I've looked at this article- HipHop PHP (was Hyper PHP by Facebook)
However, recently come across this Facebook Speeds Development With “HipHop Virtual Machine”, A 60% Faster PHP Executor
Does anyone have details on this? Is it worth exploring for a PHP developer?
You can find the details in the article linked in the article you linked:
https://www.facebook.com/notes/facebook-engineering/the-hiphop-virtual-machine/10150415177928920
hphpc is in essence a traditional static compiler that converts PHP→AST→C++→x64. We have long been keenly aware of the limitations to static analysis imposed by such a dynamic language as PHP, not to mention the risks inherent in developing software with hphpi and deploying with hphpc. Our experiences with hphpc led us to start experimenting with dynamic translation to native machine code, also known as just-in-time (JIT) compilation. A dynamic translator can observe data types as the program executes, and generate type-specialized machine code.
The type-specialized machine code runs faster. Unless you are the size of FB, you do not need this. Use APC or memcached and more traditional approaches to scaling out.
The other answer about HPHPC is accurate... the performance boost is quite nice, but only if you actually need it enough that it's worth the extra complexity.
I'd suggest waiting a few weeks or even months before looking into HPHPVM. It's looking promising, but it's still in the very early stages as far as optimization and bug-fixing go. In the long run it'll probably end up being a great alternative to Zend, but right now the relatively small boost in performance (compared to, say, full translated/compiled HipHop) is likely not worth the extra complexity. That said, do check back in a few months.
Related
I know you can minify PHP, but I'm wondering if there is any point. PHP is an interpreted language so will run a little slower than a compiled language. My question is: would clients see a visible speed improvement in page loads and such if I were to minify my PHP?
Also, is there a way to compile PHP or something similar?
PHP is compiled into bytecode, which is then interpreted on top of something resembling a VM. Many other scripting languages follow the same general process, including Perl and Ruby. It's not really a traditional interpreted language like, say, BASIC.
There would be no effective speed increase if you attempted to "minify" the source. You would get a major increase by using a bytecode cache like APC.
Facebook introduced a compiler named HipHop that transforms PHP source into C++ code. Rasmus Lerdorf, one of the big PHP guys did a presentation for Digg earlier this year that covers the performance improvements given by HipHop. In short, it's not too much faster than optimizing code and using a bytecode cache. HipHop is overkill for the majority of users.
Facebook also recently unveiled HHVM, a new virtual machine based on their work making HipHop. It's still rather new and it's not clear if it will provide a major performance boost to the general public.
Just to make sure it's stated expressly, please read that presentation in full. It points out numerous ways to benchmark and profile code and identify bottlenecks using tools like xdebug and xhprof, also from Facebook.
2021 Update
HHVM diverged away from vanilla PHP a couple versions ago. PHP 7 and 8 bring a whole bunch of amazing performance improvements that have pretty much closed the gap. You now no longer need to do weird things to get better performance out of PHP!
Minifying PHP source code continues to be useless for performance reasons.
Forgo the idea of minifying PHP in favor of using an opcode cache, like PHP Accelerator, or APC.
Or something else like memcached
Yes there is one (non-technical) point.
Your hoster can spy your code on his server. If you minify and uglify it, it is for spys more difficult to steal your ideas.
One reason for minifying and uglifying php may be spy-protection. I think uglyfing code should one step in an automatic deployment.
With some rewriting (shorter variable names) you could save a few bytes of memory, but that's also seldomly significant.
However I do design some of my applications in a way that allows to concatenate include scripts together. With php -w it can be compacted significantly, adding a little speed gain for script startup. On an opcode-enabled server this however only saves a few file mtime checks.
This is less an answer than an advertisement. I'm been working on a PHP extension that translates Zend opcodes to run on a VM with static typing. It doesn't accelerate arbitrary PHP code. It does allow you to write code that run way faster than what regular PHP allows. The key here is static typing. On a modern CPU, a dynamic language eats branch misprediction penalty left and right. Fact that PHP arrays are hash tables also imposes high cost: lot of branch mispredictions, inefficient use of cache, poor memory prefetching, and no SIMD optimization whatsoever. Branch misprediction and cache misses in particular are achilles' heel for today's processors. My little VM sidesteps those problem by using static types and C array instead of hash table. The result ends up running roughly ten times faster. This is using bytecode interpretation. The extension can optionally compile a function through gcc. In that case, you get two to five times more speed.
Here's the link for anyone interested:
https://github.com/chung-leong/qb/wiki
Again, the extension is not a general PHP accelerator. You have to write code specific for it.
There are PHP compilers... see this previous question for a list; but (unless you're the size of Facebook or are targetting your application to run client-side) they're generally a lot more trouble than they're worth
Simple opcode caching will give you more benefit for the effort involved. Or profile your code to identify the bottlenecks, and then optimise it.
You don't need to minify PHP.
In order to get a better performance, install an Opcode cache; but the ideal solution would be to upgrade your PHP to the 5.5 version or above because the newer versions have an opcode cache by default called Zend Optimiser that is performing better than the other ones http://massivescale.blogspot.com/2013/06/php-55-zend-optimiser-opcache-vs-xcache.html.
The "point" is to make the file smaller, because smaller files load faster than bigger files. Also, removing whitespace will make parsing a tiny bit faster since those characters don't need to be parsed out.
Will it be noticeable? Almost never, unless the file is huge and there's a big difference in size.
I was surprised to learn today that PHP is used widely in high-traffic websites.
I always thought that PHP is not strong in terms of performance, being a dynamic, scripting language (e.g. compared to statically typed, compiled language like C/Java/C# etc.).
So how come it performs so well?
What you'll usually find is that it's not as slow as you think. The reason a lot of sites are slow is because the hosts are overloaded.
But one primary benefit of PHP over a compiled language is ease of maintenance. Because PHP is designed from the ground up for HTTP traffic, there's less to build than with most other compiled languages. Plus, merging in changes becomes easier as you don't need to recompile and restart the server (as you would with a compiled binary)...
I've done a considerable amount of benchmarks on both, and for anywhere under about 50k requests per second (based upon my numbers) there really isn't a significant gain to using a compiled binary (FastCGI). Sure, it's a little faster using compiled C, but unless you're talking Facebook level traffic, that's not really going to mean significant $$$. And it's definitely not going to offset the relatively rapid rate of development that PHP will afford in comparison to using C (which more than likely will require many times the code since it's not memory managed)...
PHP, if properly written can be quite scalable. The limiting factors are typically in your database engine. And that's going to be a common factor no matter what technology you use...
Java deployments in a big enterprise setting are a mess...fighting with builds and code that might not compile for the slightest little things. Also, PHP runs on a fairly simple setup server-wise, not the bulky code that is Weblogic (or others), so others are right in that it's low cost to develop and cheap to deploy on several different machines. It certainly didn't help that I was soured by working in a large, VERY inefficient corporate setting while doing Java....
I wouldn't say that PHP developers are cheaper per se (I make more now as a PHP developer than I did as a Java UI developer) but I do know that my last employer paid me for a not-insignificant amount of time spent configuring, deploying, compiling, etc that is not required in PHP. We're talking probably one day/week of related configuration fussing due to new branch roll outs or release-related configurations. So, the extra I'm paid now is made up for by a significant amount more code that I'm able to work through each week.
PHP is certainly being helped by the fact that MySQL and Postgres (to a smaller extent) have become so much more powerful. They're not directly linked, but having that as a common pairing just sweetens the deal for those making decisions.
It doesn't really perform "so well", just well enough to be used. Keep in mind, though, that Java and C#.NET are also run as bytecode inside a VM. PHP, with tools such as Zend Optimizer, can also skip the compilation step and run as bytecode.
PHP will not run as fast as native, compiled C code, but websites such as Facebook compile PHP to C++ to make it run faster (see HipHop-PHP).
Most websites have performance bottle necks when querying a database etc. The amount of time the script spends executing is usually small compared to this. Using things like libmemcached can help mitigate this.
Many sites started as low-traffic sites. Once you have your PHP website running and suddenly you have to handle much higher traffic, it's cheaper just to buy more servers than to rewrite your app from PHP to something else. Moreover there are tools that improve PHP performance.
Also note, that there are other factors: database, caching strategy which affect performance more than PHP itself.
It doesn't, which is why there are projects like HipHop, but dynamic languages are often faster to develop in, and hardware is cheaper than developers.
In my opinion the stateless nature of PHP is the most important factor to it's scalability. It's been a while since I've done any web work with Java/ASP.NET, but I recall that both technologies have a central application "engine" that all requests are piped through. That's great, because information and state can be shared between instances, and a lot of bootstrapping (reading configuration files, connecting to databases, etc) can be done once, and then shared among instances. It's bad though because that central "engine" itself becomes a bottleneck for the whole application.
The lack of a central engine in PHP also means scaling your application is usually a simple matter of adding another web server to your rig (although scaling the database along with it is more complicated). I imagine scaling a Java/ASP.NET application is a good deal more complicated, and they reach a saturation point where adding more hardware gives less of a boost each time.
Yesterday Facebook launched HipHop, a sourcecode-converter from php to c++. The set of php functions and constructions is more limited than in standard php.
Are the current popular php frameworks (ZF, CakePHP, symfony) compatible with HipHop? If not, which parts of these frameworks are not usable?
If I'm not mistaken, HipHop has not been released yet -- even the wiki page linked from the Facebook annoucement yesterday is not up yet.
So, it's going to be a bit hard to answer, right now.
I suppose it'll all depend on :
The features used by the Frameworks -- like already said here and there, stuff like eval is not supported by HipHop
The PHP extensions used by the Frameworks : only a couple of those have been ported by Facebook to HipHop.
Depending on the Frameworks and your specific needs, maybe/probably some subsets of the Frameworks you are using will be supported, even if not every available components... I suppose time will tell which ;-)
With at least ZF and Symfony being used for Enterprise level applications, chances are pretty good they will run with HipHop. If not now, then sooner or later. However, the question is not so much if they can run with these frameworks, but how your supporting IT architecture looks like.
HipHop is for scaling large multiserver high traffic sites like Facebook. In your regular web application, you will likely get no advantage out of it. Just continue to use memcache and APC.
See these related articles:
http://www.readwriteweb.com/archives/rasmus-lerdorf-php-hiphop-facebook.php
http://ilia.ws/archives/213-My-Thoughts-on-HipHop.html
http://terrychay.com/article/hiphop-for-faster-php.shtml
http://www.brandonsavage.net/hiphop-for-php-who-benefits-who-doesnt/
While I'm sure most of us are curious about what HipHop is going to be, I know it will not be a replacement for PHP - it's very much a niche product: unless you're running a large server farm then the performance benefits vs the maintenance costs just wouldn't justify it.
Perhaps it might be an interesting alternative to use encoded PHP for some people - but again this introduces even greater maintenance overheads. The only low-volume scenario where a compiled PHP would seem to make a lot of sense is for embedded devices (where the software exists to support the hardware and not vice versa) and for very high security installations (where its not a good idea to have a interpreter available).
It's far to early to be able to say what PHP software will work with it. However even once thats established, I'd want to see a solid commitment from any supplier that they were going to explicitly support HipHop in the future before I switched.
C.
I won't repeat what has already been said, I'll just add that as soon as HipHop is released you can count on the opensource community to submit patches for your favorite framework for increased compatibility with HipHop.
Also, one good way to test whether your favorite framework is compatible or not would be to launch the test suite using HPHPi (you then know where to concentrate your patching effort ;).
Searching for 'eval' gives a lot of false positives, as you get hits for the word "evaluate" in comments, or escapeValue if the search isn't case sensitive, etc.
If you search for 'eval(' in ZF 1.11 you'll find in once in Zend/Serializer/Adapter/PhpCode.php on line 59, in a method that unserializes stored PHP code. The method isn't a part of the MVC architecture, db component, and actually isn't used anywhere else in the framework (Zend_Serializer_Adapter_PhpCode isn't instantiated anywhere else in the code base).
So if eval breaks your ZF-Hip Hop app, don't use Zend_Serializer_Adapter_PhpCode, or eval in your consumer code.
Simple answer: I don't think it would.
Just saw this on hiphop page: https://github.com/facebook/hiphop-php/wiki/
"You keep coding in simpler PHP, then HipHop executes your source code in a semantically equivalent manner and sacrifices some rarely used features – such as eval() – in exchange for improved performance."
Did a search for 'eval' on ZF 1.9 and there are over 100 occurrences.
The news in the PHP world today is Facebook's HipHop, which:
HipHop for PHP isn't technically a compiler itself. Rather it is a source code transformer. HipHop programmatically transforms your PHP source code into highly optimized C++ and then uses g++ to compile it. HipHop executes the source code in a semantically equivalent manner and sacrifices some rarely used features — such as eval() — in exchange for improved performance. HipHop includes a code transformer, a reimplementation of PHP's runtime system, and a rewrite of many common PHP Extensions to take advantage of these performance optimizations.
My question is, what type of web applications is this actually useful for?
Seems like typical database-bound web apps may not be greatly served by this, but rarer CPU-bound apps would.
Web applications that do a lot of processing and/or use a lot of memory. Apparently this HipHop will reduce CPU usage by around 50% and also reduce memory usage (I didn't see how much the memory usage would be reduced by mentioned anywhere). This means that you should be able to serve the same number of requests with fewer servers.
An added benefit may be that there will be some basic type checking to ensure that the code is consistent before it is compiled. This should help to locate the type of bugs that PHP currently tends to ignore as a result of its weak type system.
The downside appears to be that it might not support some of PHP's more dynamic features such as eval (though arguably that's a positive too).
Well it "transforms" PHP into C++ to help performance of a largely scalable website.
So, HipHop is for when you have a website that you started at Harvard that you quickly grow into a billion dollar company and that people are making a movie about starring Justin Timberlake. When you have such a website and want to save CPU cycles, but don't want to rewrite your codebase, you use HipHop.
If you are just starting out, unless you are trapped on a desert island with only PHP programmers that refuse to learn a more scalable language, you don't use HipHop.
Running machine code over interpreted code is faster. This is useful in one sense, but also reduces the amount of machines you require, as each processor has less work to do.
This is good for a company like Facebook, in that they can cut the amount of machines they need.
In terms of why it's useful for them, they probably run a lot of sorting and indexing, on the large amounts of data they have.
This article:
http://terrychay.com/article/hiphop-for-faster-php.shtml
answers this question perfectly with its series of "if" statements.
You can think of it as some sort of compiler that takes in a bunch of .php files, and generate a bunch of c++ files for which you can then compile using g++ (Not sure if other compilers are supported). The resulting exe is your web application with a web server included. That means you could run the exe and you are good to go. The web server is based on libevent and supposedly pretty efficient.
Hip Hop is essentially pointless to everyone except Facebook and other gigantic PHP-based sites. I'm sure many people will jump on the bandwagon due to "it's fast" but how many PHP based apps use whole server farms?
Just because you are working on a social network site, doesn't mean you should consider using HH.
I am thinking of using a PHP framework called CodeIgniter.
One of the things I am interested in is its speed. I have, however, no way to find out how fast it is, and would rather not simply take the word of their website for it. Does anybody know how I can determine its speed myself, or can someone tell me of a site that can?
Code Igniter also has some built-in benchmarking tools:
http://codeigniter.com/user_guide/general/profiling.html
Yes, the problem is you have to build your application to profile it.
At work we had a couple of projects written outside which we load-tested before putting them on our main boxes. We were quite surprised to find critical performance problems with both; one was written in CakePHP and the other was written using Drupal. I don't think this highlights a problem with any framework or CMS other than the need to do profiling and load-testing on any site which is going to get significant traffic. In both cases it was what the developer had done, rather than the characteristics of the software platform, that caused the problem. For example, there was a recursive function call the developer had created in the Cake project which instantiated the entire Cake object every recursion and this would have taken out the server had it gone live under load.
In my opinion performance should not be a deciding factor in choosing a framework; the objective differences are likely to be marginal and the way you use it is likely to cause far more performance problems than the inherent performance of the framework.
I believe that to scale any PHP application to run under load, you will need an opcode cache and you'll need to write in intelligent content caching using something like memcached or whatever built-in caching your framework supports.
If your site is database-driven I would be very surprised if your bottleneck would be the application framework. "Fast" as in faster development is what I would worry about rather than "fast" as in speedy handling of requests. Significant optimization is better done by caching strategies and optimizing your database access.
Besides database access your own code will be where most of the time for each request is spent (and even that is usually not significant compared to database access), the framework will likely not be affecting the time spent on a request, unless it is really badly written.
It way be better to look for a framework which has good caching support (which Code Igniter may have, I don't know), that will almost always save you more time than the few milliseconds you could shave off the request handling by using a slightly faster framework.
Have a look at the Zend Framework too, it has the benefit of being PHP 5, whereas Code Igniter is still PHP 4, as I understand it. That may be an issue when it comes to speed, but in favor of which framework I don't know. Zend has good caching support and a database profiler that can help you find where your bottlenecks are.
i'd recommend testing it for yourself. use xdebug's profiler to create a cachegrind compatible file and webgrind to visualize the file.
that way you end up with very reliable information.
CodeIgniter is plenty fast for most projects. Some have posted here and if you Google, you will find that it compares favorably to other frameworks with respect to speed.
I would agree with another poster that performance is usually not a big concern when it comes to framework choice. The major frameworks all have sufficient performance for most projects.
I maintain a site that gets slammed a few times a year. Last year the development team rewrote the entire site using Codeigniter and we have had much luck in terms of performance. Additionally, the time it took to perform the rewrite was minimal as this framework is quite easy to work with. CakePHP in my opinion is also a good choice if you find that you don't like Codeigniter.
For CodeIgniter and other PHP frameworks, PHP Quick Profiler is very handy for benchmarking and measuring speed especially for database queries. You must check this out:
php-quick-profiler
It's very easy to install and provides an awesome GUI for examine different benchmarking tests.