システムパフォーマンスの文脈で多変量解析に言及している本を探していて見つけた。
"When not maximizing efficiency, Craig is fly fishing, praying, backpacking, playing guitar, or just relaxing around a fire."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Abouttheauthor.html
このAbout the Authorの書き方憧れる。
"My goal is to teach you about real-world Oracle performance forecasting—period. There is no hidden agenda."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Introduction.html
なんかかなり熱い方だな。好印象。
"Within 60 minutes, you will be able to forecast performance and identify risk on you production Oracle database server. I kid you not. "
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Introduction.html
I kid you not. は「嘘じゃないよ」。
"Help manage service levels from a business value perspective.
Identify the risk of overutilized resources.
Predict which component of the architecture is at risk.
Predict when the system will be at risk.
Develop multiple risk mitigation strategies to ensure service levels are maintained."via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Introduction.html
これができたら最強だよな。単に勉強不足かもだが、あまり見ない観点の気がするのだが。
"But if you want to truly add value to your company and enhance your career, this chapter will be invaluable."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Introduction.html
なんというか、この著者はコンピテンシーが高い気がする。
"This chapter is important because, many times, a low-precision forecast will not meet your requirements. I'll present ways to increase forecast precision by selecting the appropriate forecast model, choosing the right workload activity, and calculating the deceptively simple term average. Along the way, you'll learn some additional technical tidbits."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Introduction.html
Chapter 3がまさに知りたいところだが、我慢して前から読んで見る。
"Ratio modeling is absolutely brilliant for architectural discussions, vendor recommendation sanity checks, and sizing of packaged applications. For the laboratory scientist, ratio modeling can be uncomfortable, but for the hands-on Oracle forecasting practitioner, it's beautiful."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Introduction.html
こういう実用的な態度が非常に好印象。
"if you are benchmark-focused, in addition to the foundational chapters, the chapter about workload characterization (Chapter 7) will be valuable."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Introduction.html
Benchmarkingとの関係は理解したい。
"The processes of SLM can be grouped into four management areas:"
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter01.html
- Capacity management
- Continuity management
- Availability management
- IT financial management
"You and I might not like what all this may imply, but the reality is that companies employ us because they must provide their customers with certain specific values and their hope is we can help in this process. In exchange for our services, they compensate us in a variety of ways that we must deem acceptable."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter01.html
徹底して面白い方だな。こんな技術書はあまり読んだことがない気がする。
"The world is much too complex for us to understand. To compensate, we create models to simplify the world around us, turning it into something we can comprehend. Models help us understand our world. When focused on a specific area in which the scope is very limited, a model can teach, expose, describe, reveal, and draw out the understanding we may desperately need. Modeling is all about making the complex simple."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter01.html
Modelingについていい説明を探していたが、これは非常に良い。
"For example, consider a paper airplane. Although it's extremely simple to construct and examine, it can help teach us about basic aerodynamics. But like all models, it has a very focused and limited use. That same paper airplane will not teach us about landing gear or traveling at supersonic speeds. To learn about these things, a different model is required."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter01.html
紙飛行機は航空力学は教えてくれるが、それ以外については教えてくれない。
"So please, remember that models are not reality. They are not perfect, cannot be expected to be perfect, and are not designed to be perfect. It would be foolish to think what a model says will absolutely 100% occur. Even proprietary forecast models are not perfect—close, but not perfect."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter01.html
モデルは現実ではない。モデルが示すことが100%起きるということはない。
"The perfect model is one that allows you to understand something you need to understand with minimal cost and effort."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter01.html
完璧なモデルは、あなたが最小限のコストと労力で理解する必要があるものを理解することを可能にするものです。
"There are three fundamental model types; mathematical, benchmark, and simulation. For sure, there are other forecasting models available. But these broad model categories will cover our work nicely, not leave gaping holes, and prepare us to assimilate other models when necessary."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter01.html
- Mathematical
- Benchmark
- Simulation
"A benchmark is a model because it simplifies something complex, highlighting areas we want to study. As explained in the "Differences Between Benchmarks and Simulations" section, a benchmark is not a true simulation because it runs the system it is studying."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter01.html
Benchmark/Model/Simulationの関係。
"A simulation program does not run on what is being studied. For example, during a nuclear physics simulation, actual atoms are not split. Traffic simulations are not run on the highway, but rather inside a computer. This is in stark contrast to a benchmark, where the benchmark is actually running Oracle, the software application, and the operating system on particular hardware."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter01.html
この定義は12. Benchmarking - Systems Performance: Enterprise and the Cloud [Book]とは違うな。著者も過去に使っていたと言っているように、Load generatorをSimulationと呼ぶ場合もあるだろうが、この本では明確に区別するという立場。私も今後はこのような定義を使おうかと。
"Sure, equations help us forecast, but equations can never fully capture the com plexities of a computing system, just as equations can never fully capture the complexities of a living system. But we can abstract and model these complexities."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter02.html
たぶん本書では一貫しているスタンス。
"So when thinking, working with, and forecasting Oracle performance, remember that computing systems are very dynamic, always shifting and changing, like you and I."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter02.html
ここらへんの動的を強調するのはOptimizing Java [Book]と共通するスタンス。
"Response time is service time plus queue time:
Rt = St + Qt"
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter02.html
この定義は使いたい。
共通認識にしたい。
"Notice that when the arrival rate is small, the response time is equal to the service time; that is, there is no queuing. But as more transactions enter the system per unit of time (that is, the arrival rate increases), queuing will eventually occur. Notice that just a little queuing occurs at the beginning. But as the arrival rate continues to increase, at some point (after 75% utilization), the queue time will skyrocket. When this occurs, the response time also skyrockets, performance slows, and users get extremely upset."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter02.html
Known unknown. 知っているようで体得できていない。
"The method I have used for years works exceptionally well with real-life Oracle systems (production or planned). This method involves six steps:"
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter02.html
- Step 1: Determine the study question.
- Step 2: Gather workload data.
- Step 3: Characterize the workload data.
- Step 4: Develop and use the appropriate model.
- Step 5: Validate the forecast.
- Step 6: Forecast.
"The process of transforming the raw data is known as workload characterization. I've devoted an entire chapter to workload characterization (Chapter 7) to handle the harsh realities of an Oracle environment."
via Check out this quote from Forecasting Oracle Performance - https://learning.oreilly.com/library/view/forecasting-oracle-performance/9781590598023/Chapter02.html
生データを加工することをworkload characterizationという。
