dannyman.toldme.com


doodles, JIRA, Technical, Technology

TICKET. OR. GTFO.

Link: https://dannyman.toldme.com/2011/08/17/ticket-or-gtfo/

I do not know the provenance of the source material, and can make no claims of intellectual property rights here. TinEye finds 550 similar images.

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Photo-a-Day

Pretty Clouds

Link: https://dannyman.toldme.com/2011/08/24/pretty-clouds/

Rolled in early to the far side of campus for an All Hands meeting, and these clouds caught my eye.

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About Me, News and Reaction, Quotes, Technology

Steve Jobs

Link: https://dannyman.toldme.com/2011/08/25/steve-jobs-is-a-wise-man/

Personally, I am not fond of Apple products, but I can not help but admire Steve Jobs. I am enjoying a compendium of Steve Jobs quotes from the Wall Street Journal. This one hits close to home:

“The cure for Apple is not cost-cutting. The cure for Apple is to innovate its way out of its current predicament.”

I work for an Information Technology bellwether, which is both highly profitable and obsessive over maintaining its profit margins. Costs must always be contained. While we have a variety of interesting technology we are working to develop, we are presently completing our latest round of workforce reductions. I wish our leadership could be a little more like Steve Jobs:

“This is not a one-man show. What’s reinvigorating this company is two things: One, there’s a lot of really talented people in this company who listened to the world tell them they were losers for a couple of years, and some of them were on the verge of starting to believe it themselves. But they’re not losers. What they didn’t have was a good set of coaches, a good plan. A good senior management team. But they have that now.”

You know what John Chambers might say to that?

“The problem with the Internet startup craze isn’t that too many people are starting companies; it’s that too many people aren’t sticking with it. That’s somewhat understandable, because there are many moments that are filled with despair and agony, when you have to fire people and cancel things and deal with very difficult situations. That’s when you find out who you are and what your values are.”

Really, the whole collection is worth a read.

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Photo-a-Day

We Don’t Serve Pigeons Here

Link: https://dannyman.toldme.com/2011/08/27/we-dont-serve-pigeons-here/

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It is probably just as well

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Photo-a-Day

Morning Coffee

Link: https://dannyman.toldme.com/2011/08/28/morning-coffee/

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Maggie, content to sun on the porch, spares a moment to humor me by looking at the camera.

See also: Jessica Eats Breakfast

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About Me, Free Style, Photo-a-Day

Everyone Believes in Dogs

Link: https://dannyman.toldme.com/2011/08/29/everyone-believes-in-dogs/

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I have been writing most days at 750words.com.  This is a little like Sy Safransky’s Notebook, as published in The Sun Magazine.

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Photo-a-Day, Sundry

All Roads Lead to San Jose

Link: https://dannyman.toldme.com/2011/08/31/all-roads-lead-to-san-jose/

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Monday afternoon I biked down the Guadalupe trail past the airport to San Jose Diridon Caltrain and rode a comfy baby bullet home to Mountain View.

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Free Style, Photo-a-Day, Sundry

Weekend Inspiration

Link: https://dannyman.toldme.com/2011/09/01/weekend-inspiration/

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Weekends when the wife is not around I enjoy a visit to my favorite coffee shop.  On this occasion while one patron was transcribing musical notation another regular started to work on the math of an idea about solar power generation.

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Photo-a-Day

Maggie “Pencil Sketch”

Link: https://dannyman.toldme.com/2011/09/02/maggie-pencil-sketch/

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My camera is dead so it is all about the Android phone now.  This is Maggie, played with in PicSay Pro.

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Photo-a-Day

Lake Point Tower

Link: https://dannyman.toldme.com/2011/09/03/lake-point-tower/

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Lake Point Tower rising majestically from the trees.  Mei-Lin sais she thinks Oprah lives there, has four floors to herself.  She doesn’t like to feel crowded, I guess.

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Photo-a-Day

Bee at Millenium Park

Link: https://dannyman.toldme.com/2011/09/04/bee-at-millenium-park/

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There were a lot of these ladies at the park, and they were very busy.

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Photo-a-Day

American Airlines

Link: https://dannyman.toldme.com/2011/09/05/american-airlines/

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I am flying Virgin but this scene of silver-cylindered beauties struck my fancy.

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Linux, Technical

Latency Goggles for Linux

Link: https://dannyman.toldme.com/2011/09/09/netem-test-tcp-performance/

While diagnosing why an internal web site is slow for some users, I got data that our overseas colleagues see ping latency to the web site of around 200 ms. This is not unreasonable. Some web sites that attach a lot of additional objects cause remote clients to have to open several connections and make several round-trips to load and render a web page. What might work fine at 20 ms latency can really drag at 200 ms.

How to test this out? As a Linux user, I can use netem to induce added latency on my network interface:

# ping -qc 2 google.com
PING google.com (74.125.224.145) 56(84) bytes of data.

--- google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 5009ms
rtt min/avg/max/mdev = 4.136/4.197/4.258/0.061 ms
# tc qdisc add dev wlan0 root netem delay 200ms
# ping -qc 2 google.com
PING google.com (74.125.224.144) 56(84) bytes of data.

--- google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 5474ms
rtt min/avg/max/mdev = 205.006/205.034/205.062/0.028 ms

# tc qdisc change dev wlan0 root netem delay 0ms
# ping -qc 2 google.com
PING google.com (74.125.224.50) 56(84) bytes of data.

--- google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 5011ms
rtt min/avg/max/mdev = 4.117/4.182/4.248/0.092 ms

Note, I’m on wireless, so I’m tuning wlan0. you’ll want to hit eth0 or whatever is appropriate to your configuration.


The YSlow plugin or the Google Chrome Developer tool Network tab can be helpful to see what is going on:

Google Chrome's Developer Tool Network view without extra latency.

Google Chrome's Developer Tool Network view with extra 200ms latency.

So, with my web site, an added 200 ms latency doubles total page load time from 0.8 seconds to 1.6 seconds.

Here’s what I see when I visit the problem web site:

A problem web site at normal latency.

A problem web site at additional 200ms latency.

Total page load time at 7.5 seconds is nearly three times slower than without latency.


A very crude way to measure things is with wget on the command-line.

The wget man page mentions the -p (page requisites) option, then the author suggests wget -E -H -k -K -p <URL>. (You’ll need to RTFM yourself…) So I do:

$ cd /tmp
$ sudo tc qdisc change dev wlan0 root netem delay 0ms
$ time wget -q -E -H -k -K -p http://google.com

real	0m0.160s
user	0m0.010s
sys	0m0.000s
$ sudo tc qdisc change dev wlan0 root netem delay 200ms
$ time wget -q -E -H -k -K -p http://google.com

real	0m3.832s
user	0m0.010s
sys	0m0.000s

Of course, even with all those options, wget behaves very differently from a modern GUI web browser: there’s no caching, it doesn’t parse the DOM and it will blindly download requisites it doesn’t actually need. (Even a large font file found in a CSS comment.) And it does all its requests serially, whereas a modern GUI web browser will fetch several objects in parallel. And whatever web browser you use over a connection with induced latency is not going to replicate the experience of remote users pulling page requisites from zippy local CDNs.


At the end of the day, I proposed the following advice to my remote colleagues:

  1. Try tuning the web browser to use more concurrent TCP connections.
  2. Try modifying browser behavior: middle-click faster-loading sub-pages in to new tabs, work on those tabs, then refer back to the slower-loading “dashboard” screen, reloading only when needed.

I also tweaked the web application to make it possible to show a more lightweight “dashboard” screen with fewer objects hanging off of it. This seems to improve load time on that page about 50%.

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Photo-a-Day

9/11 Ceremony in Mountain View

Link: https://dannyman.toldme.com/2011/09/10/911-ceremony-in-mountain-view/

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Civis Center Plaza, 11am

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News and Reaction, Photo-a-Day, Sundry, Testimonials

9/11 Ceremony Mountain View, CA

Link: https://dannyman.toldme.com/2011/09/11/911-ceremony-mountain-view-ca/

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Tenth anniversary of the attacks.  A bit difficult to recite the Pledge of Allegiance with that knot that still forms in the back of the throat.

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