Database & Technology 1 _ Craig Shallahamer _ Unit of work time based performance analytics.pdf
- 1. Unit of Work Time Based Analysis Craig A. Shallahamer Founder - OraPub, Inc. craig@orapub.com SQL Elapsed Time Analysis
- 2. OraPub is about Oracle performance. • OraPub is all about Oracle performance Resources management; systematic and quantitative firefighting and predictive analysis. • Training • Web site started in 1995 and the company was founded in 1998 by Craig Shallahamer. • Unique Blog • OraPub has always been about disseminating • Free Tools Oracle database centric technical information. • Consulting, training, books, papers, and • Free Papers products are now being offered. • Books • We have been on-site in 24 countries and our resources have been received in probably • Products every country where there are DBAs. • Consul8ng SQL Elapsed Time Analysis
- 3. Short resume...kind of... • Studies economics, mathematics, and computer science at university in California, US. • Started working with Oracle technology in 1989 as a Forms 2.3 developer on Oracle version 5. • Soon after started performance firefighting...daily! • Co-found both Oracle’s Core Technology and System Performance Groups. • Left Oracle to start OraPub, Inc. in 1998. • Authored 24 technical papers and worked in 24 countries. • Authors and teaches his classes Oracle Performance Firefighting, Adv Oracle Performance Analysis, and Oracle Forecasting & Predictive Analysis. • Authored the books, Forecasting Oracle Performance and Oracle Performance Firefighting. • Oracle ACE Director. • Frequent blog contributor: A Wider View SQL Elapsed Time Analysis
- 4. My two books... OraPub discount code: IS11 SQL Elapsed Time Analysis
- 5. Performance analysis philosophies. • Ratio Analysis is the traditional method relying on simple calculations leading one to the problem area. “When the ratios are right, then so is performance.”...not always! • Wait Event Analysis (WEA) listens to where Oracle says it’s not consuming CPU resources. “When I bring down the top wait event, users are happier.” ...not always! • Time Based Analysis (TBA) is centred on interval time, elapsed time, and quantifying the users’ experience, at least in part. TBA is relative to ones perspective and should include CPU time. “When total time is decreases, performance increases.”...not always! • Unit of Work Time Based Analysis unites Oracle TBA with Operations Research by creatively using the time it takes to process a single unit of work. The benefits are a deep understanding of cause and effect, solution comparison and evaluation, anticipating performance, complete analysis quantification, and enhanced visuals. “When LIO RT decreases, LIO dependent elapsed times also decrease until the workload increases too much.” SQL Elapsed Time Analysis
- 6. Situation, over a time interval(s). Other Non-Idle Time related to all the Wait Time IO work occurred for a specific period of time. Srvr Prc CPU Time Perhaps 1.8M PIOs occurred BG Prc during this interval. Source: Confio Software’s Igniter product. SQL Elapsed Time Analysis
- 7. Representing time associated with a single unit of work. If 1.8M PIOs occurred during a one hour interval and there was 3500 seconds of associated CPU and non-‐idle wait Lme, then on average, each PIO took 1.94 ms to complete. SQL Elapsed Time Analysis
- 8. Contrasting RT based approaches Non-‐Idle Wait Time Total 1500s Response Time CPU 3500s Time 2000s Focus: Focus: “This is what occurred.” “This is what we can expect this “This is what we should soluLon to do.” do.” “This is the elapsed Lme change.” SQL Elapsed Time Analysis
- 9. Poor Performing System Classic Fully Key Parameter Performance QuanLfied DerivaLon MathemaLcs ORTA Proposed Performance SoluLons Model ObjecLve SoluLon Analysis SQL Elapsed Time Analysis
- 10. First, plot a performance situation. SQL Elapsed Time Analysis
- 11. Second combine respected disciplines. St Rt:cpu = ⎛ St λ ⎞ M 1− ⎜ ⎝ M⎟ ⎠ SQL Elapsed Time Analysis
- 12. Third, objectively evaluate. SQL Elapsed Time Analysis
- 13. Keep it as simple as possible. Detail how to move from red to blue… Provide just enough informaLon to get your point across and saLsfy your audience. SQL Elapsed Time Analysis
- 14. Situation, time per work unit. Time related to compleLng a single unit of work. Graph created using OraPub’s RT Graph Template. SQL Elapsed Time Analysis
- 15. Moving: interval time to RT analysis. • Notice the focus change: From total interval time, to time per unit of work. • Situation. Over a 30 minute interval, 5000 PIOs occurred, 250 seconds of CPU was consumed, and sessions waited for 2000 seconds. Key performance areas degraded as PIOs increased. • Unit of work. We must choose an appropriate unit of work. (e.g., physical IO read requests) • Service Time. How much CPU is consumed per unit of work. (e.g., 250 sec / 5000 pio = 0.050 sec/pio) • Queue Time. How much non-idle wait time per unit of work. (e.g., 2000 sec / 5000 pio = 0.400 sec/pio) • Arrival Rate. How much work arrives per unit of time. (e.g., 5000 pio / 1800 sec = 2.778 pio/sec) • Response Time. Simply, service time plus queue time. (e.g., 0.050 sec/pio + 0.40 sec/pio = 0.45 sec/pio) SQL Elapsed Time Analysis
- 16. Creating the RT graph using M-Solver. http://filezone.orapub.com/cgi-bin/msolve.cgi! SQL Elapsed Time Analysis
- 17. All the key parameters are now available to create a clean RT graph, plus the M-Solver details. SQL Elapsed Time Analysis
- 18. Got the graph ! SQL Elapsed Time Analysis
- 19. Reality Check: A clear RT curve. SQL Elapsed Time Analysis
- 20. Reality Check: A clear RT curve. SQL Elapsed Time Analysis
- 21. Reality Check: Production system. source: http://aberdave.blogspot.com/2011/03/response-time-analysis-based-on-awr.html! SQL Elapsed Time Analysis
- 22. Reality Check: Altering insert batch size work: insert! time: ms! Batch Batch size 2 size 1 28%! More? http://shallahamer-orapub.blogspot.com/2010/05/insert-batch-size-performance-effects.html! SQL Elapsed Time Analysis
- 23. In summary…step by step. • Perform an Oracle response time analysis (ORTA). • Pick a good workload metric. • Gather the total workload. • Calculate the key and classic performance parameters. • Plot single point. • Create response time curve by combining performance situation with classic performance mathematics. • Objectively and scientifically compare alternative solutions! SQL Elapsed Time Analysis
- 24. Let’s Do It! http://filebank.orapub.com/perf_stats/SP_PDXPROD.txt! SQL Elapsed Time Analysis
- 25. Want to dig deeper? • Craig’s Blog – A W i d e r V i e w • Paper: Evaluating Alternative Performance Solutions • Training from OraPub Melbourne – Oracle Performance Firefighting (I) & Perth in – Adv Oracle Performance Analysis (II) Q2 2012 • Books – Oracle Performance Firefighting (C. Shallahamer) • Chapter 9 is FREE to download SQL Elapsed Time Analysis
- 26. Thank You! SQL Elapsed Time Analysis