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Premature Optimization with Ilia Alshanetsky @ Dutch PHP Conference | Notes

Georgiana — Fri, 11 Jun 2010 11:33:21 +0000

-> demonstrate the user concept with an imperfect solution that does the job, optimize along the way
-> tune the right portions of the application, not over-engineer from the very beginning
—> scale the scope to the nature of the problem

-> simplify
—> less code does not mean that it’s faster
—> PHP doubled the # of LOC in a few years but it’s faster, not slower

-> hardware [HW]
—> since it’s cheaper, maybe throwing HW at it this might get it faster & buy you time to find the solution to the problem
—> SW development time to optimize might be more expensive
—> CPU bottlenecks & RAM issues are easier to solve lately
—> drives, the well-known bottleneck, have also received SSD [measurements show it's a lot better]

-> HW caveat
—> might only temporarily solve issues
—> DB saturation
—> non-scalable code [this is NOT the same as high-performing code]
—> network bottlenecks [latency]
—> extremely low # of sessions per server [Smarty: 50 reqs/sec]

-> optimization
—> start by trying to make the code faster without modifying a LOC [this way you avoid introducing new bugs & QA cycle, easier deployment]

-> how PHP works in 30 secs
—> each require/include triggers compile+execute
—> compilation is expensive
—> opcode cache [if the file is not changed, you get it from the cache]
—> APC vs Zend’s solution vs X-Cache

-> in-memory cache
—> do the PHP sessions in memcache instead of filesystem

-> ways of caching data
—> complete page [caching proxy, e.g. Squid; pre-generate; on-demand]
—> cache the parts that are really slowing down the page [example using memcache for SQL results caching]
—> partial caching of code [example using memcache for results of a function call; cache TTL of 1h]

-> output buffering
—> Apache’s SendBufferSize should be the same as PageSize
—> tcp_wmem | affects everything on tcp-ip
—> tcp_mem |

-> use profiling to understand the real bottleneck in the code, without the “educated assumptions”
—> Xdebug & XHProf [last one comes from Facebook]
—> Kcachegrind

-> code that generates notices / errors is slowed down by them, because resources are allocated for them, even if you don’t see them

IE6 no more

Georgiana — Wed, 05 Aug 2009 18:21:11 +0000

When people unite in order to achieve a goal, things are possible. IE6 is eating up our development time much more than it should. Moreover, it’s counter productive to keep a website’s functionality list short just because less than 20% of its users are using ancient browser.

Let’s support the IE6 no more initiative by including code like this on our websites:

Ubuntu 9.04 (codenamed Jaunty Jackalope) announced

Georgiana — Wed, 22 Apr 2009 09:49:45 +0000

Tomorrow a new Ubuntu version will be released, 9.04. From the announced features, the ones I like most is the shipment of OpenOffice 3 (finally!) and a lot of feature enhancements to improve the user experience. The release nots are here.

Wayback Machine data center storing 85 billion web pages since 1996

Georgiana — Fri, 20 Mar 2009 21:16:01 +0000

ComputerWorld article.

Oh boy, make sure you write maintenable code

Georgiana — Wed, 18 Feb 2009 14:08:24 +0000

It’s a nice story, just never ever do this.

Form submit from JavaScript

Georgiana — Fri, 16 Jan 2009 13:50:52 +0000

Be careful: if you want to submit a form from Javascript using something like

this.form.submit();

document.forms[ myFormName ].submit();

and it gives you a nasty error like

submit is not a function

don’t despair, just:

look at the HTML source code:
change the name of the button to something else, like:

That’s all!

Now the explanation: the browser confuses your submit(); call with the button object, which has no such action.

The browser acted just like you were explicitly calling

button = document.getElementById( 'submit' );
button.submit();

Yahoo announces to anonymize data after 90 days

Georgiana — Wed, 17 Dec 2008 18:39:53 +0000

Yahoo! annnounces that all data collected will be anonymized after 3 months, from current 13 months. This is one of the first successful hits to Google, which “needs” data for 9 months, after cutting the previous period in two this September.

In our world of customized online services, responsible use of data is critical to establishing and maintaining user trust. [...] We know that our users expect relevant and compelling content and advertising when they visit Yahoo!, but they also want assurances that we are focused on protecting their privacy.

Anne Toth, Vice President of Policy and Head of Privacy.

It is mandatory that such companies respect our right to browse the internet as anonymous as possible, while using their services. There are better (but definitely more expensive) methods out there to make search results better.

Firefox 3.1 beta 1 released

Georgiana — Fri, 05 Dec 2008 10:36:41 +0000

A new version of the popular browser can now be used. Nice features have been added, we should see what’s in for the stability, though.

WordPress for iPhone

Georgiana — Mon, 08 Sep 2008 14:27:51 +0000

Mobility is more a requirement than an option nowadays. Meet the new WordPress for iPhone.

Google Chrome: A new browser enters the battle

Georgiana — Wed, 03 Sep 2008 20:09:55 +0000

After many years of dominance from Microsoft’s Internet Explorer, after Mozilla Firefox becaming our second nature, with interesting interface solutions from Safari, Google decides to enter the battle with the all-new Chrome. It’s not easy this time, but I think the tekkie world will quickly adopt it. It easily passes the ACID2 test and gets 78 out of 100 for ACID3. So for us developers it looks like they are on the right path, learning from others’ mistakes.

Like Firefox managed to eat slowly from IE’s slice for some time now by doing right the things that were frustrating and annoying users, Google is determined to fight using the same tactics.

So, people use Mozilla because it has many plugins? Yes, but it eats up your memory, so Chrome has a new approach isolating each tab as a separate process and giving you freedom of navigation.
Developers love the Firebug extension and can’t imagine working without it? Chrome gives us “inspect element” option in the contextual page menu.
Browsers timidly tried to suggest things while you were typing in the address bar? Chrome is all too Google-ish in this respect… just try it!
People are afraid of using yet-another-application for browsing the web because they use keyboard shortcuts? Just try the regular CTRL + F, CTRL + H or CTRL + J. Ah, and of course your Mozilla saved passwords, bookmarks and other stuff is offered to you during install. Can it get any better?

All the things which frustrated the guys are now attempting to get solved. They’re at least trying. Of course it’s beta and there are no things like mouse gestures yet, but the Google approach is different; they build early, launch soon. They offer the solutionto some problems and continue building upon it, and that’s what really makes the difference.

If you like watching all the features and architectural decisions in a non-conventional way, try the comic book. These guys just don’t market the usual way.