2 ms·

> "Optimize something" I may be the only one, but knowing what the 'something' was is incredibly valuable bc we all, as people, pick 'something' and not everyt

by TheBiv 13y ago

> "Optimize something" I may be the only one, but knowing what the 'something' was is incredibly valuable bc we all, as people, pick 'something' and not everything in any sort of bullet is created equal.

stephengillie 13y ago
Pick one of the "somethings" which is having the biggest impact to your product or service. Repeat.
dredmorbius 13y ago
In performance tuning, this is actually pretty straightforward: - Processes which run many times. - Processes which run long time (and block other processing). - If at all possible: both. The more subtle approach is to identify things you don't need to do (needless initializations, "settle" delays, doing (or allowing to be done) the _wrong_ thing requiring both unwinding that operation _and_ doing the right one, and anything you don't have to wait for (if it's an ancillary process, spin it off and handle it out-of-sequence). Redesigning a process to avoid sorting data. Eliminating global locks. Spinning off tasks to parallelized processing (especially if you have multiple cores/systems available. Pipelining data to avoid writing/reading from disk multiple times. Handling data in memory rather than on disk. Realizing you _can_ handle data in-memory, and that disk-seeks will kill you, so sorting or bucketing output. Swapping spinning rust for SSD. Specific tools such as COW, snapshots, or the like can be very useful in such cases. Algorithms (or methods invoking algorithms) can be another big win. I've seen processes fall in time requirements by 90% following such an optimization process.
stephencanon 13y ago
1. Use a sampling profiler on the important execution scenarios. 2. Identify the operation that is taking the most time. 3. Ensure it is using appropriate algorithms and data structures. 4. Profile again; if it is still taking the most time, hand-optimize it. 5. Goto 1

by TheBiv 13y ago

stephengillie 13y ago

Pick one of the "somethings" which is having the biggest impact to your product or service. Repeat.

dredmorbius 13y ago

In performance tuning, this is actually pretty straightforward: - Processes which run many times. - Processes which run long time (and block other processing). - If at all possible: both. The more subtle approach is to identify things you don't need to do (needless initializations, "settle" delays, doing (or allowing to be done) the _wrong_ thing requiring both unwinding that operation _and_ doing the right one, and anything you don't have to wait for (if it's an ancillary process, spin it off and handle it out-of-sequence). Redesigning a process to avoid sorting data. Eliminating global locks. Spinning off tasks to parallelized processing (especially if you have multiple cores/systems available. Pipelining data to avoid writing/reading from disk multiple times. Handling data in memory rather than on disk. Realizing you _can_ handle data in-memory, and that disk-seeks will kill you, so sorting or bucketing output. Swapping spinning rust for SSD. Specific tools such as COW, snapshots, or the like can be very useful in such cases. Algorithms (or methods invoking algorithms) can be another big win. I've seen processes fall in time requirements by 90% following such an optimization process.

stephencanon 13y ago

1. Use a sampling profiler on the important execution scenarios. 2. Identify the operation that is taking the most time. 3. Ensure it is using appropriate algorithms and data structures. 4. Profile again; if it is still taking the most time, hand-optimize it. 5. Goto 1