Re: Log_file behavior in long running apps

# jon@php.net / 2003-07-04 13:50:55 -0400: > On Fri, Jul 04, 2003 at 12:02:01PM +0200, Roman Neuhauser wrote: > > > > > What effect will using Log::file in a long running application (non-web > > > > environment) have on memory usage given that it defers the writing till > > > > the end of the execution? > > > > > > I'm not sure. You'd have to run your own benchmarks. > > > > Well, I think we'll agree that it would cause evergrowing memory > > consupmtion. > > > > It also hampers functionality. Imagine any daemon like Apache only > > writing its logs on shutdown. You wouldn't be able to monitor its > > activity. > > Sure. I believe the current Log_file class was designed for > short-lived web scripts, where the total output would be reasonable > and caching it is a performance win. The current Log_file is Richard Heyes' work committed by you in 1.11 (AFAICT from cvs.php.net). Given that it used to actually call fwrite() in log() up untill 1.10, this is a regression (what you said still applies). Now, take this with a grain of salt as I'm your average PHP hacker, isn't this optimization a matter of (not) calling fsync(2)? I haven't read the source, and www.php.net/fflush doesn't mention fsync() at all, so I'm not sure. Ok, you got me to test it. log.1 is a bit slower than log.2, making the performance gain negative (I'm using 4.3.2-cli): // log.1 $msg = "World without heroes is like a world without sun, you can't look up to anyone without heroes."; $fd = fopen('/tmp/2.out', 'w'); $msgs = array(); for ($i = 0; $i < 10000; $i++) { array_push($msgs, $msg); } for ($i = 0; $i < 10000; $i++) { fwrite($fd, $msgs[$i]); } fclose($fd); // log.2 $msg = "World without heroes is like a world without sun, you can't look up to anyone without heroes."; $fd = fopen('/tmp/1.out', 'w'); for ($i = 0; $i < 10000; $i++) { fwrite($fd, $msg); } fclose($fd); It's not so strange when you think about all the stuff what PHP does to maintain that array. > > > When I find the time to rewrite the Log_file class, I'll make the > > > output buffering optional. > > > > What are the other changes you want to make? > > People have been asking for configurable timestamp and output formats. Add reverting to fwrite() right in log() to that list, please. :) -- If you cc me or remove the list(s) completely I'll most likely ignore your message. see http://www.eyrie.org./~eagle/faqs/questions.html