Seva's notes

Wisdom, Awareness, Responsibility :)

Archive for February 2010

Is Facebook PHP HipHop bullshit?

with 17 comments

Update: with the release of HHVM 2.0 the below becomes entirely obsolete. Cheers!

Yes, it finally happened – Facebook announced the PHP to C++ translator. Hurray!
So, after reading the post I can assume it:

  1. parses PHP code,
  2. extracts PHP AST,
  3. converts to C++ AST and
  4. generates C++ code.

Honestly, it’s not the best way of optimization, but probably is a quick win (BTW, why did it take for them so long?), which theoretically might indeed generate efficient C++ code.

But wait, what do they report? “We’ve reduced the CPU usage on our Web servers on average by about1 fifty percent3, depending on the page2.”

I have some doubts:

  1. Where is the objective and comparative statistics?
  2. Did they even collect the general statistics, or just tested some pages to see the difference?
  3. 50%? That’s it? And how about the fact that C++ is actually 3-500 times faster (also here) (That would be 70% to 99% reduce of CPU). In fact the well known PHP Accelerators provide the same level of performance improvement as HipHop! It’s interesting, did they try any of them before entering the so called “Hackathon”.

In addition to reflections above, looking at the profiles of 2.5 coders which hacked the translator, I sorrowfully tend to estimate that the answer for the question in this Post’s subject is positive. Nevertheless I’m full of sincere hope that further info will dispel my suspects and prove that HipHop is actually a brilliant peace of software.

Written by Seva

2010-02-03 (February 3) at 02:05:49

Posted in development, integration, php, software, thought, web

Tagged with

FreeBSD MySQL MyISAM multi-CPU concurrency performance

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Recently we had a performance issue with multiple plain concurrent requests on a MyISAM table – the process list reported that all selects get stuck for very long time while Sending Data. After many tests we discovered that:

  1. The problem only occurs when running on multiple CPUs;
  2. The problem only occurs when running on FreeBSD OS.

After searching over the Internet we found, that this class of problems is being reported since antique versions of FreeBSD and, despite the claims it’s fixed with each version, it persists even in fresh 8.0.

So the decision was to install Linux on all the DB servers.

There is an alternative option though – it’s possible on FreeBSD to install MySQL of any version with WITH_LINUXTHREADS=yes parameter and it will be benefited from the Linux thread model.

Written by Seva

2010-02-02 (February 2) at 06:03:24

Posted in db, FreeBSD, hardware, integration, linux, software

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Download a Google Document with Zend_GData API

with 3 comments

Today I’ve thought of a way of showing a private Google Document on a custom page with no need to authenticate. I was surprised that the issue was not covered in any documentation; I also didn’t succeed to find a quick solution on the Internet. Thus I’m sharing with you the solution using Zend_GData library, my dear friend, with hope to save your valuable time:

$client = Zend_Gdata_ClientLogin::getHttpClient($user, $pass, Zend_Gdata_Docs::AUTH_SERVICE_NAME);
$api = new Zend_Gdata_Docs($client);
$doc = $api->getDocument($docId);
$client->setUri($doc->getContent()->getSrc());
$response = $client->request();
$html = $response->getBody();

Voila! The $html variable now contains the clean and image/css/js safe content to use (including <HTML> tags)

Note: The code lacks exception handling for simplicity, so please keep that in mind and fulfill upon need.

Written by Seva

2010-02-01 (February 1) at 06:35:51

Posted in development, integration, leisure, php, web, zend framework

Tagged with