Monday, December 27, 2004

The Philosophy of Profilers

When you are writing a profiler, you can choose from two ways of collecting data: probing and sampling.

A probe profiler collects data by inserting probes or hooks into the application so the profiler runtime is called whenever the program executes that hook. It has the following benefits:
  • The inserted probes will always be called when the application executes.
  • Having a complete picture of the run
  • Parent-child relationships between functions is guaranteed to be correct and the profiler can report perfect call trees necessary for you to easily find the call paths that took the longest time.

It has the following drawbacks:

  • The instrumentation scheme can be cumbersome to use
  • Since it's rewriting at the binary level, there's plenty of areas to introduce potential errors.
  • Probes also take up space, resulting in some code bloat and slower performance.
  • Slowdown makes almost impossible to run the instrumented binary on a production system

Sampling profilers take a snapshot of what's executing in the application at predefined intervals. VS Debugger is an example. It has the following benefits:

  • Having far less overhead than probe profilers.
  • Standing a much greater chance of using them on a production system without grinding the server to a halt.

It has the following drawbacks:

  • It's entirely possible that all the samples taken of your application could show no code at all.
  • Traditional sampling profilers that only grab the currently executing instruction for each thread make it much more difficult to determine the parent-child relationship between methods, so determining the worst performing code path is much more difficult.

Notes above are taken from John Robbins's article:

Make Your Apps Fly with the New Enterprise Performance Tool

5 Comments:

At 5:13 PM, Blogger ninest123 said...

louis vuitton outlet, ugg boots, ray ban sunglasses, oakley sunglasses, louis vuitton outlet, longchamp pas cher, prada outlet, polo ralph lauren outlet, nike outlet, chanel handbags, louboutin outlet, longchamp outlet, louis vuitton, nike air max, cheap oakley sunglasses, longchamp outlet, jordan shoes, louis vuitton, nike free, tiffany and co, tory burch outlet, prada handbags, replica watches, nike roshe run, longchamp, louboutin, air max, ralph lauren pas cher, christian louboutin outlet, replica watches, louis vuitton, nike air max, kate spade outlet, louboutin pas cher, nike free, oakley sunglasses, sac longchamp, oakley sunglasses, polo ralph lauren outlet, louboutin shoes, uggs on sale, ray ban sunglasses, ray ban sunglasses, burberry, gucci outlet, oakley sunglasses, tiffany jewelry, ugg boots, air jordan pas cher, michael kors

 
At 5:15 PM, Blogger ninest123 said...

coach outlet, ugg boots, vans pas cher, michael kors, hollister, coach purses, nike air max, ray ban uk, sac guess, ray ban pas cher, mulberry, true religion outlet, hermes, michael kors outlet, oakley pas cher, true religion jeans, lacoste pas cher, ugg boots, michael kors outlet, michael kors outlet, true religion jeans, nike free run uk, tn pas cher, michael kors, nike air max, burberry, vanessa bruno, lululemon, nike roshe, nike air max, ralph lauren uk, coach outlet, north face, replica handbags, nike blazer, converse pas cher, michael kors outlet, timberland, michael kors, abercrombie and fitch, hollister pas cher, true religion jeans, air force, burberry outlet online, michael kors, michael kors outlet, new balance pas cher, north face, kate spade handbags, hogan

 
At 5:19 PM, Blogger ninest123 said...

mont blanc, nike air max, babyliss, mcm handbags, louboutin, herve leger, ghd, hollister, celine handbags, lancel, new balance, nike trainers, valentino shoes, nfl jerseys, reebok shoes, soccer shoes, oakley, vans shoes, p90x workout, soccer jerseys, nike huarache, converse outlet, nike roshe, abercrombie and fitch, bottega veneta, north face outlet, beats by dre, birkin bag, instyler, gucci, mac cosmetics, chi flat iron, ferragamo shoes, insanity workout, ralph lauren, nike air max, jimmy choo shoes, longchamp, wedding dresses, asics running shoes, vans, hollister, timberland boots, iphone cases, baseball bats, hollister, giuseppe zanotti, north face outlet, ray ban, lululemon

 
At 5:24 PM, Blogger ninest123 said...

montre pas cher, moncler outlet, moncler, karen millen, moncler, supra shoes, ugg pas cher, wedding dresses, swarovski, moncler, sac louis vuitton pas cher, doudoune canada goose, moncler, louis vuitton, pandora charms, canada goose, ugg,uggs,uggs canada, swarovski crystal, marc jacobs, hollister, moncler, toms shoes, louis vuitton, ugg boots uk, louis vuitton, canada goose uk, coach outlet, louis vuitton, moncler, canada goose, pandora charms, links of london, moncler, canada goose, canada goose outlet, pandora jewelry, juicy couture outlet, canada goose, thomas sabo, juicy couture outlet, pandora jewelry, bottes ugg, canada goose outlet, ugg,ugg australia,ugg italia, replica watches

 
At 5:24 PM, Blogger ninest123 said...

montre pas cher, moncler outlet, moncler, karen millen, moncler, supra shoes, ugg pas cher, wedding dresses, swarovski, moncler, sac louis vuitton pas cher, doudoune canada goose, moncler, louis vuitton, pandora charms, canada goose, ugg,uggs,uggs canada, swarovski crystal, marc jacobs, hollister, moncler, toms shoes, louis vuitton, ugg boots uk, louis vuitton, canada goose uk, coach outlet, louis vuitton, moncler, canada goose, pandora charms, links of london, moncler, canada goose, canada goose outlet, pandora jewelry, juicy couture outlet, canada goose, thomas sabo, juicy couture outlet, pandora jewelry, bottes ugg, canada goose outlet, ugg,ugg australia,ugg italia, replica watches

 

Post a Comment

<< Home