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The Environmental Impact of PHP Compared To C++ On Facebook
Kensai7 writes "Recently, Facebook provided us with some information on their server park. They use about 30,000 servers, and not surprisingly, most of them are running PHP code to generate pages full of social info for their users. As they only say that 'the bulk' is running PHP, let's assume this to be 25,000 of the 30,000. If C++ would have been used instead of PHP, then 22,500 servers could be powered down (assuming a conservative ratio of 10 for the efficiency of C++ versus PHP code), or a reduction of 49,000 tons of CO2 per year. Of course, it is a bit unfair to isolate Facebook here. Their servers are only a tiny fraction of computers deployed world-wide that are interpreting PHP code."
What about all the cycles compiling and debugging C++ code? Or all the trees torn down for C++ books? Or the environmental impact of C++ developers? I mean, have you ever had to share a cube with one of them? Pheewww.
Run and catch, run and catch, the lamb is caught in the blackberry patch.
Seriously, is somebody taking seriously the 1 to 10 ratio of the story?
I mean, maybe raw execution of pure code is going 10 times slower in PHP than C++ (ouch, I didn't know that) but even then, it's far from representing the same ratio when talking about a number of servers. You have to take into account all other parameters (disk access, network, IO, etc... Those aren't 10 times as slow in PHP one would guess).
I would be astonished if this ratio is close to be the truth. Does anyone have any insight/information on this?
Write boring code, not shiny code!
What about the impact of whole classes of C++ bugs that don't exist in C++
I've spent many a sleepless night worrying about C++ bugs that don't exist in C++. I'm glad I'm not alone.
First posting isn't trolling. It's...first posting.
That's crazy. 10:1 is incredibly unfair. Especially when you consider that a cached C++ page takes just as much time to return as a cached PHP page. On top of that, majority of the work done is just searching a database. If would imagine a large part of processing a page is in getting and returning data, which is then up-to-the database. He is using stats that say PHP is 10 slower for running through loops, math that type of crap. Says nothing about querying a database then doing some minor presentation related logic. If I had to guess, for a web page the average "efficiency gain" of using C++ would be under 2x.
Just serve up plain text files. Anything else is pure decadence!
I'm thinking that these scripts are just thin front ends to a massive db. Thus, a lot of the computer's time is going to be spent on I/O, and a lot of the processing is going to be taking place in the db itself, which is probably written in C.
Mod points: Guaranteed to remove your sense of humor.
Side effects may include gullibility and temporary retardation
Simply put: no.
The reason why they have so many servers is because Facebook contains so much data. The servers are there for a reason, and the reason is CACHING.
The overhead of PHP is very small for a platform that is all about sharing data and the bulk of processor time surely goes towards fetching that data in the first place. What, do you seriously think that when you hit your home page on Facebook, there are database queries issued for that? Lulz.
Besides, I'm almost sure that FB uses something like Zend Accelerator, which increases code execution speed a lot.
Anyway, just no.
Why not rewrite everything in assembly? This comparison comes to a conclusion without any facts to back it up. As others have pointed out there is development time and compile time associated with C++... and what about ongoing development? Where does 10-1 come from? Are you assuming they aren't doing any optimization or using any sort of accelerator? I've personally re-written code in C++ from php, and then done the comparison. In our case, we decided the extra maintainability was worth the approx 10-20% increase in speed we saw.
> a PHP programmer who turns out good PHP code
Yeah, that'd be me. Hi! We do exist, and there are plenty of us.
Granted, we tend to be outnumbered 100:1 by the PHP programmers who produce complete crap. The same is probably true of nearly any language.
I use it because I can code up relatively fast, relatively secure dynamic websites in a very short amount of time. I can install it on a webserver in seconds and it integrates beautifully with Apache and MySQL. Maybe there is a better solution out there, but PHP has always done what I need it to and I've never had a problem with it. It's never given me a reason to look elsewhere.
What I don't understand is all of the PHP-haters out there. Really, who cares if it is "the script kiddie's substitute for cgi-perl"? Isn't the proper measure of a tool if it does what you need it to and not who else uses it?
"development" also has one.
Not to mention clients. 20K servers is nothing compared to the millions of clients drawing higher power due to running looping flash commercials.
What C++ has always lacked, and PHP, Java and others do not, is a bundle of standard libraries that let you do things like process XML, talk to databases, and make templating EASY.
That's it. php does the same things C++ does, but go one beyond and add a rich library and of course, the ability to skip the "compile" step in the write -> compile -> test
I agree with you, but there's one small thing I don't get.
Faced with this piece of information, someone thought the logical thing to do was to, er, write an entirely new language?
"even arp drags a server down when you have 20K+ connects"
Are you perhaps a server admin in my company? I swear this is the best excuse for poor performance I've ever heard.
It wouldn't be so popular in first place if it was worthless. I wonder how much CO2 would be released into the atmosphere by the cars and computers of all the extra coders necessary to develop in C++ a website that could otherwise be developed in PHP, in the same period of time and with all other things equal. This is the same tired argument that can be used against *any* interpreted language. I love C++ - it's my favorite programming language - but I always use PHP for website development and I'll go on using it unless I'm forced not to.
A self proclaimed good PHP programmer... yeah there are about a 100 of those to every 1 that doesn't do that.
"ever read someone's c++ code? has it been a good experience?"
Sure, when the code is written by someone who really knows how to use C++. Ever read bad PHP code? Bad Java code? I have seen programmers do things like this:
int int1, int2, int3, int4, int6, int7;
No, that is neither a joke nor an exaggeration, and the missing number is deliberate. This is a declaration I saw on a recent project. This kind of poor coding is language agnostic, and it is entirely irrelevant whether someone is using C++, PHP, or even a language like Haskell (bad Haskell code is worse than that worst C++ code I have ever seen -- if you use a functional language, get it right!).
On the other hand, I have seen some maintainable C++ code, with appropriate and useful comments, well thought out classes and class relationships, and expert use of the STL. I once worked on a project with C++ code that dated back to the early 90s, and had been continuous updated to support new features and needs, to make use of the STL (yes, this can be written into old code without causing a disaster), and so support systems that did not even exist when the code was originally written.
Don't blame the language, blame programmers who never learned about good programming practices. Blame computer science programs that give people degrees they do not deserve. Blame an industry that will hire anyone who can write a hello world program and then assume that they are capable of writing a maintainable system with millions of lines of code. The best programming language in the world will not solve the problem of poor programmers and poor coding practices.
Palm trees and 8
Actually, Facebook uses APC to compile and optimize the code in the shared memory so it doesn't have to be compiled over and over again.
There are other libraries for caching PHP functions on many different levels as well, and they're open source, for the most part. Some real bright minds from Facebook and other large PHP applications have contributed to them.
Bottom line: PHP is quite powerful and efficient when built and extended properly.
mod_php has never integrated into Apache nearly as deep as mod_perl did. That is, lower level Apache APIs are not exposed to PHP. Using mod_php is an acceptable replacement for CGIs, but mod_perl does a lot more than that. That means taking over the entire server life cycle handlers to the point where, in Apache2, you can implement (say) a Gopher server if you want.
mod_perl is not a hack. PHP, as a language and an API, very much is.
Not a typewriter
Your post is really annoying. Did you mean to be so obnoxious? And +5, Insightful. Come on, php isn't popular with slashdotters but whatever one calls reverse fanboyism it isn't cool either.
No, features that make web development "dead simple" are those that actually do something to make web development simpler...
Absolutely. And PHP does it. That's why it's so popular. There may be even more that can be done but if no popular language is doing it already that argument is kind of pointless.
You contradict yourself.
No he doesn't. You might not like scripting / dynamic languages but taking the best (or a good stab at taking the best) of scripting, C and perl can actually make some things more straight-forward. Need a regular expression? Used to function calls rather can syntactical regex? Need perl regex? preg_match.
Patently false. PHP has no dependency on Apache now, it originally used CGI, and continues to support CGI, FastCGI, and operation as a module in web servers other than Apache (such as IIS). The CGI startup overhead problem has many solutions, such as FastCGI, AJP, proxying, etc.
Patently missing the point. PHP and Apache go together so well it created the LAMP mindshare space.
But "not in-process" does not imply the use of CGI, and it does not imply the use of any system with long loading times. Furthermore, "in-process" is potentially insecure and can be less reliable - as all code runs in the same process.
Who cares? His point is startup cost which is generally higher for forks vs modules and you're just plain going to get more scalability compared to the traditional perl cgi forking method. Hence mod_perl.
Give me a break. You can dislike anything you want but why do you even bother when you don't have all the facts.
+5, Insightful. Dear me...
Selah.ca. Pause, and calmly think on that.