Dr. Neil Gunther
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drqz.bsky.social
Dr. Neil Gunther
@drqz.bsky.social
54 followers 26 following 110 posts
Performance analyst, 'rocket scientist' & Xerox PARC alum 🇦🇺🇺🇸 Consultant, author, teacher, physics, math, stats, chem and some 🎸 performance too.
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Dr. Neil Gunther @drqz.bsky.social · Nov 15
Performance issues are always lurking. Better to prepare for them and otherwise prevent them in the future.
Guerrilla Capacity & Performance online classes offer some of the most powerful techniques applied across all platforms. perfdynamics.com/Classes/sche...
drqz.bsky.social
Ordinary AI output requires extraordinary human verification. (Apologies to C. Sagan)
October 23, 2025 at 11:01 PM
drqz.bsky.social
October 22, 2025 at 4:49 PM
drqz.bsky.social
DR still in progress for AMZN.com itself ... 🧐
October 20, 2025 at 5:51 PM
drqz.bsky.social
Productivity: If you want to be more productive, go to sleep.
www.perfdynamics.com/Manifesto/gc...
October 13, 2025 at 6:32 AM
drqz.bsky.social
Some performance consequences often overlooked in redundancy plans
perfdynamics.blogspot.com/2014/03/perf...
Performance of N+1 Redundancy
How can you determine the performance impact on SLAs after an N+1 redundant hosting configuration fails over ? This question came up in the...
perfdynamics.blogspot.com
October 5, 2025 at 4:03 PM
drqz.bsky.social
Out of The Queue Comes ... Amdahl’s Law!
www.perfdynamics.com/Papers/amdsy...
September 18, 2025 at 5:10 PM
drqz.bsky.social
RIP James Lovell, commander of Apollo 13 (played by Tom Hanks in the movie of the same name), has died at age 97.
August 8, 2025 at 8:57 PM
drqz.bsky.social
A. Displaying metrics, errors, etc., is not the same thing as displaying metric errors.
1. How it is (old school top)
CPU usage: 5.79 %usr, 4.51 %sys, 89.68 %idl
2. How it could be (nay, SHOULD be)
CPU usage: 5.79 ± 0.29 %usr, 4.51 ± 0.23 %sys, 89.68 ± 4.48 %idl
August 7, 2025 at 5:43 PM
drqz.bsky.social
Online classroom buzz www.perfdynamics.com/Classes/comm...
What Guerrilla Grads are saying about why you should become an alumnus.
Enroll here www.perfdynamics.com/Classes/sche... 🎓

#performance #engineering #capacity #management #marketplace #trends #GCAP #GDAT #PDQW
August 6, 2025 at 1:07 PM
drqz.bsky.social
PSA: New open access Journal of Systems Scalability launching.
Editor-in-Chief: Carlos Juiz
www.icck.org/jss
#systems #architecture #performance #scalability
August 5, 2025 at 2:25 PM
drqz.bsky.social
GCAP Day 10. What you missed:
❥ Avalanche vs. Paxos coordination scalability
❥ Memcache scalability analysis with USL
❥ Queueing models of Kubernetes control and data planes
❥ Class dismissed 📚 🎓🍻
August 1, 2025 at 10:43 PM
drqz.bsky.social
Never let reality get in the way of a good performance model.
July 31, 2025 at 11:35 PM
drqz.bsky.social
GCAP Day 9. What you missed:
❥ Rate limiting services via Guerrilla queueing models
❥ Performance visualization tools
❥ Zookeeper scalability analysis with the USL
www.perfdynamics.com/Manifesto/US...
July 31, 2025 at 8:21 PM
drqz.bsky.social
GCAP Day 8. What you missed:
❥ Linear vs Dynamic programming
❥ Benchmarking/load testing prats and pitfalls
❥ Prelim discussion about Kefka, Kubernetes
❥ What kind of scheduler is in the K8s control plane?
July 30, 2025 at 10:17 PM
drqz.bsky.social
GCAP Day 7. What you missed:
❥ Python least_squares() seems to be a bloated implementation of codes in the "Numerical Recipes" book.
❥ To apply the USL, use curve_fit() instead.
❥ Multivariate regression: How to reattach (noisy) fingers to amputated daily "numero uno" data
July 29, 2025 at 8:25 PM
drqz.bsky.social
GCAP Day 6. What you missed:
❥ USL scalability analysis
lnkd.in/gxaaAiww
❥ Student gets PDQ 7.0 running on Python 3.12 👏🎉
lnkd.in/gPzzHiez
❥ Homework Q-5 solved (a) analytically (b) cf. with corresponding PyDQ model
- Discussed why analytic calculation was wrong
July 28, 2025 at 10:31 PM
drqz.bsky.social
Ditto for the performance analysis & capacity planning of computer systems in general:
- Assume failure
- Plan for resilience
- Monitor everything
- Analyze and predict performance and capacity
- Have an exceptional performance team of skilled experts

lnkd.in/g8eGRnYq
July 27, 2025 at 4:41 PM
drqz.bsky.social
RIP Chuck Mangione
www.youtube.com/watch?v=c4el...
Chuck Mangione - Feels So Good (The Old Grey Whistle Test, January 16th, 1979)
YouTube video by Chuck Mangione
www.youtube.com
July 25, 2025 at 5:30 AM
Reposted by Dr. Neil Gunther
drqz.bsky.social
Guerrilla Capacity Planning (GCAP) Online
— EU Edition — registration is now OPEN
Dates: July 21 through August 1, 2025
Times: 1500 - 1900 CET
www.perfdynamics.com/Classes/sche...

Click on the DETAILS box (at the RHS) to register
www.eventbrite.com/e/guerrilla-...
June 24, 2025 at 4:22 PM
drqz.bsky.social
#TIL Product Solutions Physicist 😳
July 3, 2025 at 2:51 AM
drqz.bsky.social
I recently discovered the original 1992 paper where I first introduced the concept of barycentric coordinates for visualizing multiprocessor/multicore performance. www.perfdynamics.com/papers.pdf

More modern renditions (animations) can be viewed here www.perfdynamics.com/Tools/tools....
July 1, 2025 at 6:03 PM
drqz.bsky.social
Yep.
July 1, 2025 at 6:04 AM
drqz.bsky.social
Guerrilla training classes (GCAP) online are brutal.
Despite the rumors, there are no long lunches.
Only performance zealots should apply.
Next class starts July 21, 2025.

www.perfdynamics.com/Classes/sche...

#Performance #Training
June 27, 2025 at 2:05 PM
drqz.bsky.social
Guerrilla Capacity Planning (GCAP) Online
— EU Edition — registration is now OPEN
Dates: July 21 through August 1, 2025
Times: 1500 - 1900 CET
www.perfdynamics.com/Classes/sche...

Click on the DETAILS box (at the RHS) to register
www.eventbrite.com/e/guerrilla-...
June 24, 2025 at 4:22 PM
drqz.bsky.social
TIL: Many happy returns of the day &
The spirit of @Lyft lifts your spirits.

1. My only phone slid out of my pants' pocket during a Lyft ride this morning. Fortunately, Lyft has a "Help/Lost my phone" web page that I could access from my laptop.
June 20, 2025 at 8:51 PM