Below you will find pages that utilize the taxonomy term “linux”
February 15, 2014
Lessons learned tuning TCP and Nginx in EC2 at Chartbeat
I wrote a couple blog posts for work diving into what we learned optimizing our performance in EC2.
You can read both parts over at
http://engineering.chartbeat.com/2014/01/02/part-1-lessons-learned-tuning-tcp-and-nginx-in-ec2/
and
http://engineering.chartbeat.com/2014/02/12/part-2-lessons-learned-tuning-tcp-and-nginx-in-ec2/
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October 12, 2011
NRPE returning no output?
command[check_recent_core]=PLUGINPATH/check_recent_core.sh --file="$ARG1" --freshness=$ARG2$
Spot the error? I only wasted an hour of my life and another 30 minutes of co-workers trying to figure out why I kept getting a "NRPE: No output returned from plugin" error in Nagios. The issue? $ARG1 is missing a closing “$”. *slams head on desk*
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December 28, 2010
Determining my most used focal length in photos with python and dcraw
For the holidays I got a new Canon 7D camera. I’ve been saving quite a few amazon gift cards over the last year that I was previously planning on using towards purchasing the camera but thankfully Santa delivered me one. My current lens collection consists of
10-22mm f/3.5-4.5 70-200mm f/4 50mm f/1.8 18-55mm f/3.5-5.6 (kit lens) The lens collection has been built over the last 4 years from when I first got my Canon Rebel XT and I’ve been fairly happy with them thus far.
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September 26, 2010
Python pip on Ubuntu Lucid Lynx
Lately I’ve been reading up on Django a bit in an effort to get back into programming. It seems the preferred way of running Django is inside a virtualenv environment. I try to stick to packages when possible for installing applications and saw that the python-virtualenv package wasn’t too far behind at version 1.4.5, where the latest is at 1.5.1. This appeared at first to suit me just fine until I discovered the version of pip that gets installed along with python-virtualenv is at 0.
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August 14, 2010
Configuring Varnish
At $WORK I’m currently working on deploying a pool of Varnish servers to sit in front of some Apache servers running Pressflow. On our current infrastructure we’ve been running Squid for the past few years with very good success , minus a hiccup or two along the way, one involving memory fragmentation (thank you tcmalloc). Varnish has a few nice features that Squid lacks.
The ability to PURGE objects using wildcards
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June 5, 2010
Thinkpad Trackpoint sensitivity on Ubuntu
A while back I found some notes on configuring the sensitivity of my trackpoint on my Thinkpad T43 and took the time to tweak the values to get it just right. The commands were
/bin/echo -n 171 > /sys/devices/platform/i8042/serio1/serio2/sensitivity /bin/echo -n 119 > /sys/devices/platform/i8042/serio1/serio2/speed In order to keep those values the same on reboot, I placed those commands in /etc/rc.local. I rebooted and… values got reset. After struggling a bit and just giving up on the issue, I ended up just making a shell script that I would execute on boot each time (crappy solution).
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May 26, 2010
Check for missing reverse DNS entries on network
A quick way to check your network for IPs missing reverse DNS entries….
nmap -PE -sP 10.0.0.0/24 | awk '{if ($2 ~ /^[[:digit:]]/ ) print $2}'
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February 15, 2010
Support for authorized-keys.d/
Why is there no subdir inside .ssh called authorized-keys.d where I can just throw my ssh keys and easily manage them by file name instead of having to edit the authorized-keys(2) file?
I need to do some googling on this , a quick search yields this debian bug report on wishing for support for one.
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January 12, 2010
Windows 7 64bit + iPhone sync
I somehow attract issues whenever I build a new computer or do a fresh installation on my desktop. I currently dual boot between Windows XP 64bit and Ubuntu 9.10 (Karmic) which has served me well the last 3 years. My current setup is running atop a fakeraid mirror which at the time, was a PITA to get configured as it involved using a live cd and following a really long howto while crossing my fingers it would work.
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October 4, 2009
Reserved block space
Normally when a partition fills up, you remove some files, freeing up some space and watch your disk usage drop in
df -h The first time recently I ran into a situation where that wasn’t the case. I had filled up my root partition and after removing some files and moving some others to another partition I noticed no change in my output of
df -h Applications were crashing since they couldn’t write to the partition but I knew I had removed at least a few GB’s worth of data.
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October 1, 2009
Online backup solution for Linux
The past couple of weeks I’ve begun looking into an online backup solution as I start to realize I’d be really really really pissed if something happened to my data. Currently I’m running my desktop in a RAID 1 configuration using dmraid aka fakeraid, under Ubuntu Jaunty 9.04. The reason I ended up having to use fakeraid was because I still dualboot Windows XP 64bit for doing photoshop work and the occasional game play.
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March 2, 2009
Word of advice
Don’t run Windows 2003 on Xen (open source version). That is all. Thank you
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February 24, 2009
Command of the Day
ssh-copy-id , I hate myself for only finding out about this command 2 days ago and painlessly copying my ssh key to hosts in such a crappy manual method. I’m embarrassed I didn’t even bother scripting the process before finding out about this command.
From man page:
ssh-copy-id: install your public key in a remote machine's authorized_keys
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October 28, 2008
smokeping’s whacky source
I’ll first start off by saying I think smokeping is a great program and Tobi Oetiker is a great programmer whose contributions to the community have been great and in no way could I ever create MRTG or RRDTool. But…. After downloading the source to smokeping today and trying to configure it to run, I was completely shocked at how poorly it was put together. It’s clear that Tobi did not bother with making his code easy to run on any other system but his own with constant absolute paths to his own home directories on his personal machine!
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July 23, 2008
BIND zone file management
Anyone out there have any recommendations for managing zone files in BIND? It seems the general consensus is that people just end up using home grown systems. A lot of the web based projects out there are either abadoned or use strictly a database backend which is nice but it adds another layer of complexity, and a failure point. I’d like to be able to switch back and forth between using the management system and being able to do an inline search and replace if need be , on my zone files.
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March 3, 2008
Should have done this a while ago…
Added to .bash_aliases the following
alias confgrep='egrep -v "^$|^#"' I find myself too often going through massive config files and only wanting to see what is actually in the config, instead of weeding through a massive amount of whitespace and commented out documentation. I think squid.conf is probably the worst offender of this and the default snmpd.conf has a good amount of spew in it as well. Literally all of squids documentation is located in it’s configuration file, while it is somewhat useful, it’s usually just means a bigger PITA to find what you are looking for.
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March 2, 2008
Inline Search and Replace
I was going through some old code tonight from college that had my student id(SS #) in it and I wanted to strip out my SS # from it. I run into this situation a lot where I need to do a mass inline search and replace. I hope this command is useful to anyone else
find . -type f -exec sed -i 's/MyIdentity//' {} \;
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