileSystemObject, TextStream), then you won't have too many problems. Anyhow, the way Chilisoft implements ASP is by using OO programming techniques. But then, somehow I know you knew that I would say that. What is the difference between second-class classes and first-class classes? Nah. maybe I don't wanna know. Generally speaking, it's the ability of the language to add libraries to itself, and not have the distinction between those libraries you wrote vs. the standard libraries that come with the environment. MS does some things well, and some poorly. I will praise them for good stuff, and cuss them for stupid stuff. For example, I like the case-insensitivity in their tools. But their default of "smart quotes" in Word really sucks. So when they agree with you - they are being rational. But when they make a design decision you disagree with - they are being irrational.
Post #157,275 by FuManChu 5/27/04 4:19:21 PM Reply	Interesting terminology What is the difference between second-class classes and first-class classes? Nah. maybe I don't wanna know. Generally speaking, it's the ability of the language to add libraries to itself, and not have the distinction between those libraries you wrote vs. the standard libraries that come with the environment. I would have thought: first-class classes are themselves objects which can be passed around. Second-class classes are not objects. Both can be used to create objects, but only one is itself an object. Or something.
Post #157,279 by ChrisR 5/27/04 4:32:41 PM Reply	You're probably correct convention-wise (Had a link I was gonna post on the subject matter of "first-classness" have to do with first class messages, but the site is unresponsive at the moment). Anyhow, from my standpoint, I do think that the ability to build libraries from the language should count for something (should probably invent a new term like VBScript is Adjective and/or Adverb based - not Noun or Verb based).
Post #157,259 by admin 5/27/04 3:30:05 PM Reply	Re: bottleneck black box OK, so now you're saying your original design won't work. I did not say that. Yes, you did. Your initial design was [link\|/forums/render/content/show?contentid=156950\|put all the "features" in the client table]": // select login strategy\ncustomer = query('select * from customer where id=...)\nstrat = customer.loginStrategy\nif strat='A' then\n....\nelseif strat='B' then\n...etc... So I asked, what if you have 600 "features"? At which point you said use a different table. So the original design won't work, correct? As a matter of fact, 600 was just a number I pulled out of thin air. Checking the code (with grep, natch), we have about 4000 instances of parm-based decisions being made, and 10,000 instances of "if client = foo" decisions being made. Maybe if OO or some other goofy practice did not bloat up the REST of the system, we would have more margin for TOP practices. Again, 1 million lines of PL/SQL code. 99.3% of the system is OO, and that's the bridge login. And any margin is going to go towards adding more clients to the system and doing useful work, not supporting poorly performing, unnecessary practices. If you use OO or an OR mapper instead, then something has to store the state between submits. We're not talking about OO. We're talking about doing everything in the database. Web request comes into Apache, mod_plsql determines that a particular URL maps to a particular PL/SQL package, and the rest is ALL database code. This is a stateless environment. Since you can't cache (the connections have DBMS_SESSION.RESET_PACKAGE called on them between pages), the parm table becomes a performance bottleneck. And the system is hardly fragile. We have 400K pieces of inventory. Half a million users. 10 million users if you include representatives (look around: 1 out of 30 people you know uses our system in some way). We process a good 20% of all the transactions in our market. A billion dollars changes hands through our system every day. There's just no room for performance-sucking crap that doesn't add any value. And in fact, the whole procedural hairball doesn't scale as well as it needs to, so we're moving away from that now. And given your utter lack of experience in this arena, nothing you would be able to tell us after looking at the code is going to help, especially since you're not proposing anything we aren't already doing, albeit on a much larger scale than you've ever contemplated. Regards, -scott anderson "Welcome to Rivendell, Mr. Anderson..."
Post #157,265 by tablizer 5/27/04 3:47:54 PM Reply	how they relate I am confused about how the config params relate to the login strategy, other than containing the strategy name as one of the params. ________________ oop.ismad.com
Post #157,271 by admin 5/27/04 4:11:02 PM Reply	Re: how they relate Login params are a configuration value. Just like all the other 4000 configuration values. It's a value used to determine what to do at a branch point: which decryption method do I use? which parsing method? what's the timestamp window? what's the home page? This is classic control table technique. So your suggestion now is to just store bridge login parm values in the client table? Where do you draw the line? Why not the client's account control parms, or their routing parms? Regards, -scott anderson "Welcome to Rivendell, Mr. Anderson..."

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