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Description of problem: An appache server with mod_python loaded cause memory leak when I do "service httpd reload". Version-Release number of selected component (if applicable): httpd-2.2.3-31.el5 python-2.4.3-27.el5 mod_python-3.2.8-3.1 How reproducible: Always Steps to Reproduce: 1. Install httpd, python and mod_python RPMs. 2. LoadModule python_module is enabled in /etc/httpd/conf.d/python.conf 3. Start httpd service. 4. top -bn1 |grep httpd 5. service httpd reload Continue step 4 and 5 many times. Actual results: top(1) shows Virt and Res size of the httpd processes are increasing. Just after started httpd. # top -bn1 |grep httpd 14847 root 18 0 17996 9368 3972 S 0.0 0.9 0:00.34 httpd 14923 apache 15 0 17996 6248 832 S 0.0 0.6 0:00.00 httpd 14924 apache 15 0 17996 6248 832 S 0.0 0.6 0:00.00 httpd 14925 apache 15 0 17996 6248 832 S 0.0 0.6 0:00.00 httpd 14926 apache 19 0 17996 6248 832 S 0.0 0.6 0:00.00 httpd 14927 apache 19 0 17996 6248 832 S 0.0 0.6 0:00.00 httpd 14928 apache 19 0 17996 6248 832 S 0.0 0.6 0:00.00 httpd 14929 apache 19 0 17996 6248 832 S 0.0 0.6 0:00.00 httpd 14930 apache 24 0 17996 6248 832 S 0.0 0.6 0:00.00 httpd After 50 times of httpd reload. # top -bn1 |grep httpd 14847 root 18 0 59124 39m 3980 S 0.0 4.0 0:08.25 httpd 15823 apache 17 0 59124 36m 832 S 0.0 3.7 0:00.00 httpd 15824 apache 17 0 59124 36m 832 S 0.0 3.7 0:00.00 httpd 15825 apache 17 0 59124 36m 832 S 0.0 3.7 0:00.00 httpd 15826 apache 19 0 59124 36m 832 S 0.0 3.7 0:00.00 httpd 15827 apache 19 0 59124 36m 832 S 0.0 3.7 0:00.00 httpd 15828 apache 21 0 59124 36m 832 S 0.0 3.7 0:00.00 httpd 15829 apache 21 0 59124 36m 832 S 0.0 3.7 0:00.00 httpd 15830 apache 23 0 59124 36m 832 S 0.0 3.7 0:00.00 httpd 15836 root 15 0 5476 1268 1032 S 0.0 0.1 0:00.00 httpd 15841 root 20 0 12380 3844 2584 R 0.0 0.4 0:00.00 httpd After 150 times of httpd reload. # top -bn1 |grep httpd 14847 root 18 0 142m 104m 3984 S 0.0 10.5 0:48.49 httpd 17722 apache 17 0 142m 101m 832 S 0.0 10.2 0:00.00 httpd 17723 apache 18 0 142m 101m 832 S 0.0 10.2 0:00.00 httpd 17724 apache 19 0 142m 101m 832 S 0.0 10.2 0:00.00 httpd 17725 apache 19 0 142m 101m 832 S 0.0 10.2 0:00.00 httpd 17726 apache 21 0 142m 101m 832 S 0.0 10.2 0:00.00 httpd 17727 apache 22 0 142m 101m 832 S 0.0 10.2 0:00.00 httpd 17728 apache 24 0 142m 101m 832 S 0.0 10.2 0:00.00 httpd 17729 apache 24 0 142m 101m 832 S 0.0 10.2 0:00.00 httpd Expected results: The Virt/Res size should be keep smaller size even after many httpd reload. Additional info: This system is NOT using mod_python, but mod_python and python were installed as a default. So mod_python was enabled without my attention. This symptom was found during "512 reload cause httpd + mod_perl to crash" reproduce test on RHEL5. The symptom I was testing was not happened on RHEL5, though I found the other one.
I'm sorry to say that there seems to be little we can do to fix this. The Python interpreter is designed with certain parts of process state which cannot be cleaned up, causing memory leaks over time if the server is frequently SIGHUPed (which in turn, causes the Python interpreter to be reloaded). I would recommend, in order of preference: 1) do not load mod_python in configurations in which it is not used. 2) occassionally perform a "service httpd restart" to completely stop and start the server. 3) execute python scripts via an out-of-process interpreter, e.g. via CGI. I hope these answers are of some use.