E-commerce with mod_perl and Apache 174
rob_99 writes: "Cool new mod_perl article at perl.com documents building a large scale ecommerce solution w/ mod_perl & apache!" Pretty cool stuff - it's kind of funny to think how ephemeral their work turned out to be.
Case Study: eToys.com (Score:2, Offtopic)
Interesting to since what was nappening behind the scenes away from the marketroids.
Re:Case Study: eToys.com (Score:1)
Re:Case Study: eToys.com (Score:2)
Sorta
So is this the best example to use for a successful implementation of mod_perl?
eToys went down like a lead zepplin (Score:2, Interesting)
In November, eToys had over well over 1000 employees. By March, they had fired all but a 10-20 employees (all management), and most of those people are gone by now. Few of these 1000 employees received their full severance package because eToys had no money (This was a violation of the contract, but suing was a lengthy and tedious option).
Between December of 1999 and December of 2000, eToys burned though several *HUNDRED* million dollars in funding.
KB Toys bought the eToys merchandise (toys), the eToys brand, some of the computer hardware (but not the intellectual property needed to maintain it, e.g. the engineers and administrators), and I think the warehouses (One of the warehouses was a $20-million high tech warehouse).
That counts as going under.
Their only successful subsidiary, Babycenter.com, lives on. But they don't use mod_perl (It's an Apache + java application server shop).
difference between mod mod_perl? (Score:3, Funny)
17 mod_perl 5 = ?
Re:difference between mod mod_perl? (Score:1)
What the heck is ephemeral?? (Score:4, Funny)
Adjective
1. Lasting for a markedly brief time: "There remain some truths too ephemeral to be captured in the cold pages of a court transcript" (Irving R. Kaufman)
2. Living or lasting only for a day, as certain plants or insects do.NOUNA markedly short-lived thing.
ETYMOLOGY From Greek ephemeros, ep-, epi-, epi-, + hemera, day
Just in case your vocabularly sometimes leaves you wondering (as mine does).
Re:What the heck is ephemeral?? (Score:3, Funny)
Re:What the heck is ephemeral?? (Score:2)
No, he meant short-lived. The company (etoys.com) mentioned in the article is tits-up.
mod_perl is definatly ready (Score:3, Informative)
The key part is that I was in charge of the perl backend, and it was really lagging. Loaded mod_perl up and *bam*, we had a fast enough system. I never did a serious benchmark, but it was like 100% improvment
Thus all I can say is good job guys! This doesn't surprise me at all, and it's good to see recognition get passed around in the correct quantity for once
I'm just glad they didn't try to convince me... (Score:3, Offtopic)
Load balancing (Score:1)
The application servers use "sticky" load balancing. That means that once a user goes to a particular app server, all of her subsequent requests during that session will also be passed to the same app server. The f5 hardware accomplishes this using browser cookies.
Doing something similar, I just hashed the users IP, mod by the number of servers, and sent it to that particular server. (ie. 10.0.0.1 = 0xA000001, 0xA000001 % 0x0A = 0x01, hence send to server #1)
In case of server failure, the sessions might get unstuck from the server, but that shouldn't happen often enough to be much of a performance hit.
Why? (Score:2, Interesting)
Re:Why? (Score:1)
using a SAN/NAS for
need to stay tied down to your session
data. Sure you could put it on a SAN/NAS
or on some remote database, but why?
It's temporary and the other servers don't
really need it, that would just slow the
system down.
Re:Why? (Score:2, Interesting)
We have an entire centralized server that does nothing but serve session data. From the ground up the server and database is optimized for serving session data.
Works quite nicely
Jeremy
Re:Why? (Score:2, Informative)
Re:Why? (Score:1)
This is a bad idea (Score:1)
Re:This is a bad idea (Score:1)
But if you XOR it with timestamp it should be fine. Better choice might be the sessionid or anything else that is actually random.
Re:Load balancing (breaks with NAT) (Score:2)
Servlet container maybe... but application server? (Score:4, Interesting)
But an application server it is not. Container managed persistance, transactional support, message queues, naming and lookup services? Integration with existing business objects and processes? These aren't trivial in Perl, but they are the core functionality of app servers. They pulled off clustering for eToys, but it was hardly an out of the box solution.
If all you want is a servlet container, don't spend the money on an application server. Tomcat works great and iPlanet bundles one with their web server.
Re:Servlet container maybe... but application serv (Score:5, Insightful)
Re:Servlet container maybe... but application serv (Score:2)
I hope that by now, e-commerce should not be an interesting problem at all. It's a standard business practice that ought to have simple (and secure) OotB solutions.
Re:Servlet container maybe... but application serv (Score:4, Insightful)
If you are just selling products in a plain way, you can get simple enough e-commerce. But if you want to provide good e-commerce that ties in with other content, again there are no out-of-the-box solutions. Also, you have to be happy with a out-of-the-box appearance, where you get to control a few graphics and colors on the page, but the essential layout is fixed. It's usually (but not always) pretty easy to change layout -- but that's still not really out-of-the-box.
Re:Servlet container maybe... but application serv (Score:3, Insightful)
Ok, I'm going to try you on this. Reason is, I've written fairly serious server code in Java, and didn't use many "application server" facilities, because I didn't see the advantage.
Container managed persistance
Far as I can tell, this saves you writing some trivial SQL statements. Plus, as soon as you have any interesting data (ie, not just one row in a table) or performance needs (this is backed up by benchmarks by an experienced app-server user), container manager persistence is impractical anyway, so you have to learn how to do it yourself.
transactional support
Unless you have some exotic need, a transactional data store is the beginning and the end of the solution.
message queues
Easily implemented over an SQL database (I wrote some pseudo-code, but it's too hard to format in slashdot).
naming and lookup services
I know Java has some facilities for this, but what do they do that's not easy with LDAP or similar?
Integration with existing business objects and processes?
You'd be surprised how many of these are already in Perl. :-) That aside, most of this means accessing an SQL database. I mean, sure, Java will integrate better with a Java shop and other Java software, if that's important.
They pulled off clustering
Pretty easy with a remote data store.
Re:Servlet container maybe... but application serv (Score:2, Informative)
I think you're over-stating the necessity of these things. Container managed persistence is often a way to replace one short SQL statement with 3 long XML files. Message queues are trivial in a good database (Oracle). Naming and lookup services are need if you're using EJBs, but we didn't need EJBs.
They pulled off clustering for eToys, but it was hardly an out of the box solution.
How do you define out of the box? We didn't do much work beyond the custom programming that was needed for our application. The open source components filled in our anfrastructure needs very nicely. It wasn't a "packaged solution", but it was easier than many commercial packages I've had to use in the past.
I love Perl. (Score:1, Flamebait)
Re:I love Perl. (Score:3, Informative)
Re:I love Perl. (Score:1)
Re:I love Perl. (Score:1)
There are a bunch of compilers out there already that compile Java to native executables. They never took off because the performance increase wasn't as impressive as you would think.
Re:I love Perl. (Score:1)
as far as those niceties hampering performance... it is true. cool things like garbage collection trade ease of coding and safety of code for a loss of speed. however, c# supports stepping out of the runtime and write "unsafe" code. basically forgoing the sandbox, allowing you to do "fun" stuff like pointer operations and such. for even more leeway, you can step out into managed c++, all without losing interopability with all other
at any rate, regardless of all this functionality... writing straight to the clr classes without dropping out of it will still be much more performant than mod_perl can be. along with all the goodies that the starter of this thread pointed to.
Re:I love Perl. (Score:2)
A variable exists whethoer you declared it on line 1 or line 500. There are many benefits to this. I'm talking from a developers perspective - byte-code gives me the same end result (essentially).
Re:I love Perl. (Score:3, Interesting)
This leads to a total mess, and even when the mess is kept under control it's usually with lame templating techniques like having a standard header and footer, which are initially expedient but not very flexible. "Initially expedient" is exactly what the *SP languages achieve, but at the price of later ease of development.
Of course, you can use any of those languages with a <% at the top of the file, and %> at the bottom, with an entirely seperate templating solution, but that kind of renders the whole point of those implementations moot. In my own experience with PHP, my code has started as normal, mixed-HTML/PHP code, and eventually ended up as just one chunk of PHP code.
mod_layout is your friend (Score:2, Insightful)
Re:I love Perl. (Score:2, Informative)
I can't say I agree that JSP, ASP, PHP, or any of the *SP family of languages are good design. They encourage exactly the opposite of MVC, they encourage you to mix HTML and (non-display related) programming code.
This is why n-tier apps were invented. Javabeans, COM components, whatever. Just because you can put logic in your pages doesn't mean you should. Gives you the option to run threads asynchronously and/or via message queuing and increase your performance considerably.
Remarkably, in my experience building high performance (not necessarily highly scalable) sites, I've learned (from pain and suffering and/or other coders) that building those strings to push outo the buffer is often very expensive. You wouldn't think...
The other lesson I learned is the value of profiling tools. Particularly tools to show you what is going on at your database and a sniffer to show you what's going over the wire under load. I found problems that I would never have noticed without these tools.
*SP and MVC (Score:1)
We rearchitected the system around XML/XSL, assigning the webmonkeys (ahem) to the XSL layer to compose views based on a standard XML document structure. Client requests were dispatched to function handler objects by a mediating servlet, and then to the back-end business logic.
We lost a lot of flexibility by eschewing JSP, but that was part of the goal, which was the result of a lack of discipline on the part of the presentation developers. Taking away a lot of their options didn't solve all of the problems, and introduced some new ones[1], but it simplified QA remarkably and reduced my headaches.
[1]: We had to operate in lock-step. As presentation is sometimes much easier to develop than business logic, the XSL developers often had to wait, none-too-quietly, for adequate function handler and XML-generation code.
Re:I love Perl. (Score:3, Interesting)
Every time I see a post like this, I have to ask...what do you think of 'normal' gui applications? ie, GTK or even raw X11 Protocol stuff? You certainly don't separate your interface from the code driving it there, so what is your point with embedded scripting? Seriously.
On a good team, embedded stuff is a joy. You can have your layout artists do their mockup, and then you just insert the code into their mockup to make it all work. The layout guys can still use their gui publishing tools, and you just have to link the code to the forms. Dangerous with idiots, but very effective when the page layout guys are smart enough to keep their hands off anything between the [($|-|+|#]'s
Re:I love Perl. (Score:3, Interesting)
Perl is highly flexible and can be very modular if you code it properly. My web page isn't a great example, but I do use one module on it
Re:I love Perl. (Score:3, Interesting)
I can't say I agree that JSP, ASP, PHP, or any of the *SP family of languages are good design. They encourage exactly the opposite of MVC, they encourage you to mix HTML and (non-display related) programming code.
As it has been pointed out, at least with regards to JSP, "allows" does not mean "encourages". And talking about MVC, you should take a look at one [apache.org] of the many [apache.org] "MVC"-like implementations for Servlet development (be it using JSP or not).
Re:I love Perl. (Score:4, Insightful)
Using Perl as opposed to, say, Java or C++, is like using Emacs as opposed to Notepad.
You can learn Notepad lickety split. You'll get alot more done if you know neither and have to get something done in a single day.
But over the long haul, you'd be far better off using Emacs.
Perl (and Python) are the same way: If you turn a bunch of inexperienced coders loose with no oversight and no structure, you'll get crap. But if you have a team of experienced Perl programmers, they will beat the pants off of any team of, say, C++ developers in terms of development time any day of the week.
Not to detract from C++. I am simply saying that the languages are used for different things, and that poor code follows from poor coding standards and practices, inexperience, and unorganized minds.
So if you can't write Perl without seeing spaghetti, I would suggest you have either some learning to do or that you need more discipline in your coding practices.
Perl + e-Commerce in the field (Score:5, Insightful)
There's a second downside: lack of good SSL networking. SSL is critical for credit card processing. I ported the GPL version of TCLink [trustcommerce.com] for Perl, and we ran into a lot of problems due to lack of a standard SSL library. For the first version of the client we ended up distributing a patched version of Net::SSLeay which added all of the certificate authentication functions we needed (and are missing from the standard install of Net::SSLeay). Later this became such a headache for the various platforms we were trying to support that we just coded a
Long story short: sure, Perl's great. Is it the best choice for e-commerce? I'm not so sure.
Re:Perl + e-Commerce in the field (Score:2, Informative)
We also use HTML::Mason - the best mod_perl add on period.
Granted, we're not handling the volume of transactions as an eToys.com, but we use an extremely similar hardware configuration and have been running successfully without issue for quite some time.
I cannot recommend Raven's SSL and HTML::Mason enough.
Jusy my 2 cents
I don't think thats what he meant (Score:5, Informative)
TrustCommerce [trustcommerce.com] offers a drop in .pm module as well for people writing perl front ends to their web sites. The Raven SSL package allows apache to serve https, not make ssl connections from a perl program. The trouble with SSL in perl is not serving https+mod_perl, its in writing those easy drop in .pm modules for connecting to the eCommerce gateways. Lucky for all you eCommerce site developers, we gateway programmers get to worry about that, not you.
I don't think Adam's comment was meant to detract from the power of something like Mason and mod_perl for developing web site front ends. It was just that of all the API's we have open source libraries for (C, Perl, J2SE, J2EE, Python, PHP and ColdFusion), the Perl module was by far the hardest to develop as the existing tools lack some important features.
Re:Perl + e-Commerce in the field (Score:2)
Do a lot of people use mason? When the subject of embedding code in HTML comes up the only thing people talk about is PHP. I've used mason for personal stuff, but at work it was decided that PHP was the choice. I'd like to hear about anybody using mason in any serious way.
For the curious Mason vs PHP: I havn't been really impressed with PHP. It does what it advertises but I havn't seen anything that it can do that perl can't do. I also havn't seen it do anything better than perl, with the exception of it's treatment of arrays and hash's which is a great way of unifying the two concepts. One PHP negative is that it doesn't have the extensive library support that perl does. It has pear, but it doesn't seem very developed. I guess if you're learning a new language, why waste your time on php when you could learn perl and use mason, and when you were done you'd have transferable perl knowledge?
Re:Perl + e-Commerce in the field (Score:2, Insightful)
Wow. (Score:3, Interesting)
But I gotta say, I would have loved to have been on that team for that. Though I would have rankled at the suggestion of needing "help" with object oriented programming, it would have been worth it to meet those two.
OO Maintainable Perl.. (Score:1, Flamebait)
For all the good(ish) things about perl (a massive developer community, libraries to do ANYTHING, reasonable performance under mod_perl, and instant recognition), describing perl as:
'Through the use of Perl's object-oriented features and some basic coding rules, you can build a set of code that is a pleasure to maintain, or at least no worse than other languages.'
is rather laughable.
Perl has a tacked-on-the-side OO layer that kind of works if you are careful, and I don't think anyone would argue against the well known write-only feature of perl code. Maintainable yes, equal to other languages? Less likely.
However, I find the most interesting part of the article the switch from MySQL (popular, but has REAL trouble scaling, I know I will get flamed for that, but it is my real experience) to Oracle. I wonder what other systems were tested? If they were getting a significant speedup with a berkely-db cache of serialised objects, then they were not getting a lot of performance from their database.
I would have been very interested in a comparison between their Oracle setup and a PostgreSQL system, given their need for local caching running a PostgreSQL cache on each machine could have been quite a win.
Their code samples given certainly do not represent 'clean and maintainable code' to my eye. perhaps they should invest in a python book, possibly the most readable language I have yet found (but will not stop looking).
Re:OO Maintainable Perl.. (Score:5, Insightful)
Object Oriented Perl [slashdot.org] is extremely powerful and flexible. It's possible to do exotic things like multiple dispatch, it *does* support true encapsulation, and you can change inheritance hierarchies at run time. I've seen people write first-class objects and classes (think Self), and I've implemented mixins having seen them in Ruby. You can use all sorts of design patterns, have compile time member checking, and even modify objects as the code is running. There are even good reasons to use multiple inheritance (Perl's not the kind of language that thinks it's smarter than you.)
If you mean "member data tends to be class based instead of object based", then you're right. That's a true limitation of OO Perl. It would also be nice to have a refactoring browser like Smalltalk has.
As for readability, I can't read anything written with Kanji characters. That doesn't mean I'll ever claim it's "unmaintainable compared to English". (To be fair, complex data structure dereferencing *can be* hard to read in Perl.)
Re:OO Maintainable Perl.. (Score:3, Insightful)
Except for this...
To be fair, complex data structure dereferencing *can be* hard to read in Perl.
Yes, but(tm)... In the context of OO, you should never have to dereference a complex data structure. You shouldn't have to know a dang thing about the structure.
Regardless, I've found people squawking about the "write only" feature of Perl all share a common feature amongst themselves. None of them write Perl.
Go figgure.
Re:OO Maintainable Perl.. (Score:2, Insightful)
Maintainable yes...
Which is it? Write-only, or maintainable? My guess is maintainable, because I have never once heard one with a solid understanding of regular expressions state that perl is "write only".
Why use mod_perl ... (Score:2, Insightful)
It seems like the better choice would be to avoid using modules altogether. Or using another language like C or PHP that has stuff built-in. It's amazing how much CPU time loading a simple perl module takes.
Re:Why use mod_perl ... (Score:5, Insightful)
Even if you don't use modules (which would be silly, roughly comparable to not using sub-routines), you still incurr the penalty of loading and compiling your scripts each time they run if you don't use mod_perl. Also, mod_perl gives you amazing control over how the requests are interpreted and responded to. But even if it it didn't, a 5 or 6 to 1 improvement in requests/second (which is what I saw just by using mod_perl to run the script, with little of no optimization) is nothing to sneeze at.
not too surprising... (Score:1, Insightful)
This article drives home a very good point: sound architectural design is what makes a complex system work. If you know what the big picture looks like, you can fill in the details whichever way suits you.
Perl has a strong nice -- more than you think (Score:5, Interesting)
[quick disclaimer, feel free to use ruby or php for a substitute for perl below]
Perl is very good for a much larger range of projects than you think. [with a HUGE deference to C++/OO people, see note at bottom]. Very few sites rely on pure computational power. Most sites only need a small compenent to be fast, and that you can implement in the language of you choice with perl bindings. The majority of your site is glue -- and this is what perl does well.
I worked for a small team (5 developers) that wrote 200k lines of perl in a year and a half. That represents a far larger body of code if it had been written in another language. That isn't to say you lose control by using perl. You get to ignore the details, and in the bargain get a perfect language (and some extra time) to write regression tests.
All in all, unless you are a games site that cares about milliseconds, you can get a page out the door in under
-spRed
the deference to OO folk, you can teach people who only know C++/Java perl, you can't teach people who only know perl the others. The reason why is that real CS educations are portable. Perl [and other interpreted languages] are looked down upon by CS folk - so only non-CS folk will persue perl as a primary language. Perl is, however, extremely useful for whatever you are doing (95% of you). Give it a chance, it will save you alot of time in the long run.
Re:Perl has a strong nice -- more than you think (Score:1)
1s/nice/niche/
Re:Perl has a strong nice -- more than you think (Score:4, Insightful)
Re:Perl has a strong nice -- more than you think (Score:3, Informative)
Re:Perl has a strong nice -- more than you think (Score:2)
All the more reason intellegent computer scientists won't be biased against Interpreted languages.
CS folk breakdown (Score:1, Funny)
Most Computer Science majors are lazy, therefore they think that perl is amazing. They hate prolog because it is radically different. They know C++ and Java, but for quick jobs, they go with perl.
Most Computer Science professors hate teaching perl (at least for intro stuff) because the syntax is crazy. They love prolog because the students hate it and most of them are crazy and love everything, except for teaching perl to newbies.
CS alumni program in whatever language their job requires!
You should be safe then (Score:5, Insightful)
Like the subject says, you should be safe in your career. After all, you know The One True Programming Language, right? Perl isn't a toy, though, is it? I mean, if it's functionally equivalent with Ruby or PHP in all respects then it must be worth something, right? (Just don't let those interpreted guys into the Compiled Officer's Club... they might tell wild stories about getting lots of work done really quickly or spread notions about non-compiled languages being the right tool for the job...)
Seriously (or maybe not), perhaps you could check your OO bigotry at Dr. Dobbs door when you come slumming it in Scripting Land? I know some of us started using Perl before a "real" language like C++ or Java, but that doesn't make us unable to learn that real language, does it? Does it mean that we won't be able to get real work done? Are the sites we work on less useful to you?
Why would you look down on someome who has started out with Perl? I started out in the computing world using BASIC on my VIC-20. I didn't have the luxury of Java or C++. Do you think I can still learn? Am I worthy? Can I evolve to your level? Will I ever be able to look down my OO nose at mere scripters like you do? Can I be effete?
Ok, sorry to bait you. I use perl as much as I use shell scripts. I no longer use BASIC or Pascal and I'm glad. Quick and dirty GUI apps in C and C++ are a pipe dream -- Java works very well for that (especially when your app has to very quickly work on everything from BSD to WinNT). But I hate to break it to you: I have no CS eductation. The only CS course I ever took I wound up teaching. Should I resign from my job? Am I doing my company a disservice by "trying" to write OO Java apps for them since I don't have a "real CS education"? Are the OO perl apps I've written even OO enough to get me in the club? Are my C apps more portable than my lack of education? Are my Java apps?
You should realize that your "real" CS education bought you knowledge, but not at the expense of anyone else's abilities. Software Engineering is not a zero-sum game; we can all play without dimishing the accomplishments of others. But if you need to feel important, then I guess your post is like therapy for you or something...
Life is too short to be a snob.
-B
Re:Perl has a strong nice -- more than you think (Score:2, Insightful)
I earned a Bachelor of Science in Computer Science, which I received in May after completing four years of computer science coursework in a CS department that was focused on the OO development model. We did most of our advanced development in C++, so I got plenty of exposure to that. I learned it well enough to get satisfactory marks (mind you, I didn't get perfect marks, but I at least showed that I could use what I was learning).
Now? I am working at a large e-commerce company, developing website/database functionality in Perl. Perl is my primary language. In fact, including me, five out of the six developers in my department earned their BSCS at the same college. We all program in Perl. We also write a lot of modules to encapsulate functionality for our site, and write/use them in an OO manner. Some of us are not as crazy about OO as others, but we all use it. We have certainly never 'looked down upon' Perl.
Seen this at Apachecon (Score:1)
This paper was presented by the authors at Apachecon 2001 in Santa Clara, last April. The [ApacheCon.com]session info [apachecon.com] is still (sort of) online. Cool stuff.
Serious Scalability (Score:4, Interesting)
I often read articles saying perl/mysql can't handle enterprise solutions. Well, it can, does and is doing so in our case. Like any tool, it's as effective as the people wielding it.
We also have a huge codebase in C/C++, Java, Python and a few others. There's even a few NT boxes thrown in for dealing with some obscure hardware. I'm not particularly bias one way or the other, I just need the results.
By the by, I do have one solution for ensuring my programmers don't take sloppy shortcuts and write obviously quick and dirty code. It's the pink slip method. I find it works equally well in any language
Robert Nice
WebsiteBilling.com Inc.
Re:Serious Scalability (Score:2, Interesting)
While I think all software does indeed have limitations I think developers tend to impose artificial limitations.
I don't like mySQL all that much but I will be the first to admit I have been a part of a team that forced it to scale. Uhm MySQL doesnt scale? Look at what your posting to! Slashdot isnt even a massive web cluster or anything and it handles the load quite nicely. We used PHP, SQUID, and mySQL in combination to make the system scale absolutely through the roof.
It is all about the developers in most cases!
I also don't like Perl and would not choose to implement in it but I find the claims that its impossible to write clean code in it a little far reaching. I have seen Java, C, PHP, and Perl written well. I have also seen code in each language an indecipherable jumble of spaghetti code (even in Java and even worse in PHP)
So anyway...use technology that gets the job done and keeps you in the green.. stop fretting about the small stuff (and its all small stuff
Jeremy
MVC + XSLT + Python (Score:2)
I'm looking at setting up a similar type of system using postgres, apache, mod_python, and XSLT. Has anyone else ventured down a similar path?
Re:MVC + XSLT + Python (Score:2)
I personally, like to use C and DB files for most things (I don't need Oracles firepower, complexity, or price :)
My templates look something like this:
${include head.html}
<form method=post action="${path_url}">
$?{messages}${messages}<hr>$.
$?{gt ${v_count} 0}<table border=1>
<tr><th>Mark</th><th>Volum e Class</th></tr>
$@{for i 0 lt ${v_count}}<tr>
<td>${radio volclass ${v_class[${i}]}}</td>
<td>${v_class[${i}]}</td>
</tr>$.
</table>
<input type=submit name=action value="View/Edit Properties of Marked Class">
<hr>$.
$.${include buttons.html}
</form>
${include tail.html}
Re:MVC + XSLT + Python (Score:2)
I use Webware myself, and quite like it. Similar to Java Servlets, without the verbose language. I haven't used SkunkWeb myself, but it looks reasonably mature (it's at v3, where Webware hasn't quite reached 1.0 yet... but that doesn't necessarily mean much).
So, what's different from RH Interchange here ? (Score:1)
Mod_Perl vs. XML issues resolved? (Score:2)
.
Re:Mod_Perl vs. XML issues resolved? (Score:3, Flamebait)
As a result, Perl parsers for HTML, XML, and SGML typically have the tokenizer written in C. "expat" is the low level part of an XML parser written in C. So Perl programs that parse HTML, XML, or SGML typically have a C component.
That C component has to go into the Apache server (and run with server privileges, with all that implies, like a potential for buffer overflow attacks) for mod_perl programs to use it.
It's an annoying limitation of Perl.
Re:Mod_Perl vs. XML issues resolved? (Score:5, Informative)
Complete and utter BS.
What are "server privileges" ? Everything in apache runs under the nobody user (or configurable).
What potential for buffer overflow attacks? Show me one.
The component does *not* have to go into the Apache server for mod_perl programs to use it. Not even slightly. If that were the case, DBI would be unusable from mod_perl, wouldn't it? No-siree, the C component (expat) was included in Apache to support mod_dav. They modified expat slightly (and called it expat-lite), and thus we had symbol conflicts, and the wrong code being executed, and BOOM. So now Apache 1.3.22 uses the DSO expat, same as XML::Parser does, and the problems are gone.
Someone please mod me up or him down. Facts can be checked in the mod_perl and mod_perl-dev list archives.
Re:Mod_Perl vs. XML issues resolved? (Score:4, Informative)
Whats wrong with this ?
Admittedly the split function can't work on individual characters as it needs an IFS but substr seems to work ok for me.
What about this
Or have I misunderstood ?
Perl vs. get char (Score:2)
That's only useful if the "s///" operator controls an inner loop. If you have a program where the high-speed loop is the outer loop, like a parser, that trick doesn't help.
Go read the comments for HTML::Parser before the C version.
Re:Mod_Perl vs. XML issues resolved? (Score:3, Informative)
Re:Mod_Perl vs. XML issues resolved? (Score:2, Informative)
Seriously, it wasn't a problem with mod_perl, but the way Apache would be built.
It's been fixed in the latest rev of Apache.
eToys had over 100 people coding HTML (Score:3, Informative)
mod_perl definately has it's uses, but eToys is a bad example. Remember, eToys went out of business, in part because they spent way too much money on hardware and had way too many employees doing simple jobs.
You would think a large site like eToys would make good use of templates and would reuse programming objects all over the place. This wasn't the case for eToys at all.
eToys initially felt it was too difficult to use mod_perl to create templates or reuse objects on their site. They almost never reused elements in their pages, and they had very few templates. There was hardly anything there you could call an 'application server', and most of their pages were not dynamic (outside of store item entry).
Instead, they had over 100 HTML people to write the HTML for just about every single page on their site. It wasn't a very large site either. When I say 'HTML', I don't mean 'they wrote DHTML or PHP or java or perl. They had 100 people writing plain vanilla *HTML*.
Towards the end, eToys hired a few smart folks who knew the capabilities of mod_perl. They were on their way to creating a templated dynamic site. In the middle of this new effort, they went bankrupt.
(I used to work for eToys. Posting as AC to protect me from Toby Lenk's lawyers).
Re:eToys had over 100 people coding HTML (Score:2, Informative)
I was in the tech suite and never saw "100 coding HTML". Lots of Oracle DB staff, Perl programmers, a few admins and some misc employess. In fact, during the all hands tech meeting (when the laptops got stolen) I don't think there were 100 people in the ballroom.
Why Oracle? (Score:2)
This is just a question. Use your mod points on good answers. (-:
I don't need no steen'kin karma!
Re:Why Oracle? (Score:1)
These may have influenced thier decision.
Also with Oracle you get that on phone support should anything go bump in the night.
Re:Why Oracle? (Score:2, Insightful)
Why? Business and partnering. Not technical. When the CEO was in meetings with possible partners and said "MySQL" when asked about our database, he got wrinkled noses and confused looks (mys..what?) in response. When he said "but we are migrating to Oracle," the result were ohhhss and hhhhhaaaa. Sigh.
Once the technical team got into Oracle, they liked it and started to use various features that MySQL didn't support (at the time). I can remember doing rollbacks more than once while handjamming SQL code before a demo.
Nonetheless, I think we all remain MySQL fans.
Re:Why Oracle? (Score:2, Interesting)
If only.. (Score:2, Interesting)
I think that it's due to marketing. If the open source movement paid for advertising, publicity, etc, then a lot more people would consider the open source alternative, but they opt for the large company with marketing, and reps, and so on....
Re:If only.. (Score:4, Insightful)
Because just like Apache/Perl or JSP/Servlets, PHP etc. ASP can also be an adequate environment for large-scale solutions if someone with enough experience is using it. If you throw enough brains and money on a problem set, you're bound to get a good answer, no matter which technology is used (unless it has some fundamental deficiencies, of course).
As far as the article is concerned - I doubt that more than the top 1% of experienced Perl programmers could build anything like that...
How many 'nodes'? (Score:2)
Not impressive, if those numbers are right. (Score:2)
If they really were doing 2 million page views per hour, that's about 600 page views per second. Across even JUST the 40 'dynamic page builder' servers, that's 15 pages/second. If you include the reported 20 static page servers, you get 600/60 = 10 pages per second. Certainly nowhere near taxing on a dual P450, ime.
What this really points out is that people need to spend more time engineering solutions rather than buying 'scaleable enterprise fill-in-the-blank' for hundreds of thousands of dollars. Again, just mho.
Interchange (Score:2)
Re:PERL - the "Write-Only" language... (Score:1)
These things are convient shorthand, not unreadable code, if you spend some time with the language.
Re:PERL - the "Write-Only" language... (Score:1, Informative)
We use Embperl, which is Perl tags in HTML, like PHP. Embperl is very impressive.
I learned Embperl before PHP. Now I'm learning PHP on the side and feel that it is lacking features which Embperl includes. For example, in Embperl, I don't have to do "stripslashes" or "addslashes" when I read from a database. This makes the code cleaner. Also I can use straight HTML in between conditional statements without having to use "print" everywhere.
[$ foreach $key ( keys %ENV ) $]
My key is [+ $key +], which is [+ $ENV{$key} +]
[$endforeach $]
Nice and clean code
Re:PERL - the "Write-Only" language... (Score:2, Informative)
As for too many print statements you can do <?=$variablename?> to print more concisely.
Re:PERL - the "Write-Only" language... (Score:4, Interesting)
good language for writing understandable code.
I was recently contacted by some people about a
web site full of cgi scripts that I wrote several
years ago. They sorta apoligized for not getting
back in touch, explaining that the code was so easy
to understand and modify that they just did it and
didn't need to contact me. But now they had some
more sophisticated needs that they weren't sure they
could program, so they thought they'd call back an
expert.
So maybe the lesson here is that I should learn to
write less readable code. Then people won't be able
to modify it themselves, and they'll have to hire
me to make trivial changes.
Re:PERL - the "Write-Only" language... (Score:5, Informative)
If you've had a bad experience with PERL, give Perl a try!
diff -c humor flamebait (Score:1)
I'm sure this one will be flamebait too, because some moderator won't get the "-c" joke.
Re:PERL - the "Write-Only" language...[HUMOR??] (Score:1, Interesting)
Perl allows you to do some really cool things, like fit 10-20 lines of code in any other language into 1 line of Perl. (Here [cmu.edu]'s the proof.) Of course, you pay the penalty for being "clever" 6 months down the road.
It's good to remember that just because you can do something, it doesn't mean you should do it.
Seriously though, if you've ever had to debug or maintain someone else's code, you should know how much trouble Perl can make for you. I'd almost rather debug assembly...almost. ;-)
Re:PERL - the "Write-Only" language... (Score:3, Interesting)
My personal favorite bit is the way you can suddenly create a new instance variable on a whim, just by assigning a value to $this->varName, halfway down a random function.
This, and I would think to say that all your piss-poor examples of why Perl is bad are cured with one statement:
Stop spreading FUD. I've seen and worked with many large, OO and non-OO Perl scripts which are a joy to maintain. You can get bad code in any language. Perl lets you shoot yourself in the foot if you want to. My personal preference is not to hire these types of programmers instead of complaining that the language is too flexible.
Re:PERL - the "Write-Only" language... (Score:2)
Come on, if you're going to flame me, at least make sense. I replied to a post about PHP, gave some PHP code examples as to why PHP is bad, and you've come back with that Perl users' mainstay: use strict;
I did read your post; I noticed that you had one reference to PHP in there, and I also took into account the subject line and came to the conclusion that you were knocking both Perl and PHP, as Perl has some of the same problems (creating variables out of thin air and silent conversion between incompatible types mainly) as PHP. It was a thought-out flame. Honest.
Re:Let me get this straight... (Score:2, Insightful)
So in your opinion, nobody is allowed to do anything while "The souls of the victims are watching"?
How are people supposed to move on from this tradgedy if they cant do anything to take their minds off it?
Anyway to get ON TOPIC, perl is a great language to write this sort of thing in. I prefer using Embedded Perl myself (i wonder how that would perform as an ecommerce solution.).
but perl IMHO is the most powerful and versatile CGI language around, java creates too much of a load, and C requires you to recompile after altering any of the code.
ok im rambling now..
Re:Scalability Myths (Score:2, Informative)
You're asking the wrong question (Score:2, Insightful)
They wrote a small piece in C++ because it was the right tool for the job. They wrote the rest in Perl because it was the right tool for the job.
If the whole thing was written in C++, they would probably still be coding the basic application.
When your needs are to get an application to market quickly, there are few languages that can compete with Perl.
If you question the scalability of Perl, I would challenge you to write a complex web application in any language that would handle 200,000 sessions and 2.5 million page views per hour.
Re:Scalability Myths (Score:2, Insightful)
Re:Not really enterprise architecture (Score:4, Informative)
Not true. There was a clean separation. The model objects didn't have any HTML or display code in them. The templates (views) had no control flow code, only formatting. The controller knew how to pick a view, but not what was in it.
What if eToys had survived the dot-com implosion, and bought or were bought by another company? How well would this system plug into (or be plugged into) any special-needs components of the new system? That's the real acid test of maintainability in the large.
We had well-defined and documented APIs for all of the components. The hard part in integrating with another system would have been the differences in core functionality, not the interfaces.
Maybe these standards exist for perl, and I haven't used it enough in an enterprise context to stumble across them. However, you can't help but stumble across the J2EE stuff when you work with Java. Are these standards perfect? No. Are they complete? No. But they're standards, and that's what makes pluggable components possible.
Only to the extent that you can move your J2EE app from one server to another. Every J2EE app uses the basic components (EJB, JSP, servlets, etc.) in its own way. You certainly can't just connect up your warehouse management code to someone else's shipping code without a thorough agreement on the interfaces. Expecting anything more than that is just dreaming.