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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."
That's a ridiculous way to analyze it. What about the environmental impact of the extra time required to write the same functionality in C++? What about the impact of whole classes of C++ bugs that don't exist in C++ (and, perhaps, vice versa) with the downtime or security breaches resulting from them? Or a hundred other ways in which writing all that software in C++ would be different of which I can't think at the moment?
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!
The thing that this article fails to see, is that some languages aren't for everyone. A PHP programmer who turns out good PHP code isn't going to magically make the same level of code for C++. It also doesn't see that Facebook can't be down for longer than an hour at most, otherwise risk user outrage. After all, they have many, many, many users and for it to go down for a day would be akin to Google going down for a day or so. The difference being that if Google is down for a day, most users can use Yahoo, Bing, Live, WolframAlpha, etc. to search. Not every Facebook user has a MySpace.
Taxation is legalized theft, no more, no less.
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.
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
I know your being funny but you've got a good point. Developing and maintaining C++ code is not like developing and maintaining PHP script. Which of course is why we have PHP to begin with. It's designed for the web and ease of implementation. Sure C++ would be faster running but not necessarily more efficient in terms of dollars.
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.
Does the author seriously believe that Facebook isn't running some sort of PHP compiling/caching service, like APC or something similar?
It would be ridiculous for them NOT to be running something like that, which eliminates much of the advantage C++ would enjoy through being pre-compiled. While there still may be a reduction if Facebook were magically changed to precompiled C++ code, the reduction would be fairly minimal. In addition to that, you'd need to factor in the debugging and coding/compiling times, which would exceed the PHP times by an order of magnitude at least.
What a troll. Any point or argument based on assumptions is very weak. Here there are two: "..Let's assume this to be ..." and "...assuming a conservative ratio of 10...".
Don't make stuff up.
-Foredecker
Jibe!
"assuming a conservative ratio of 10 for the efficiency of C++ versus PHP code"
ARRRRRGGGGHHHHHHHHHHHHH
Why? On what evidence? I mean, I hate PHP as much as the next guy, but last time I wrote a web application platform in C++, I got to the end, analysed the result and went "Great, I've made the fast bit even faster. Now, about that database engine..."
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?
while true it ignores things like your comparing a simple search box, with millions of users who post multi megabyte files to their personal space for everyone to see. try it some day save a facebook user's page locally and see just how much data is coming down that pipe, on top of the scripts that are running.
Your comparing googles front door with facebooks entire company. Google probably has that many servers running web crawlers, and twice over again to store that massive database they use.
i thought once I was found, but it was only a dream.
"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?
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.
It probably is a valid excuse if you have 20,000 client machines connecting locally via ethernet from a B class subnet such that the arp tables on the server keep overflowing.
Of course if you, as a system administrator ever let such an environment be setup you probably are really good at excuses anyway.
Yes. I know the difference. C is an elegant if simple language, which is hard to program properly. C++ is an abomination that attempted to take the elegant, simple nature of C by bolting on spare body parts from dead object-oriented corpses, resulting in a language that is neither simple nor elegant, which is even harder to program properly.
See, I know the difference.
But if the point is to gain efficiency, why would you stop at C++? It's not a magical perfect balance of performance with elegance. C would give better performance than C++.
Sure, there's the non-OO tradeoff (though you could quite easily gain the benefits of OO, though not as elegantly as C++), and then you don't have to deal with fucking templates (which are really nice to program, but a bitch to clean up when someone else has fucked them up for you).
The premise of the article is stupid, and shows a pure lack of understanding of PHP, web service architecture and implementation, and a not-inconsiderable dose of C++ fanboi-ism.
Microsoft is to software what Budweiser is to beer.
"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
Maybe you should learn the language first. It seems there are an awful lot of people who love to comment on the complexity and performance of C++, who never bothered to really learn the language. Yet this doesn't stop them from pretending the be experts on it.
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
This is idiotic, and is typical of the kind of pseudo-science underlying much of the climate alarmism currently en vogue. Like a lot of things, it is pretty much impossible to quantify which language ultimately uses more power, because of all the variables. As others have pointed out, you might save some power in the deployment of the code, but you would surely use more power in the development of that code. Then, you have to figure out what the total impact of that is, since you'd have more man-hours of coding, using human coders, who sit at desks, in offices, which must be heated and cooled, etc., etc.
Their decision for using PHP might have to do with being able to get their business up and running now using PHP rather than envisaging go-live a few years down the road with their developer resources and learning curve adjusted to C++ (which in all its well-deserved glory does take its time to master). Probably C's savings in power don't outweigh PHP's savings in manpower.
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.
Running a server is cheap.
Paying a developer is not.
Civilisation is largely about the multiplication of human effort through the consumption of energy and automation. So, we multiply this developer's effort by a couple of thousand when running one machine and then do the same on another several hundred machines beyond. Each costs several thousand dollars to purchase and several thousand more every year in electricity, in cooling, networking, management and maintenance.
So, the effects of developer incompetence are also multiplied several thousand times often across hundreds or thousands of systems. Millions if we're really lucky.
So it isn't just one server, it's just one extra datacenter. It often pays to hire better people.
running a server for a day - $1
You think you get a real server for that? You get a tiny division of a server for that kind of money.
2) why doesn't these big server farms start looking at migrating code from PHP to C or C++ when the PHP+web design is solid?
The network effect. They migrate to Java instead.
Speed to delivery is nearly always primary importance.
Indicating speculative projects and disposable code.
Deleted