PHP vs node.js: The REAL statistics
The theory suggests that synchronous or blocking model of I/O works something like this:
I/O is typically the costliest part of a web transaction. When a request arrives to the apache web server, it passes it to PHP interpreter for scripting any dynamic contents. Now comes the tricky part - If the PHP script wants to read something from the disk/database or write to it, that is the slowest link in the chain. When you call PHP function file_get_contents(), the entire thread is blocked until the contents are retrieved! The server can't do anything until your script gets the file contents. Consider what happens when multiples of simultaneous requests are issued by different users to your server? They get queued, because no thread is available to do the job since they are all blocked in I/O!
Here comes the unique selling-point of node.js. Since node.js implements async I/O in almost all its functions, the server thread in the above scenario is freed as soon as the file retrieval function (fs.readFile) is called. Then, once the I/O completes, node calls a function (passed earlier by fs.readFile) along with the data parameters. In the meantime, that valuable thread can be used for serving some other request.
So thats the theory about it anyway. But I'm not someone who just accepts any new fad in the town just because it is hype and everyone uses it. Nope, I want to get under the covers and verify it for myself. I wanted to see whether this theory holds in actual practice or not.
1. Accept the request.
2. Generate a random string of 108 kilobytes.
3. Write the string to a file on the disk.
4. Read the contents back from disk.
5. Return the string back on the response stream.
This is the first script, index.php:
And here is the second script, server.js:
And then, I ran the apache benchmarking tool on both of them with 2000 requests (200 concurrent). When I saw the time stats of the result, I was astounded:
#PHP: Concurrency Level: 200 Time taken for tests: 574.796 seconds Complete requests: 2000 #node.js: Concurrency Level: 200 Time taken for tests: 41.887 seconds Complete requests: 2000
The truth is out. node.js was faster than PHP by more 14 times! These results are astonishing. It simply means that node.js IS going to be THE de-facto standard for writing performance driven apps in the upcoming future, there is no doubt about it!
Agreed that the nodejs ecosystem isn't that widely developed yet, and most node modules for things like db connectivity, network access, utilities, etc. are actively being developed. But still, after seeing these results, its a no-brainer. Any extra effort spent in developing node.js apps is more than worth it. PHP might be still having the "king of web" status, but with node.js in the town, I don't see that status staying for very long!
After reading some comments from the below section, I felt obliged to create a C#/mono version too. This, unfortunately, has turned out to be the slowest of the bunch (~40 secs for 1 request). Either the Task library in mono is terribly implemented, or there is something terribly wrong with my code. I'll fix it once I get some time and be back with my next post (maybe ASP.NET vs node.js vs PHP!).
As for C#/ASP.NET, this is the most optimum version that I could manage. It still lags behind both PHP and node.js and most of the issued requests just get dropped. (And yes, I've tested it on both Linux/Mono and Windows-Server-2012/IIS environments). Maybe ASP.NET is inherently slower, so I'll have to change the terms of this benchmark to take it into comparison: