关于PHP和Java的问题

Question

I want to know how Java (JSP) on Tomcat compares to PHP on Apache in terms of performance.

Two servers with the same hardware configurations, one running Tomcat/Java (JSP) the other Apache/PHP, both servers maxed out with how many connections they can handle at once. Would they be somewhat close or would one pull away from the other one by a large margin? I basically just want to know if Tomcat/Java (JSP) is going to be a big performance hit if I switch to it vs PHP. If anyone can give a detailed answer on why one is faster than the other that would be amazing. Links are great too, I was unable to find anything online surprisingly.

Please no Java vs PHP wars, this is about performance only, nothing to do with the languages themselves.

Note: If there is any other concerns I should have for switching to Java from PHP please let me know. I REALLY hate asking this question because I'm usually the first person to say "program in what you like" but in my situation I need whats also good for the projects I work for. I know that there are large sites written in JSP, but it doesn't mean that they're better.

Thanks

Answer 1

What's good for the projects you're working on is to spend as little time as possible to write them as developer time is way more expensive than any perceived differences in performance. So stick with what you're familiar with.

The answer to your question is: they are both fast enough.

Any such comparison is hard because you end up doing things differently in different languages. Java bytecode is probably faster to interpret but then again any decent PHP install uses as opcode cache largely negating any such advantage in real terms.

Java also has a more complicated development model because Web processes are persistent. This can have a performance advantage but also can create problems like memory and other resource leakage, which PHP doesn't tend to have because everything is created and destroyed on each request (barring session information, memcache and so on).

Also PHP extensions can be created for any parts that you want to speed up.

$10,000 can buy an awful lot of hardware. It can buy the hardware to run SO. It doesn't buy much developer time.

I've got experience doing both Java and PHP development. I will generally choose PHP for Web development because of:

• quicker to test changes in development (ie no build/deploy steps and Java hot-deploy has serious limitations). Words cannot express how freeing it is to test changes by saving the file you're working on and clicking reload on a browser vs running an Ant/Maven build process;
• far fewer issues of memory/resource leakage;
• extensive library of functions to do pretty much anything you want;
• cheaper to host (at the low end).

I will use Java for some things, like anything that involves a lot of background processing and threading, which aren't PHP's strong points.

You'll note that performance (or the lack thereof) doesn't even rate as a reason for or again.

Sorry if that doesn't answer your question, but such concerns over performance are a pointless distraction.

Answer 2

The best way to answer performance questions is with a benchmark. Implement some simple page in both PHP and Java and then benchmark them using ab (Apache Benchmark).

Having said that, I suspect Java will outperform PHP because of the nature of the 2 platforms. Java is compiled to optimized bytecode (once) and then interpreted by a virtual machine. When Tomcat runs, the JVM loads the classes required for any given page and keeps them in memory so they're ready to go when an HTTP request hits the web server. Contrast that with PHP which reloads and re-interprets the code from scratch with each invocation by Apache. This is helped to a large degree by op-code caching, but still not to the level of what happens in the JVM.