PDQ Online Workshop, May 17-21, 2021

PDQ (Pretty Damn Quick) is a free, open source, performance analyzer available from the Performance Dynamics web site.

All modern computer systems, no matter how complex, can be thought of as a directed graph of individual buffers that hold requests until to be serviced at a shared computational resource, e.g., a CPU or disk. Since a buffer is just a queue, any computer infrastructure, from your laptop up to Facebook.com, can be represented as a directed graph of queues.

The directed arcs or arrows in such a graph correspond to workflows between different queues. In the parlance of queueing theory, a directed graph of queues is called a queueing network model. PDQ is a tool for predicting performance metrics such as, waiting time, throughput, optimal user-load.

Two major benefits of using PDQ are:

1. confirmation that monitored performance metrics have their expected values
2. predict performance for circumstances that lie beyond current measurements

Find out more about the workshop and register today.

PDQ 7.0 is Not a Turkey

Giving Thanks for the release of PDQ 7.0, after a 5-year drought, and just in time for the PDQW workshop next week.

New Featues

1. The introduction of the STREAMING solution method for OPEN queueing networks. (cf. CANON, which can still be used).
2. The CreateMultiNode() function is now defined for CLOSED queueing networks and distinguished via the MSC device type (cf. MSO for OPEN networks).
3. The format of Report() has been modified to make the various types of queueing network parameters clearer.
4. See the R Help pages in RStudio for details.
5. Run the demo(package="pdq") command in the R console to review a variety of PDQ 7 models.

Maintenance Changes

The migration of Python from 2 to 3 has introduced maintenance complications for PDQ. Python 3 may eventually be accommodated in future PDQ releases. Perl maintenance has ended with PDQ release 6.2, which to remain compatible with the Perl::PDQ book (2011).

Guerrilla 2018 Classes Now Open

All Guerrilla training classes are now open for registration.

1. GCAP: Guerrilla Capacity and Performance — From Counters to Containers and Clouds
2. GDAT: Guerrilla Data Analytics — Everything from Linear Regression to Machine Learning
3. PDQW: Pretty Damn Quick Workshop — Personal tuition for performance and capacity mgmt

The following highlights indicate the kind of thing you'll learn. Most especially, how to make better use of all that monitoring and load-testing data you keep collecting.

• How to save millions of dollars with a one-line performance model (video)
• How to minimize chargeback after you lift and shift to the cloud (video)
• How to correctly emulate web traffic on a load-testing rig (PDF)

See what Guerrilla grads are saying about these classes. And how many instructors do you know that are available for you from 9am to 9pm (or later) each day of your class?

Who should attend?

• IT architects
• Application developers
• Performance engineers
• Sysadmins (Linux, Unix, Windows)
• System engineers
• Test engineers
• Mainframe sysops (IBM. Hitachi, Fujitsu, Unisys)
• Database admins
• Devops practitioners
• SRE engineers
• Anyone interested in getting beyond performance monitoring

As usual, Sheraton Four Points has bedrooms available at the Performance Dynamics discounted rate. The room-booking link is on the registration page.

Tell a colleague and see you in September!

CPU Idle Is Not Like White Space

This post seems like it ought to be too trite to write but, I see the following performance gotcha cropping up over and over again.

Under pressure to consolidate resources, usually driven by management and especially regarding processor capacity, there is often an urge to "use up" any idle processor cycles. Idle processor capacity tends to be viewed like it's whitespace on a written page—just begging to be filled up.

The logical equivalent of filling up the "whitespace" is absorbing idle processor capacity by migrating applications that are currently running on other servers and turning those excess servers off or using them for something else.

2016 Guerrilla Training Schedule 2016

After a six month hiatus working on a major consulting gig, Guerrilla training classes are back in business with the three classic courses: Guerrilla Bootcamp (GBOOT), Guerrilla Capacity Planning (GCAP) and Guerrilla Data Analysis Techniques (GDAT).

See what graduates are saying about these courses.

Some course highlights:

• There are only 3 performance metrics you need to know
• How to quantify scalability with the Universal Scalability Law
• Hadoop performance and capacity management
• Virtualization Spectrum from hyper-threads to cloud services
• How to detect bad data
• Statistical forecasting techniques
• Machine learning algorithms applied to performance data

Register online. Early-bird discounts run through the end of July.

As usual, Sheraton Four Points has bedrooms available at the Performance Dynamics discounted rate.

Tell a friend and see you in September!

Next GCaP Class: September 21, 2015

The next Guerrilla Capacity Planning class will be held during the week of September 21, 2015 at our new Sheraton Four Points location in Pleastaton, California. Early bird rate ends August 21st.

During the class, I will bust some entrenched CaP management myths (in no particular order):

• All performance measurements are wrong by definition.
• There is no response-time knee.
• Throughput is not the same as execution rate.
• Throughput and latency metrics are related — nonlinearly.
• There is no parallel computing.

No particular knowledge about capacity and performance management is assumed.

Attendees should bring their laptops as course materials are provided on CD or flash drive. The Sheraton provides free wi-fi to the internet.

We look forward to seeing you there!

Guerrilla Training: New Location

Finally! We have a new location for our Guerrilla training classes in Pleasanton, California: Sheraton Four Points.

We had some complaints last year about noise from the car parks of surrounding restaurants during the night at the previous location. Four Points is much more secluded. It also has its, own restaurant, which some of you will recognize if you've attended previous Guerrilla classes (more than likely, we did lunch and/or dinner there).

The current 2015 schedule and registration page is now posted. The classroom is intimate and only holds about 10-12 people, so book early, book often.

Guerrilla Data Analysis Class, May 19th

This is your fast track to enterprise performance and capacity management with an emphasis on applying R statistical tools to your performance data.

Discounts are available for 3 or more people from the same company. Enquire for details.

All classes are held at our lovely Larkspur Landing location in Pleasanton. Larkspur Landing also provides free Wi-Fi Internet access in their residence-style rooms, as well as our classroom.

Some of the topics covered will include:

• Introduction to using R
• How to Detect Bad Data
• Measurement Errors and Analysis
• Multivariate Linear and Nonlinear Regression
• Quantitative Scalability Analysis
• Statistical forecasting techniques for CaP
• Machine learning algorithms applied to CaP Data
• Wild Not Mild Data: SQL access, web traffic, data recovery
• Taming the Data Torrent with PCA and PerfViz techniques

Attendees should bring their laptops to the class as course materials are provided on a flash drive and calculational tools like OpenOffice, Excel and R will be useful.

Before registering online, take a look at what former students have said about their Guerrilla training experience.

Guerrilla Classes in March 2014

The upcoming GBoot and GCaP training classes are your fast track to enterprise performance and capacity management. You can now register entirely online using either your corporate or personal credit card.

New topics include:

• The effect of think-time settings in load tests
• Closed vs. open workloads in load testing

Classic topics include:

• There are only 3 performance metrics
• How performance metrics are related to each another
• How to quantify scalability with the Universal Scalability Law (USL)
• IT Infrastructure Library (ITIL) for Guerrillas
• The Virtualization Spectrum from hyperthreads to hyperservices

As usual, all classes are held at our lovely Larkspur Landing Pleasanton location in California. Attendees should bring their laptops to the class as course materials are provided on a flash drive. Larkspur Landing also provides free wi-fi Internet in their residence-style rooms as well as the training room.

Book Review: Botched Erlang B and C Functions

As a consequence of looking into a question on the GCaP google group about the telecom performance metric known as the busy hour, I came across this book.

A new copy comes with a $267.44 price tag!!! Here is my review; slightly enhanced from the version I wrote on Amazon.

Upcoming GDAT Class May 6-10, 2013

Enrollments are still open for the Level III Guerrilla Data Analysis Techniques class to be held during the week May 6—10. Early-bird discounts are still available. Enquire when you register.

As usual, all classes are held at our lovely Larkspur Landing location. Before registering online, take a look at what former students have said about the Guerrilla courses.

Attendees should bring their laptops, as course materials are provided on CD or flash drive. Larkspur Landing also provides free Internet wi-fi in all rooms.

Oracle Java 7 Security Vulnerability

National Cyber Awareness System

US-CERT Alert TA13-010A
Oracle Java 7 Security Manager Bypass Vulnerability

Original release date: January 10, 2013

Systems Affected

Any system using Oracle Java 7 (1.7, 1.7.0) including

• Java Platform Standard Edition 7 (Java SE 7)
• Java SE Development Kit (JDK 7)
• Java SE Runtime Environment (JRE 7)

All versions of Java 7 through update 10 are affected. Web browsers using the Java 7 plug-in are at high risk.

Guerrilla Stickers Stick It to the London Tube

It looks like the guerrilla subversive spirit of GCaP tactics has reached across The Pond to the London Underground in the form of patron-placed alternative signage.

The small irony here is that I refer to the London Tube map in my GCaP classes as a paradigm for performance models:

2.4 More Like The Map Than The Metro

When I was writing the GCaP book, I asked the London tube authority for permission to use their classically dense map. In incredible bout of British bureaucratic officiousness, they offered the tube map at £100 per impression—an offer my publisher was only too keen to refuse. Hence, the map you see on p. 9 of the GCaP book is that of BART, an authority who were pleased to see it further advertised by a taxpayer, as long as it was sourced—an offer my publisher was only too happy abide by.

Guerrilla Class of October 2012

This is what you missed last week: another fine Guerrilla al fresco lunch at the BlueAgave restaurant. Clearly, capacity planning is a tough business⎯when you do it right.

G'rillas at the grill: Joshua, NJG, Tim, Kevin, Tad, Manju

Here's some of what went down:

Plan for Capacity Planning Training in May

Bookings are open for both Guerrilla Boot Camp (GBoot) and Guerrilla Capacity Planning (GCaP) classes in May 2012 at the Early Bird rate.

As usual, classes will be held at our lovely Larkspur Landing location. Click on the image for booking information.

Before registering, take a look at some highlights students contributed from previous Guerrilla classes:

• May 2011
• August 2011

You too can be part of that educational experience.

Attendees should bring their laptops, as course materials are provided on CD or flash drive. The venue also offers free wi-fi to the internet.

Green Disk Sizing

I finally got around to completing item 5 on my 2011 list concerning electrical power consumed by a magnetic hard disk drive (HDD). The semi-empirical statement is:

Power ∝ N_platters × Ω^2.8 × D^4.6    . . .    (1)

where N_platters is the number of platters on the spindle, Ω is the rotational speed in revolutions per minute (RPM) and D the platter diameter in inches. The power consumed is then measured in Watts.

In principle, this makes (1) valuable for doing green HDD storage capacity planning. The bad news is, it is not in the form of an equation but a statement of proportionality, so it can't be used to calculate anything as it stands. More on that shortly. The good news is that all of the quantities in (1) can be read off from the data sheet of the respective disk vendor^†. Note that the disk capacity, e.g., GB (the usual capacity planning metric) does not appear in (1).

The outstanding question is: where do those funny non-integral exponents come from?

May 2011 Guerrilla Classes: Light Bulb Moments

It's impossible to know what will constitute a light bulb moment for someone else. In the recent Guerrilla classes (GBoot and GCaP), we seemed to be having many more than our usual quota of such moments. So much so, that I decided to keep a list.

CMG Atlanta: Southbound for the Deep South

I will be at the CMG Greater Atlanta Spring conference on April 27, 2011. I was asked to cover something for both veterans and newcomers to capacity planning—along the lines of my Guerrilla Boot Camp classes. So, here's what I came up with.

Guerrilla CaP for Noobs and Nerds
Whether you're a newbie (noob) or a veteran (nerd) when it comes to capacity planning (CaP) and performance analysis, it never hurts to revisit the fundamentals. However, some CaP concepts that are touted as fundamental are actually myths. Here are some myths I hear all too often.

What's NOT:

1. We don't need no stinkin' CaP, just more cheap servers.
2. CPU utilization should never exceed 70% busy.
3. A well-consolidated server should have no idle cycles.
4. Throughput and latency are independent metrics that must be measured separately.
5. Optimal response time is achieved at the knee of the curve.
6. If you can measure it, you can manage it.

During my twin session I will take these myths apart to expose the facts in terms of

What's HOT^†:

1. If the app is single-threaded, a boat-load of cheap servers from China won't help.
2. A 64-way server running 70% busy is 25% underutilized.
3. A consolidated server may need to be under 10% busy to meet app SLAs.
4. Throughput and latency are inversely related ... always!
5. Response time knees are an optical illusion.
6. All performance measurements are wrong by definition.

Along the way, I'll offer some Guerrilla mantras, as seen in my Guerrilla book and generated automatically on Twitter. You can use them as weapons of mass instruction to bust any other myths held by your colleagues and managers, whether you're a noob or nerd.

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† With apologies to Paris Hilton.

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Guerrilla Classes for 2011

The Guerrilla training schedule for 2011 has now been finalized.



Book early, book often!

Reporting Standard Errors for USL Coefficients

In a recent Guerrilla CaP Group discussion, Baron S. wrote:

....
BS> Using gnuplot against the dataset I gave, I get 
BS>    sigma   0.0207163 +/- 0.001323 (6.385%) 
BS>    kappa   0.000861226 +/- 5.414e-05 (6.287%) 

The Gnuplot output includes the errors for each of the universal scalability law (USL) coefficients. A question about the magnitude of these errors also arose in a recent talk I gave. Typically, this question doesn't come up because there's more focus on assessing the residual errors as a measure of fit for the USL against the data set. Also, statistical accuracy can be a bigger issue when there are only a small number of samples. Barron reported 32 data points, so that's not an problem in this case.