Recent Updates Toggle Comment Threads | Keyboard Shortcuts

  • Jeff Forman 8:57 pm on February 8, 2013 Permalink  

    Wireless, now with more 802.11′s… 

    With nothing else to do around here tonight while the whole state is shut down thanks to a blizzard, I should catch up on some blog posts.

    On my list of home network upgrades for the past several months was the wireless. As my wife and I add to our collection of smart phones, laptops, tablets, and wireless streaming devices (I am looking at you EOL Logitech Revue with Google TV) the amount of latency and available bandwidth started to show signs of strain. I had been running the wireless for several years on an Asus WL-500G Premium v2 router/wap, which only ran 802.11b/g over 2.4Ghz. It was time for an upgrade.

    Welcome our new Asus RT-N66U 802.11b/g/n router/wap that handles dual channel 2.4Ghz and 5Ghz wifi.

    I did some very unscientific comparisons before and after I performed the hardware upgrade. I pushed and pulled a ~763MB Ubuntu ISO across the wireless, through a 10/100Mb switch, via rsync over SSH from a server on the LAN. The following table shows rsync’s average speed and transfer duration from the point of view of a 15″ Macbook Pro connected via the wifi.

    Old Wifi New Wifi 2.4Ghz New Wifi 5Ghz
    Upload  1.87MB/s (6:46)  7.69MB/s (1:39)  5.57MB/s (2:17)
    Download  2.61MB/s (4:51)  10.81MB/s (1:10)  10.39MB/s (1:13)

    Needless to say, I am keeping the new router.

     

  • Jeff Forman 2:01 pm on December 29, 2012 Permalink  

    California 2012, thricely. 

    Condensed version of trip #3 to California.

    San Diego

    • Sushi Ota: Sake and sushi with Mozilla folks. For the quality of the sushi (incredible), the price (reasonable) blew me away.
    • Tajima: Ramen! The spicy miso ramen here lives up to its name, be prepared.
    • Fish Market
    • Cucina Urbana: Serious Italian, and a wine list to match. Funky interior too.
    • Davanti Enoteca: Good tripe dish

    San Francisco

    • State Bird Provisions: Dim sum delivery, California style.
    • Black Point Cafe: Coffee refuel near the Golden Gate Bridge. Killer latte. Gary Danko
    • Spruce: The duck. Yes, get the duck.
    • Philz Coffee: No justification needed. Had to restock the East Coast supply.
    • Acqurello
    • Izakaya Roku: More ramen! Sake!
    • Humphry Slocombe: Blue Bottle Vietnamese Coffee Ice Cream. Good lord. I can now die a happy man.
    • Incanto: Charcuterie zen master.

    Napa/St Helena

    • White Rock Winery: We happened upon this one as they were dumping out the lower quality wine. So sad.
    • Oakville Grocery Co: Mid-Napa refuel. Bread, cheese, meats.
    • Saddleback Cellars
    • Gott’s Roadside: The juxtaposition of this in Napa is pretty jarring. Their milkshakes are a nice divider between all the wine.
    • Stag’s Leap Wine Cellars: This is where I cemented the fact that I like the smaller wineries, rather than the commercial behemoths.
    • Cliff Lede Winery
    • Morimoto Napa

    Central California Coast

    • La Bicyclette (Carmel): Pizza, charcuterie, cheese. Take out. To be returned.
    • Sierra Mar at Post Ranch Inn (Big Sur): One of the most spectacular sunset views on the Pacific Coast. Food is damn tasty too.
    • Big Sur Bakery: Brunch doesn’t start until 1030am, but the fruit strudel and latte’s are killer.
    • Dover Canyon Winery: Our first foray into Paso Robles wines. Unexpectedly awesome. Along with their 185 lb. St Bernard named Thunder.
    • Turley Winery
    • Whalebone: Free chili with every tasting. Clutch with all the damn rain.
    • Adelaide Winery
    • Olavino: Olive oil and salt, one made with ghost chili. Holy crap. and holy good.
    • L’Adventure Winery
     

  • Jeff Forman 5:29 pm on October 6, 2012 Permalink  

    Nagios and Git hooks, a redux 

    A while back I blogged about how I hooked up Nagios and Git to run the Nagios preflight checks before restarting with a new checkin’s worth of configs. But the more I looked at how it all fit together, the more I knew it could be improved. A sed hack, expecting a certain pattern in the nagios.cfg? Bad bad bad. Most of the improvement revolves around Nagios’s ability to reference relative paths for its config files. Given the path of the ‘main’ nagios.cfg file, you can then reference directories that contain your services, hosts, and other custom commands, in relation to that main file. With this functionality I significantly improved the Git->Nagios pipeline.

    First, the pre-receive hook

    #!/bin/bash
umask 022

while read OLD_SHA1 NEW_SHA1 REFNAME; do
  export GIT_WORK_TREE=/tmp/nagiostest-$NEW_SHA1
  mkdir -p $GIT_WORK_TREE
  /usr/bin/git checkout -f $NEW_SHA1
  sudo /usr/sbin/nagios3 -v $GIT_WORK_TREE/nagios.cfg
  if [ "$?" -ne "0" ]
  then
    echo "Nagios Preflight Failed"
    echo "See the above error, fix your config, and re-push to attempt to update Nagios."
    exit 1
  else
    echo "Nagios Preflight Passed"
    echo "Clearing temporary work directory."
    rm -rf $GIT_WORK_TREE
    exit 0
  fi
done

    Using the GIT_WORK_TREE environment variable, which specifies Git’s working directory, I check out the new set of potential configs to a temporary directory. This provides a temporary ‘waiting room’ for the proposed configuration to be tested, before before being put into production. Imagine never (intentionally) breaking Nagios again because of a broken host or service specification. The main thing remember is that all references in the nagios.cfg to other config files (hosts, commands, etc) must be relative paths. I.E., I have lines that look like “cfg_dir=configs” in the nagios.cfg. Note the lack of absolute paths. We now run the Nagios pre-flight check (nagios -v) on the nagios.cfg in the Git work tree. Depending upon the exit value of ‘nagios -v’, 0 for success and 1 for failure, we either proceed or die immediately. If success, clean up our temporary run directory.

    Now the post-receive hook:

    #!/bin/sh

echo "Updating repo /etc/nagios3"
sudo /usr/bin/update-gitrepo /etc/nagios3

    The post-receive hook merely runs a script, noted below, on the Nagios configuration directory.

    Update-gitrepo:

    #!/bin/sh
umask 022

REPO_DIR=$1
cd ${REPO_DIR}

/usr/bin/git pull origin master

    Given the Git checkout’s directory, we fetch the most recent push to the repository.

    For the final step we have to fix some permissions (given that my setup runs the repository through Gitolite as the git user). This hook is located in the actual checkout itself, /etc/nagios3, in the post-merge hook.

    #!/bin/sh

sudo chown -R nagios:admin /etc/nagios3
sudo /etc/init.d/nagios3 restart

    A full commit and restart looks like this:

    jforman@merlot:/mnt/raid1/personal/git/monitor/nagios/configs$ git push
Counting objects: 7, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (4/4), done.
Writing objects: 100% (4/4), 414 bytes, done.
Total 4 (delta 3), reused 0 (delta 0)
remote: Previous HEAD position was c80fa03... turn off test notifications with notifications_enabled 0
remote: HEAD is now at f088dbc... Example: Add boilerplate header that file is managed by Git.
remote: 
remote: Nagios Core 3.2.3
remote: Copyright (c) 2009-2010 Nagios Core Development Team and Community Contributors
remote: Copyright (c) 1999-2009 Ethan Galstad
remote: Last Modified: 10-03-2010
remote: License: GPL
remote: 
remote: Website: http://www.nagios.org
remote: Reading configuration data...
remote:    Read main config file okay...
remote: Processing object config file '/tmp/nagiostest-f088dbcebf194edbce78068b6004cbbfca703432/commands.cfg'...
remote: Processing object config directory '/etc/nagios-plugins/config'...
remote: Processing object config file '/etc/nagios-plugins/config/ftp.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/mail.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/snmp_int.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/nt.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/http.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/real.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/check_nrpe.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/snmp_storage.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/disk.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/mysql.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/snmp_load.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/fping.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/dhcp.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/ssh.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/rpc-nfs.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/mailq.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/breeze.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/dummy.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/netware.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/hppjd.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/load.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/mrtg.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/apt.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/snmp_cpfw.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/snmp.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/snmp_process.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/snmp_env.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/news.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/ntp.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/telnet.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/users.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/snmp_mem.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/procs.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/ifstatus.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/games.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/disk-smb.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/tcp_udp.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/snmp_win.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/ping.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/pgsql.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/ldap.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/flexlm.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/dns.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/radius.cfg'...
remote: Processing object config file '/etc/nagios-plugins/config/snmp_vrrp.cfg'...
remote: Processing object config directory '/tmp/nagiostest-f088dbcebf194edbce78068b6004cbbfca703432/configs'...
remote: Processing object config file '/tmp/nagiostest-f088dbcebf194edbce78068b6004cbbfca703432/configs/timeperiods.cfg'...
remote: Processing object config file '/tmp/nagiostest-f088dbcebf194edbce78068b6004cbbfca703432/configs/services.cfg'...
remote: Processing object config file '/tmp/nagiostest-f088dbcebf194edbce78068b6004cbbfca703432/configs/commands.cfg'...
remote: Processing object config file '/tmp/nagiostest-f088dbcebf194edbce78068b6004cbbfca703432/configs/hosts.cfg'...
remote: Processing object config file '/tmp/nagiostest-f088dbcebf194edbce78068b6004cbbfca703432/configs/abstracts.cfg'...
remote: Processing object config file '/tmp/nagiostest-f088dbcebf194edbce78068b6004cbbfca703432/configs/contacts.cfg'...
remote:    Read object config files okay...
remote: 
remote: Running pre-flight check on configuration data...
remote: 
remote: Checking services...
remote: 	Checked 95 services.
remote: Checking hosts...
remote: 	Checked 10 hosts.
remote: Checking host groups...
remote: 	Checked 7 host groups.
remote: Checking service groups...
remote: 	Checked 0 service groups.
remote: Checking contacts...
remote: 	Checked 3 contacts.
remote: Checking contact groups...
remote: 	Checked 2 contact groups.
remote: Checking service escalations...
remote: 	Checked 0 service escalations.
remote: Checking service dependencies...
remote: 	Checked 56 service dependencies.
remote: Checking host escalations...
remote: 	Checked 0 host escalations.
remote: Checking host dependencies...
remote: 	Checked 0 host dependencies.
remote: Checking commands...
remote: 	Checked 181 commands.
remote: Checking time periods...
remote: 	Checked 4 time periods.
remote: Checking for circular paths between hosts...
remote: Checking for circular host and service dependencies...
remote: Checking global event handlers...
remote: Checking obsessive compulsive processor commands...
remote: Checking misc settings...
remote: 
remote: Total Warnings: 0
remote: Total Errors:   0
remote: 
remote: Things look okay - No serious problems were detected during the pre-flight check
remote: Nagios Preflight Passed
remote: Clearing temporary work directory.
remote: Updating repo /etc/nagios3
remote: From monitor:nagios
remote:  * branch            master     -> FETCH_HEAD
remote: Updating c80fa03..f088dbc
remote: Fast-forward
remote:  configs/commands.cfg |    2 ++
remote:  1 file changed, 2 insertions(+)
remote:  * Restarting nagios3 monitoring daemon nagios3
remote: Waiting for nagios3 daemon to die..
remote:    ...done.
To git@monitor:nagios.git
   c80fa03..f088dbc  master -> master

    Note that I do keep the Nagios package bundled commands in the /etc/nagios-plugins directory and have purposely not put those in the Git tree. This allows for updated Nagios packages from Ubuntu to update those commands accordingly without interfering with the Git repo.

    Enjoy.

     

  • Jeff Forman 12:52 pm on March 24, 2012 Permalink  

    Remind Me: Damage done in San Francisco in six days 

    I am lucky enough to have a sister living out in San Francisco, and to be able to work out of our offices there. Below is a hit list of the places I ate at and visited in the span of six days. My stomach has finally recovered.

    Wineries (Sonoma County):

    Both of us are lucky enough to have been through Napa several times, so we decided to venture into Sonoma County. The last item in that list is an unsuspecting general store off of Dry Creek Road in Heldsburg which has an incredible sandwich list. This area turns Napa on its head, with a much more family-run low-key atmosphere. There is none of the pretense of visiting a large production winery such as Mondavi or the herds of people who visit Duckhorn.

    To Eat:

    I cannot recommend every one of these places enough. Izakaya Sozai serves killer ramen. Yank Sing serves dim sum on weekend mornings that melt in your mouth. Shuck your own oysters at Hog Island (we learned in about 30 seconds) at the farm while sitting on benches along Tomales Bay. Mission Chinese blasts gangster rap while you gorge yourself on craveable Chinese food.

    Go, eat, recover later.

     

  • Jeff Forman 2:44 pm on March 11, 2012 Permalink
    Tags: networking, smokeping   

    The Internet is slow. Is the Internet down? 

    We have all heard the same questions at one point in our careers, “Is the Internet down?” or “Getting to X site is slow.” You scramble to a browser to see if Google, ESPN or the NY Times websites are up. Then you fire up traceroute. In some cases, the pages might load slowly, in other cases not at all. These two situations are often downstream fallout of two connectivity issues: latency and packet loss. Latency is the time it takes for a packet to get from source to destination. The speed of light says the latency for one packet to get across the USA from New York to San Francisco is normally between 70-90ms [1]. Packet loss occurs when packets do not make it from their source to destination, being lost along the way. Many factors can contribute to packet loss, including overloaded routers and switches, service interruptions, and human error.

    When diagnosing network issues between source and destination, it is helpful to have data to backup your suspicions of slow and inconsistent network performance. Insert Smokeping.

    (More …)

     

← Older posts

c
compose new post
j
next post/next comment
k
previous post/previous comment
r
reply
e
edit
o
show/hide comments
t
go to top
l
go to login
h
show/hide help
shift + esc
cancel