Scaling:

32:40 Don’t put too much stuff in a single web server. Your site is getting busier and busier, the answer isn’t just to crank up the concurrent processes. … 4-6x number of cores in the machine, depending on memory.

SPL Data Structures:

48:40 We also have some new SPL data structures. Here as you pop things onto the stack, they’ll foreach in the right order.

Moving from mod_php to nginx:

50:22 .user.ini and path-specific ini settings. Set a TTL so they’re not read every time. There’s no mod_rewrite in php-fpm or nginx. That’s where you’re gonna have to learn a little bit of LUA and play with the nginx configuration format.

On data standards:

~1:18:00 Web apps these days should be UTF-8 and UTC. It’s the only sane choice.

On client skepticism of using PHP for a large site:

~1:30:00Other people have managed to do it. A big website is hard in every language. [...] It’s so much more than the front-end language. Every large site in the world ends up using dozens of technologies, hundreds for some of them, so it’s a matter of putting all these pieces together.

Other Takeaways

class Foo implements JsonSerializable{} // handle json_encode() on your object

Error reporting:

Setting error_reporting = -1 turns everything on.

SQLite:

You should never write a flat text file parser again. If you’re ever looking at doing that, use SQLite.

nice -n 19 ionice -c2 -n7

See also:

it’s getting to the point where I won’t even run ‘ls’ without equipping it with ionice, nice, setuidgid, softlimit and envdir. level 80 nerd

— Pinboard (@Pinboard) January 23, 2012

#!/bin/sh

# From /media/cryptofs/apps/usr/palm/applications/org.webosinternals.ubuntu-natty-chroot/bin

CHROOT=/media/ext3fs/ubuntu-natty-chroot

cp /etc/resolv.conf ${CHROOT}/etc/resolv.conf

mount --bind /dev ${CHROOT}/dev
mount --bind /dev/pts ${CHROOT}/dev/pts
mount --bind /proc ${CHROOT}/proc
mount --bind /sys ${CHROOT}/sys
mount --bind /tmp ${CHROOT}/tmp

chroot ${CHROOT} /bin/bash

umount ${CHROOT}/tmp
umount ${CHROOT}/sys
umount ${CHROOT}/proc
umount ${CHROOT}/dev/pts
umount ${CHROOT}/dev

Do you have a Twitter icon like this in your menu bar?

Using the default settings, the birdy turns blue when there’s a new tweet in your timeline. The problem is, there’s always a new tweet. Asking your Twitter client for timeline notifications is like letting Mail.app check for new messages every 5 minutes, or welcoming people to stick their head inside your door at all hours.

Diverting your attention means losing your momentum. An hour with 1 ten minute interruption is more productive than an hour with 10 one minute interruptions, so if you have to lose focus, make sure it’s happening for the right reasons.

My dual-screen setup involves a MacBook Pro and an external Acer flat panel, but despite my own preferences, I’ve kept the laptop screen as the primary to avoid a font rendering issue. For reasons that were unknown to me, iTerm 2 would display a nice, thick font when the laptop was the primary screen, but a very thin font when the Acer was primary. Switching the primary and relaunching iTerm would cause the thickness to change. I first experienced the issue in Mac OS X 10.6, and it persisted into Mac OS X 10.7. I’ve recycled the bug report-quality screenshot above as an example of the difference.

Some searching finally brought me to a resolution involving Mac OS X’s built-in font smoothing:

defaults -currentHost write -globalDomain AppleFontSmoothing -int 2

Thanks to Steve Kuo for the solution.

Planetary scientists say there are aspects to our planet and its evolution that are remarkably strange. In the first place there is Earth’s strong magnetic field. No one is exactly sure how it works, but it has something to do with the turbulent motion that occurs in the Earth’s liquid outer core and without it, we would be bombarded by harmful radiation from the Sun. Next there’s plate tectonics. We live on a planet that is constantly recycling its crust, limiting the amount of carbon dioxide escaping into the atmosphere — a natural way of controlling the greenhouse effect. Then there’s Jupiter-sized outer planets protecting the Earth from frequent large impacts. But the strangest thing of all is our big Moon. “As the Earth rotates, it wobbles on its axis like a child’s spinning top,” says Professor Monica Grady. ‘What the Moon does is dampen down that wobble and that helps to prevent extreme climate fluctuations’ — which would be detrimental to life. The moon’s tides have also made long swaths of earth’s coastline into areas of that are regularly shifted between dry and wet, providing a proving ground for early sea life to test the land for its suitability as a habitat. The “Rare Earth Hypothesis” is one solution to the Fermi Paradox (PDF) because, if Earth is uniquely special as an abode of life, ETI will necessarily be rare or even non-existent. And in the absence of verifiable alien contact, scientific opinion will forever remain split as to whether the Universe teems with life or we are alone in the inky blackness.

Source: Is the Earth Special?

You may observe files with the correct ownership (chown) and permissions (chmod u+rw) that are write-locked. In my experience, the files were editable with sudo, and modification via the Finder would prompt for an administrator password. In these situations, you may be dealing with additional file attributes.

Access Control Lists (ACLs)

Your file may have an ACL that prevents writing by the current user. To view ACLs for a file, issue ls -le. Use chmod to modify ACLs. Run chmod -N to remove the ACL.

File Flags

Running “Get Info…” on a file and checking “Locked” is functionally equivalent to running chflags uchg [file]. Show flags in directory listings using ls -lO. See also: SetFile.

Extended Attributes (metadata)

For good measure, we should also mention extended attributes. xattr modifies attributes (xattr -r -c to recursively remove), and ls -l@ will display attributes.

I don’t know of any specific metadata that would prevent file modification.

All Together, Now

adam@fsck:~:0$ mkdir /tmp/foo && cd /tmp/foo && touch bar
adam@fsck:/tmp/foo:0$ xattr -w com.sixohthree.test "o hai" bar
adam@fsck:/tmp/foo:0$ chmod +a 'everyone deny write,append,delete' bar
adam@fsck:/tmp/foo:0$ chflags uchg bar
adam@fsck:/tmp/foo:0$ ls -le@O
total 0
-rw-r--r--@ 1 adam  wheel  uchg 0 Dec  8 09:18 bar
        com.sixohthree.test     5
 0: group:everyone deny write,delete,append

The uchg flag will prevent all file modifications, including changing ACLs and extended attributes.

adam@fsck:/tmp/foo:0$ date >> bar
-bash: bar: Operation not permitted
adam@fsck:/tmp/foo:1$ chflags nouchg bar
adam@fsck:/tmp/foo:0$ date >> bar
-bash: bar: Operation not permitted
adam@fsck:/tmp/foo:1$ chmod -N bar
adam@fsck:/tmp/foo:0$ date >> bar
adam@fsck:/tmp/foo:0$