|
Gregory (Grisha) Trubetskoy
grisha at modpython.org
Tue Apr 13 09:52:08 EST 2004
Thanks for the detailed report, we'll check it out. Grisha On Tue, 13 Apr 2004 stietke at diw.de wrote: > Hi guys, > > thank you for this extremely cool piece of software. I am very > happy with it. However there is one little problem I encountered > while playing with it. On my computer, the apache process seems > to leak memory when used with mod_python in certain configurations. > > In particular, it seems to leak memory when I use PythonOption > directives in a <Directory>...</Directory> context. > > I tried to figure out where the memory disapears using valgrind, > but the hundreds of lines valgrind spit out left me rather clueless. > > Maybe somebody here has any idea what is going on. > > Thank you in advance + all the best, > Stefan > > > summary: > -------- > Some mod_python directives, including PythonOption and PythonInterpreter, > seem to cause apache or mod_python to lose a certain, constant amount > of memory for each request mod_python handles. The number of bytes > lost each request seems to scale with the number of directives used. > > The apache process seems to lose memory when the mod_python module > is loaded with a certain configuration, independently of the actual > request beeing handled by mod_python. (see results 6 for details) > > versions: > --------- > apache 2.0.49 > mod_python 3.1.3 > python 2.3.3 > linux kernel 2.4.19 > libc6 2.3.1 > debian woody with some updates > > apache, python and mod_python are compiled from source. > > apache is compiled with prefork mpm to make testing easier (no threads), > but tests with worker mpm showed similar results in earlier tests. > > httpd.config: > ------------- > $ diff conf/httpd.conf conf/httpd-std.conf > 119,122c119,122 > < StartServers 1 > < MinSpareServers 1 > < MaxSpareServers 1 > < MaxClients 1 > --- > > StartServers 5 > > MinSpareServers 5 > > MaxSpareServers 10 > > MaxClients 150 > 219c219 > < Listen 127.0.0.1:10080 > --- > > Listen 80 > 233d232 > < LoadModule python_module > /home/stefan/apache_test/apache_prefork/modules/mod_python.so > 362,372d360 > < # > < # mod_python > < # > < AddHandler mod_python .py > < PythonHandler testdummy > < #PythonInterpreter pylet_interp > < #PythonDebug On > < #PythonOption x a > < #PythonOption y b > < #PythonOption z c > < > 493c481 > < LogLevel debug > --- > > LogLevel warn > > mod_python handler: > ------------------- > $ cat testdummy.py > def handler(req): > return 0 > > testprocedure: > -------------- > 1) warm up: ../apache/bin/ab -n 50000 -k http://localhost:10080/test.py > > 2) test: cat /proc/2315/status > httpd_status.txt; > for x in 1 2 3 4 5; do > ../apache/bin/ab -n 100000 -k http://localhost:10080/test.py; > cat /proc/2315/status >> httpd_status.txt; > done > > 3) see if the worker process grows in size: grep VmSize: httpd_status.txt > > results: > -------- > 1) with the mod_python configuration from above, no growth. > 2) with the line "PythonOption x a" enabled: > VmSize: 8776 kB > VmSize: 10348 kB ---> +1572 > VmSize: 11916 kB ---> +1568 > VmSize: 13488 kB ---> +1572 > VmSize: 15056 kB ---> +1568 > VmSize: 16624 kB ---> +1568 > total: ((16624 - 8776) * 1024) / 500000 = 16.07270 bytes/request > 3) with the PythonOption replaced with "PythonOption > xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx > aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" > (that is 100*x and 100*a): > result: exactly the same as 2). > 4) with "PythonOption x a" and "PythonOption y b" enabled: > VmSize: 9956 kB ---> +3924 > VmSize: 13880 kB ---> +3924 > VmSize: 17804 kB ---> +3924 > VmSize: 21728 kB ---> +3932 > VmSize: 25660 kB ---> +3924 > VmSize: 29584 kB > total: ((29584 - 9956) * 1024) / 500000 = 40.19814 bytes/request > 5) with additionally "PythonOption z c" enabled: > VmSize: 11532 kB > VmSize: 18620 kB ---> +7088 > VmSize: 25708 kB ---> +7088 > VmSize: 32792 kB ---> +7084 > VmSize: 39880 kB ---> +7088 > VmSize: 46968 kB ---> +7088 > total: ((46968 - 11532) * 1024) / 500000 = 72.57292 bytes/request > 6) with all PythonOptions disabled, but with > "PythonInterpreter pylet_interp" enabled: > result: exactly the same as 2). > BUT: after this test, i ran > ../apache/bin/ab -n 300000 -k http://localhost:10080/index.html.en > without restarting apache, and the VmSize grew again to 21328 kB. > ((21328 - 16624) * 1024) / 300000 = 16.05632 > Apparently, apache loses memory already when the mod_python > module is loaded but does not handle the request at hand. > > > > _______________________________________________ > Mod_python mailing list > Mod_python at modpython.org > http://mailman.modpython.org/mailman/listinfo/mod_python >
|