On September 12, 2011 8:06 , jana1972@xxxxxxxxxx wrote:
Ho can I solve this error( taken from the Apache2 log) *** glibc detected *** (wsgi:myweb: double free or corruption (!prev): 0x089e87c0 *** ======= Backtrace: ========= /lib/i686/cmov/libc.so.6[0xb7dba624] /lib/i686/cmov/libc.so.6(cfree+0x96)[0xb7dbc826] /usr/lib/libmysqlclient_r.so.15(my_no_flags_free+0x21)[0xb7a07e01] .... ... ... it continues further ... ..
The information you have provided shows that the problem is related to WSGI or the MySQL client library in some way. Neither one of these are a part of Apache HTTP Server, so the problem is not likely to be related to Apache. Instead, my guess is that the problem is related to whatever scripting language you are using via a third-party module to generate pages (Python, Ruby, PHP, or something else) and which in turn uses WSGI and MySQL.
Here is some generic advice for solving the problem:- See if you can get a complete backtrace. What you have posted omits a lot of information about where the problem occurred.
- See if you can get a backtrace that includes debugging symbol information. How to do this will depend on which operating system you are using; for example, if you are using Fedora like I am, see https://fedoraproject.org/wiki/StackTraces Additional debugging advice is available at https://httpd.apache.org/dev/debugging.html
- Check bug reports for the scripting language you are using to see if the problem you are encountering is a known issue and whether a fix or a workaround is available.
- Upgrade to the latest versions of your third-party software (scripting language, database client libraries, WSGI connector). This will make it easier to get support from the communities that support that software.
- Make sure that the versions of the software you are running are all compatible with one another. For example, if you are using Python and MySQL together, make sure that the version of MySQL you are using is supported by the version of Python you are using.
- Investigate the conditions under which the problem occurs. Try to narrow it down to specific scripts or operations, if possible.
- If you are not able to solve the problem, try isolating it. Sandbox the problematic scripts so that they run as child processes instead of running inside the web server itself; the scripts will still die, but their death will no longer directly affect the web server processes. A number of technologies are available for this, including CGI, FastCGI, and SGI. I see that you are using WSGI; if you have implemented this using mod_wsgi ( https://code.google.com/p/modwsgi/ ) then use mod_wsgi's 'daemon' mode to isolate the problematic script(s) from Apache.
Good luck. -- Mark Montague mark@xxxxxxxxxxx --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
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