Perrin Harkins wrote: > Josh Chamas wrote: > >> Set MaxRequestsPerChild to 100 for applications that seem to leak >> memory which include Embperl 2.0, HTML::Mason, and Template Toolkit. >> This is a more typical setting in a mod_perl type application that >> leaks memory, so should be fairly representative benchmark setting. > > > > Maybe I'm more careful about memory growth than some people, but 100 > sounds a bit on the low side to me. I use Apache::SizeLimit instead of
For the purposes of the benchmark, using Apache::SizeLimit won't do much the worst results are only showing 3M unshared per process & 8M total memory per process. The benchmarks run at 20 MaxClients. > MaxRequestsPerlChild, but I'm pretty sure every child serves more > requests than that. Did it seem to affect the performance numbers much? > For Embperl 2.x it made a world of difference on the memory side, with only a slight performance impact of 5-10%, but reduced memory usage from 60M to 25M for the test. Gerald & I have found real memory leaks in Embperl 2.x, where this kind of config is necessary. > Incidentally, I hate to call this stuff "memory leaks", since it's > usually just normal growth as memory gets used. Calling it "leaks" Right... I looked into HTML::Mason today, and agree with you and David that for HTML::Mason there is not a memory leak, it just uses more unshared memory than other environments at runtime, and the MaxRequestsPerChild did not seem to make a difference. This might also be true of Template Toolkit. I'll look into the latter more. I just assumed if the unshared memory footprint was as high as it was for these environments, that there must have been a leak like in Embperl 2.x. I also looked into AxKit which seems to use more memory, but it too does not seem to have a leak. > implies that memory is being wasted as a result of mistakes with > pointers or some such. When people hear "memory leaks" they go running > for stuff like Apache::Leak, thinking they can find some problem and fix > it, which is usually not the case. Right. What I go for in the benchmarks as far as a memory leak goes is do the environments seem to use the same amount of memory at 30 seconds as they do at 60 seconds. In the case of Embperl 2.x, this was very different, but in the case of HTML::Mason, it stays the same. Thanks as always for your feedback. --Josh
