Limit number of php-cgi processes spawned by nginx

Here’s how to Mine was around here somewhere.

File was here

sudo nano /usr/bin/php-fastcgi

Original file looked something like this.

#!/bin/bash
/usr/bin/spawn-fcgi -a 127.0.0.1 -p 10005 -u www-data -g www-data -f /usr/bin/php-cgi

Added -C argument to enforce a limit.

#!/bin/bash
/usr/bin/spawn-fcgi -C 2 -a 127.0.0.1 -p 10005 -u www-data -g www-data -f /usr/bin/php-cgi

http://forum.slicehost.com/index.php?p=/discussion/3671/limit-number-of-php-cgi-processes-nginx/p1

I just got a notice from my VPS host that my box was using too much swap and therefore impacting other users on the machine. As such, my provider did a hard reset on my instance which summarily stopped my web app (I don’t start the app on startup. I should.)

I just upgraded my server a few versions up the Ubuntu chain because of the heartbleed SSL bug so obviously it was something related to the upgrade. I’m not super savvy with figuring out which components changed so I figured if I could just cut back on the memory usage things wouldn’t go to swap. My server is running an app and a couple of old Drupal blogs that don’t get much traffic but I like to keep around for nostalgia. So, I figured I could sacrifice substantial performance on the blogs.

Things I changed to hopefully save memory:
/etc/mysql/my.cnf
* reduce max_connections to 50 from Not specified.

/etc/php/cgi/php.ini
* reduce memory_limit from 128M to 64M

/usr/bin/php5-cgi
* add “-C” flag to constrain number of processes to 3. (default was 5)

The php5-cgi change by far had the largest affect because each php5-cgi process was using 25MB per thread (~125MB, or 50% of my 256MB VPS).

HTML Email: Image height is 1px high for Gmail in IE10

Lately I have had to redo some of the HTML emails. We had an outside contractor do most of the work and he did a fantastic job. However, I was noticing that under a very specific condition, the email images were not rendering properly in desktop Gmail on Internet Explorer 10. I have no idea how many people are using GMail+IE10 but since this is our first real contact with the user, I though it would be important to ensure the best user experience possible. Broken images are not a good experience.

Here is the problem:
Email image poorly rendered

Old HTML

<img class="imageScale" 
style="display: block; width: 550px; height:auto;" 
width="550" height="auto" src="{{ img_url }}" 
border="0" />

New HTML

<img class="imageScale" 
style="display: block; width: 550px;" src="{{ img_url }}" 
border="0" />

Final outcome:
email-good

Why does it fix it?

I came across a couple of quirks at play in this porblem.

First, I learned that GMail automatically converts CSS height attribute to min-height with reckless abandon.

Second, the original HTML IMG tags have height:auto. With GMail’s reckles height conversion it becomes min-height:auto which essentially means 0px or 1px.

To solve, I removed height attributes on the img tags. It turns out that all of the browsers will automatically just render the image at full size of the parent container. In this case we have a series of nested tables that set maximum width of the parent to about 550 and the minimum width is 100% of screen width.

Delete old iOS backups to reclaim disk space

source:apple.com

source:apple.com

Just yesterday Apple released a critical patch that fixes a major security flaw. That Mac OS update required 3GB free on my machine.  That’s trouble! I have an older MacBook Air with a 128GB hard drive so I’ve been hovering with under 2GB of available disk space for a long time.

Even after some aggressive spring cleaning of Applications and old file attachments I still did not have enough disk space for the Mac OS update. At this point it dawned on me that I had recently  used iTunes to setup a new iPad that I bought and all the apps autmatically synchronized onto the new iPad without downloading anything. All that data must be stored somewhere.

So, I had to find out where iTunes keeps its backups. A cursory Google search found Apple iOS Backups which reveals that iOS backup files are housed in ~/Application Support/MobileSync/Backup for Macs. Sure enough, my mobile backup folder had 4 subfolders hogging up 20GB(!) of disk space. Since we only have 2 iOS devices in the house it was clear that iTunes still had backups for an old iPhone 3GS that I had given to my mom.

The folders contain encrypted iOS backups so I didn’t know which folder corresponded to each of my devices. Consequently, you have to delete your unwanted iOS backups using iTunes. The instructions “Deleting a Backup in iTunes” show that you can delete backups in iTunes >Preferenes > Devices.

Clearing out the old iOS backups gave me back 10GB of hard drive space! I haven’t had this much free disk space since I bought this laptop 3 years ago.