Web Tortoise


Don’t Forget About Availability


Hello! This #WebTortoise post was written 2013-MAY-16 at 11:34 AM ET (about #WebTortoise).

Main Points

#- Analyze Availability by various Dimensions, e.g. Hour of Day or Minute of Hour, to look for patterns.

#- Performance infers Availability. Performance may be measured if and only if Availability = 1 (your choices are either 1 or 0; either something’s available or something’s not available).

#- We monitor Availability; we measure Performance.

#- Don’t go it alone. When working to uncover patterns in your Availability and Performance data, will need the help of others in the Organization.


I thought I’d break away from the normal second-and-third-person writing style of Webtortoise to write this more intimate, first-person post. Lately, I’ve been feeling bad for my buddy, Availability (In this Webtortoise Story, my buddy’s name is, “Availability”). You see, Availability’s cousin, Performance, has been getting all of the limelight. I mean, don’t get me wrong, Performance IS sleek and sexy while Availability IS binary and boring, but the only reason we’re able to talk about all these advancements in Performance is because of their JOINT efforts!

So much attention has been given to Performance lately that I am seeing more and more folks forget, or casually glaze over, Availability! The problem here is: Performance _infers_ Availability. That is, if it’s not available, then you cannot measure it [for Performance].

So please, help me spread the word and remind folks to never forget about their ol’ buddy and friend, “Availability”.

And now, your obligatory Webtortoise chart:

In this chart, we counted the number of Availability strikes (a.k.a. errors) for several days. Then we plotted the COUNT by Minute of Hour.

In this first chart, there is no special formatting. But can still see some high errors counts.

Blog Post Availability by Minute of Hour - 1

In this second chart, have highlighted and called out the discovered pattern! At first, the guessed pattern was incorrect because was trying to find a *single*. However, after pulling in some more people resources, was able to figure out there were *multiples*.

Blog Post Availability by Minute of Hour - 2

In this specific case, these patterns were caused by *two separate* log shippings, across two different subsystems, affecting page load (i.e. the page was not available)! And had it not been for a Performance Management Program, may never have discovered these Patterns!

Document Complete / OnLoad:

_The following is optional reading material._

LinkedIn: http://www.linkedin.com/in/leovasiliou

Twitter: @LvasiLiou

Download Excel sheet here:  https://docs.google.com/file/d/0B9n5Sarv4oonTjR0Zk9oYzI1bGc/edit?usp=sharing

#CatchpointUser #KeynoteUser #Webtortoise #Performance #WebPerformance #SiteSpeed #ChartsAndDimensions #Availability


Why Did The Statistician Cross the Road


Hello! This #WebTortoise post was written 2013-APR-30 at 09:35 AM ET (about #WebTortoise).

Main Points

#- Here’s to the statisticians of the world!


– Why did the statistician cross the road?
— He wasn’t sure.

– A statistician can have his head in an oven and his feet in ice, and he will say that on the average he feels fine (http://math.bnu.edu.cn/~chj/Statjokes.htm).

– A new government 10 year survey costing $3,000,000,000 revealed 3/4 of the people in America make up 75% of the population (http://www.ahajokes.com/m027.html).

– According to recent surveys, 51% of the people are in the majority (http://www.ahajokes.com/m027.html).

– Statistics play an important role in genetics. For instance, statistics prove that numbers of offspring is an inherited trait. If your parents didn’t have any kids, odds are you won’t either (One passed by Gary Ramseyer, taken from http://stats.stackexchange.com/questions/1337/statistics-jokes).

– Final Exam: A statistics major was completely hung over the day of his final exam. It was a true/false test, so he decided to flip a coin for the answers. The statistics professor watched the student the entire two hours as he was flipping the coin… writing the answer… flipping the coin… writing the answer. At the end of the two hours, everyone else had left the final except for the one student. The professor walks up to his desk and interrupts the student, saying, “Listen, I have seen that you did not study for this statistics test, you didn’t even open the exam. If you are just flipping a coin for your answer, what is taking you so long?”
The student replies bitterly (as he is still flipping the coin), “Shhh! I am checking my answers!” (http://math.bnu.edu.cn/~chj/Statjokes.htm)

– Statistics are like a bikini. What they reveal is suggestive, but what they conceal is vital (Aaron Levenstein, taken from http://www.workjoke.com/statisticians-jokes.html).

Document Complete / OnLoad:

_The following is optional reading material._

LinkedIn: http://www.linkedin.com/in/leovasiliou

Twitter: @LvasiLiou

#CatchpointUser #KeynoteUser #Webtortoise #Performance #WebPerformance #SiteSpeed #ChartsAndDimensions



RUM Charts Side-by-Side With Synthetic Charts


Hello! This #WebTortoise post was written 2013-FEB-28 at 06:15 PM ET (about #WebTortoise).

Main Points

#- Consider the instrumentation of different Performance measurement tools before looking at their respective measurement data.

#- Measure web assets (e.g. websites, pages and/or apps) as an output of many different inputs (In Webtortoise World, we are talking about Real User Measurements (“RUM”) and Synthetic Measurements). Use these external, outside-in measurements to complement what is done internally.

#- The Response Times of the different Performance measurements are relative to a number of factors (e.g. distance, geography, browser cache, versions, infrastructure, application, ISP, CDN). These factors may also be different for each web asset.

#- See ‘Arithmetic Mean’ versus ‘Geometric Mean’ versus ‘Median’


In this Webtortoise post, will be looked at the various Response Times of the Ask.com homepage (Thank you, Ask.com). Have chosen this page because:

01. The URL http://www.ask.com/ was easy enough to measure Synthetically and RUMally (is that a word?) ;

02. It has a good mix of both first-party and third-party asset/object calls ; and

03. It has a good mix of both cacheable and non-cacheable asset/object calls.

Screenshot of the Ask.com homepage (2012-DEC-05):

Ask Home Page

In this post, the RUM data comes from Google Analytics and the Synthetic data comes from Catchpoint (thank you Google and Catchpoint). The RUM settings have been filtered to Geography=United States and Browser=Internet Explorer. Have also taken the metric ‘names’ directly from each provider, so folks may reference respective definitions themselves.

This first chart is showing [RUM: ‘Page Load Time’] metric and [Synthetic: full ‘Webpage Response’] metric:


Should not be surprised to see the RUM Response Times are higher than Synthetic Response Times. Was curious, though, why the RUM times on occasion dipped below the Synthetic times. After looking around, found GeoDB to be the culprit.

This second chart is showing [RUM: ‘Server Response’] metric and [Synthetic: ‘Server Response’] metric:


Was a bit surprised the RUM times here were lower than the Synthetic times. After looking around, discovered the RUM ‘Server Response Time’ did not include redirect or connect times, where the Synthetic ‘Server Response’ did.

When looking at these charts, one could almost remove the Y axis values and look at the lines by themselves. Did the next value in the series increase, decrease or remain the same versus the previous value? If there was a change, was it sustained or was it transient?

Here’s where is considered the instrumentation of your Performance measurements, to figure what may cause the hills and valleys. Remember, “If you do not measure Performance, then Performance will not be measured”. May or may not always be able to tell why the Response Times change, but that’s part of the fun!

Document Complete / OnLoad:

_The following is optional reading material._

LinkedIn: http://www.linkedin.com/in/leovasiliou

Twitter: @LvasiLiou

#CatchpointUser #KeynoteUser #GomezUser #Webtortoise #Performance #WebPerformance #SiteSpeed

#RealUserMeasurements #RUM #SyntheticTests

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