1 What Guerrilla graduates are saying
- Wassim Dhib — LeadWire, France (2020):
I now apply the USL
(Universal Scalability Law)
whenever the opportunity arises.
It really changed my way of doing performance testing.
- Rob Franolic — DinerBytes, UK (2020):
Neil has a great deal of experience, and he offers unique perspectives
on performance and capacity planning. I attended his
PDQW workshop online
and gained a good understanding of queuing theory and how it applies to all
computing systems. Using his PDQ toolkit we learnt how to quickly get a
more fundamental understanding of the performance of any system.
- Annie F. — Intel, USA (2020):
Dr Gunther answered questions that had haunted me for years.
He enabled a visceral understanding of systems behavior with sufficient mathematics. Not too much, not too little.
I have been practicing systems performance analysis for 20 years, and the knowledge and understanding I gained from him is the booster fuel that takes me to a next level of the craft.
For those of you who love systems but are mathematically handicapped, take this class.
For those of you asking such deep questions as, "Why can most systems be modeled with a Poisson distribution?"
and, "What inner natural process makes them random?", take this class.
For those of you hitting a mid-career crisis on queuing theory
(but know enough to know that you don’t know enough), take this class.
I am thankful for the opportunity to learn from him.
I cannot wait to apply everything I have learnt.
- Rodrigo Nascimento — NetApp (2019):
Completed the Online
Guerrilla Capacity and Performance training
I’ve learned so much about
queueing theory and Little’s Law, and the
Universal Scalability Law
frameworks in past two weeks, it's totally changed the way I look at performance data.
- Ruslan Rusu — ClearMe.com (2019):
Blown away by
queueing theory and PDQ.
You get instant feedback for topology and optimization changes.
It will help you discard bad ideas before writing the code.
I even made "PDQtoGo"
to make it more accessible.
- Rudy Gevaert — Universiteit Gent, Belgium (2018):
Dr. Gunther has tons of experience and during his
he shares it freely. He takes you on a long journey, through woods
filled with queueing models, under bridges of concave USL graphs and up
mountains of exponential functions. Nonetheless, he never loses sight of applicability as the destination.
Dr. Gunther also takes the time to make sure you fully understand the
topics discussed. His storytelling is unique, which means you will learn much
more than what you signed up for. He makes sure he finds the right angle to get
the message across. The slides and accompanying books are excellent reference
works that should be on the shelf of any system administrator. As well as being
a formal teacher, Dr. Gunther is also a welcoming host who goes the
extra mile for his students.
- Mohit Chawla — Germany (2017):
It was gratifying to learn about the tools and techniques of data reduction and
visualisation for performance analysis in
more so when understood in
the context of the capacity planning concepts taught in
I also liked the way those two classes came together; especially the insight that although
real computer systems have correlations, those correlations are often weak and
therefore we can happily apply the exponential distribution as assumed in
Dr. Gunther also knows about the secret behind the success of
Edwin Hubble (more than a scatterplot)
(more than the 30,000 experiments),
which lies outside pure science. Find out more in the classes!
- Jeff Pickett — Covance (2016):
If you are involved with performance monitoring, analyzing performance, capacity
planning, and performance prediction, I highly recommend any of these courses.
If you are serious about performance and capacity management, then you will be
equipped with everything you need (and much more) to thrive in all things
performance and provide enterprise and business value.
- Joe Williams — GitHub (2015):
I really enjoyed participating in the
it was very helpful to get hands on with the techniques I had previously read about. While it took me a few
years to find an employer that would send me to the class it was well worth the
wait. Neil is a thoughtful instructor and I hope to take the
GDAT class at some
point. He also happens to pick great lunch spots during the week.
- Mimi Parsons — Expedia (2014):
Excellent training, well organized. Large amount of material was
presented in an understandable format. Dr Gunther found ways of explaining
abstract concepts in a simple way, providing best conceptual practices.
- Mike Brunt — CFWhisperer.com (2013):
After 15 years in server performance-tuning; I learned more in 5 days.
- Mark Cwetna — Schwab (2013):
It was a profound honor to attend your
Guerrilla Data Analysis Techniques
(GDAT) class this past week. I can't think of enough accolades to describe your
level of commitment to education, your in-depth knowledge of performance
technologies, analysis techniques and your infectious desire to instill quality
in every word/idea. In my lifetime you are one of the rarest breeds of
educators that I've ever had the good fortune to have experienced. I now have
the confidence, tools and educational prowess to go forth and spread the good
word. From the depths of my being I offer you my profound gratitude for sharing
your knowledge with me. I will do my best to honor you and the field of
capacity and performance to the best of my abilities.
- Maulan Byron — Comcast (2013):
The GCAP class
is frankly the best performance class I have attended. The
first 2 days alone were worth the price of admission. It was focussed and
detailed with very relevant examples. I'll be back for the
- Joshua Jin — Database Architect (2012):
The Guerrilla Capacity Planning
(GCAP) class is a fantastic class. Dr. Gunther has a
unique ability explaining the complex Queuing theory in such way that we all can
comprehend without much difficulties. He taught the class with passion. After
attending the training, I feel that his book contents are much easier to read.
To enhance the learning, Dr. Gunther demonstrated using Queuing Networks and
solving PDQ problems in R. For IT capacity professionals, this class prepares
you with knowledge, insight, and tools to be successful. It is highly
- Arun Kejariwal — Netflix (2012):
I enrolled to Neil's
Guerrilla Data Analysis
(GDAT) class based on the recommendation of my colleagues at work. The discussion about
and queuing models
apply to various scenarios was insightful. The discussion about Guftanson Trend and how it
compares to Amdahl's Law
was interesting. Last but not the least, I learned about new ways of
The fact that Neil shares his scripts is a big plus.
- Greg Rogers — Schwab (2011):
The fractal analysis of ORACLE query times in the
Guerrilla Data Analytics (GDAT) class
was awesome. It, along with Principal Components Analysis and Machine Learning, were worth the price of admission!
- Gary Little — NetApp (2011):
Putting together a trip report about recent
training. I'd forgotten how enjoyable it was.
[You're welcome. 1 —njg ]
- Asa Hendrick — SunTrust Bank (2011):
If your looking for training that will challenge your presumptions and help
you to think in new ways,
Guerrilla Capacity Planning
(GCAP) is an excellent choice.
In short, Dr. Gunther provided an excellent foundation and a new perspective
that will improve my effectiveness as a Capacity and Performance engineer.
- Thyya Ung — CoreLogic (2011):
It was an eye opening learning experience taking your class.
- Glenn Lockwood — U.S. Cellular (2010):
I especially enjoyed the first-hand war stories that make the
come alive. The progression of topics was brilliant. I found myself
pondering questions about digital filters and neural nets as analysis
tools only to find the topics covered subsequently. Even the coverage of
significant digits and rounding applies to current problems I am asked
to provide leadership and guidance on as a software engineer.
- Henry Colonna — Quest Diagnostics (2010):
Having taken your
Guerrilla Data Analysis Techniques
course I understand the beauty of mathematics and statistics in
resolving complex capacity and performance issues. Your course provides a
baseline in developing capacity reporting that is meanful to senior
management. Also, I have
R as a new tool in my arsenal to assist me.
- Ben Krein — AWeber.com (2010):
Recovering from a week at
Capacity Planning. Thanks again for the excellent and challenging class!
- Carl Davis — Oracle (2009):
The Guerrilla Capacity Planning class was by far the best technical class I have
been to. Dr Gunther made the class interesting by telling war stories from his many
years in the business and as a leader in the field of capacity planning. I would
strongly advise taking this class. There is no substitute for getting the knowledge
from the true expert in the field. I can't wait to put this knowledge to practice. I
look forward to take more classes from Dr Gunther.
- Joshua Barratt — Media Temple (2009):
Even though I have over 10 years of practical experience building and running
production systems, I left this class with a much deeper understanding of how,
fundamentally, to analyze questions of performance, scale, and capacity. I got some
practical skills that I was able to apply during the week of the class itself, as
well as a good introduction to a family of tools (like PDQ and R) that, while
they'll take some time to master, are already proving useful.
- Bryan Le — IBM (2009):
This course was outstanding. i really like the way he laid out the
concepts and gave examples of how to apply the concepts from his own
consultant experiences. I also like the model approach to performance
management and capacity planning.
- Greg Smyth — Facebook (2009):
Great course, I'll never look at
in the same way again!
- Mark Monaghan — Terraprova (2009):
When I am rummaging about in the bowels of systems, in a never ending
test/measure/tweak/tear at my few remaining hairs cycle in pursuit of
maximum performance, it is difficult to remember that a view from a bit
further back might be in order. The
GCaP class was refreshingly
practical and presented techniques and concepts that will be useful in
determining where to focus my efforts and provide clients and management
with information that can be readily grasped by all but the densest
nudniks. And let us not forget the
Universal Scalability Law.
This in itself is worth the price of admission. Throw in the never ending flow
of calories and the very relevant anecdotes and what you have is an
informative and enjoyable week that far surpasses any other industry
class I have attended.
- Joe Lenart — AETNA (2009):
I thought your Guerrilla
Capacity Planning class was highly insightful and full of great
techniques that I can apply immediately within my occupation as a Capacity
Planner. Your real-life examples and anecdotes have not only awakened my mind to
what to look for in situations that may be crucial in quickly identifying
capacity-related problems, but they were entertaining enough that I expect
the benefit of your experience will stick with me for a long time to come.
Your simplified, yet mathematically accurate equations (as you proved to us
in class) were much easier to understand and apply to real workplace
situations than much of the Ph.D thesis-level examples in other books. As a
result they are tools that will help me improve my understanding of complex
architectures and to better support them in short order.
I have already talked to my management about coming back for your follow-up
course, and have also spoken to the manager of our Performance Lab, as I
believe the techniques that you outline will be useful in helping my team
to work with them to design better application performance tests.
Thanks for your time and insights. I look forward to attending Guerilla
Capacity Planning—The Sequel.
- Stefan Parvu — Sun Microsystems/Nokia, Finland (2008):
The GCAP class
is highly recommended to any System Administrator or
System Service management personnel. Finally there is a class not about a software
product in particular but about concepts and methodologies of what is
Performance Analysis and Capacity Planning. Simple applied to our todays
economy the GCaP is a must for anyone involved in Capacity Planning and
Performance Analysis. GCaP served me as an example in building System Data Recorder,
a proof of concept around GCaP, which helps you look to your data center: analyzing
certain workloads, consolidate where is the case, ultimate saving energy.
- Vladimir Begun — Oracle (2008):
"We are the champions, ...." [quoting the Queen song in the context of Go forth and Kong-ka!].
(Guerrilla Boot Camp)
was great! I really like how you approach the issues; simplicity but not
over-simplification. The examples from your own experience are real gems in
the "crown" of the class. You know one cannot learn how to manage people
from a person who never managed a company and achieved something.
That's why I picked your class. When one wants to
learn something he should go not just for the information but from the right
person as well. Very good atmosphere, a clear and horizon-expanding presentation of
actual experiences in the capacity planning. About right for a jump-start!
Eager to attend the Level II class.
- Tim McCluskey — Independent (2008):
This (Guerrilla Boot Camp)
course was excellent! A very practical approach to performance
analysis, with real-world examples. Neil does an outstanding job
getting the material across with the utmost of simplicity. I recommend
this class to anyone who wants to gain the basics skills necessary for
capacity and performance management. I look forward to attending his
- Scott Roberts — UPS (2008):
Your work hits a fundamental truth; you're absolutely right in that
most capacity planning systems cost far too much and are too complex for
current development and implementation cycles. Using your methods I've
developed a new capacity planning workflow using Excel and Perl::PDQ which
saves a few months of work each year.
- Scott Christensen — MBA, PMP (2007):
Thank you for providing such a great class on Capacity Planning. I am
still thinking how great of a class it was. The class is by far the best
class that I have had, including previous capacity planning courses.
Having previously studied physical science, the connection of modeled data
to physical models proves to be very useful. Your choice of accommodations
and geographic proximity is excellent.
- Paul Puglia — Merrill Lynch (2006):
Guerilla Capacity Planning
(GCAP) is one of the best courses I've taken.
- Moses Chu — Kaiser Permanente (2006):
After I come back (from the class), I have attended a 12 hours
long Data Center project through the past weekend. After the work, I
thought about the theory and practice you have shared from your past
years experience. I would call this class a total value for Capacity
planners. The experience that you shared is particular worthwhile and
eye opening. I want to thank you for hosting such a event.
- Paul Cao — Hewlett-Packard (2006):
It's one of the best training classes I ever had (it's number one on my list).
- Henry Colonna — Quest Diagnostics (2006):
In general, it was a great course that provided a lot of information I
needed to report response time numbers. Also, It provided a lot of
information too how the capacity tool that I use works internally. I am
looking forward to start to use PDQ to produce refined models and use it
with my present toolset. (ps, I went to the grocery store this week and
discovered that I will never look at a grocery line the same again!!) ...
- Allen Blackburn — IBM (2004):
I'd like to thank you again for the class. I really learned a lot! I
was so excited to get back and try out the MVRA ('noisy fingers') that I
immediately started working on a script to collect the 6 different types
- Stuart Plotkin — MetLife (2004):
Thanks a lot for the class, it was really great. I think it was
brilliant how your were able to zero in on key concepts and drill them
in to our heads.
- Greg Rogers — Compaq (2001):
I definitely learned performance and CP methods I'd not previously encountered, from the
Guerilla Capacity Planning
- Ken Ward — Sprint (2000):
I found your 'Guerilla Capacity Planning' course to be the most
in-depth and interesting of all similar courses I've attended over the
years and, I continue to be impressed with your follow-up emails and
- Jeff and Eric — NetGain (1998):
Thank you for the great instruction. We are already applying it. In
thanks, we thought you might enjoy this book (
The Goal via Amazon.com) ...
it's about bottleneck indentification and adaption in a
factory floor 2 and a bit of a love story.
- Irwin Kraus — Amdahl Corp. (1995):
Useful? Are you kidding? Your treatment is by far the clearest and most pragmatic I have ever seen.
2 Attribution lost to the mists of time
- "Probably the most mind-expanding presentation I've seen."
"You have a gift for visualization and presentation!"
"I like the idea that someone in this world works with math
like Dr. Gunther does."
"You seemed to stir up quite an interest in a topic which
most people would prefer to ignore on the grounds that it is 'too
"What is hard to come by, is a person with both specialist
knowledge and the ability to convey it to others. You've demonstrated
this uncommon combination of qualities."
"Thanks for one of the best classes that has been presented to our group."
"The simplified queueing theory in itself was worth the price of admission!"
1Gary might be waxing a little too modest here.
No doubt he enjoyed it, at least in part, because he
contributed a lot
to the class with some very interesting questions and observations. Some of which I've yet
to blog about.
2As much as I deeply appreciate receiving gifts from students,
I had trouble appreciating the merits of this book. I simply cannot understand how the author can
take 140 pages (out of 340) to begin explaining something as simple as the
It's the process (in manufacturing and computing) with the longest service demand. Sorry guys.
File translated from
On 9 Apr 2021, 10:09.