Mod_wsgi worker processes segmentation fault (11)

Question

I am having a problem with my django application, which is hosted with apache/mod_wsgi. I added some matplotlib code into the application, and apache worker processes now crashing.

I reduced this problem to the following:

Without any matplotlib imports application works ok
when "import matplotlib" is added anywhere in the application, worker processes die with segfault and users see no reply from server
"import matplotlib" works just fine in commandline python interpreter - segfault happens only in apache processes

Here is the log entry:

[Tue May 24 08:29:08 2011] [notice] child pid 17576 exit signal Segmentation fault (11)

I cannot reproduce problem on other computer. I tried to remove (rm site-packages/matplotli*) and install different versions of matplotlib (0.99.3, 1.0.0, 1.0.1) I tried to install all modules in virtualenv and point to virtualenv from my .wsgi script.

I tried this: Error: child pid 6695 exit signal Segmentation fault (11) I read http://code.google.com/p/modwsgi/wiki/ as well.

Any pointers on how to debug/workaround this issue will be much appreciated.

(I am even ready to move to any other server (paste/cherrypy + apache mod_proxy, etc.) to eliminate the problem.)

Here are my apache settings:

/usr/sbin/httpd -V

Server version: Apache/2.2.15 (Unix)
Server built:   Apr 10 2010 11:21:07
Server's Module Magic Number: 20051115:24
Server loaded:  APR 1.3.9, APR-Util 1.3.10
Compiled using: APR 1.3.9, APR-Util 1.3.9
Architecture:   32-bit
Server MPM:     Prefork
  threaded:     no
    forked:     yes (variable process count)
Server compiled with....
 -D APACHE_MPM_DIR="server/mpm/prefork"
 -D APR_HAS_SENDFILE
 -D APR_HAS_MMAP
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D APR_USE_SYSVSEM_SERIALIZE
 -D APR_USE_PTHREAD_SERIALIZE
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
 -D APR_HAS_OTHER_CHILD
 -D AP_HAVE_RELIABLE_PIPED_LOGS
 -D DYNAMIC_MODULE_LIMIT=128
 -D HTTPD_ROOT="/etc/httpd"
 -D SUEXEC_BIN="/usr/sbin/suexec"
 -D DEFAULT_PIDLOG="logs/httpd.pid"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_LOCKFILE="logs/accept.lock"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="conf/mime.types"
 -D SERVER_CONFIG_FILE="conf/httpd.conf"

/usr/sbin/httpd -l

Compiled in modules:
  core.c
  prefork.c
  http_core.c
  mod_so.c

/usr/sbin/httpd -M

Loaded Modules:
 core_module (static)
 mpm_prefork_module (static)
 http_module (static)
 so_module (static)
 auth_basic_module (shared)
 auth_digest_module (shared)
 authn_file_module (shared)
 authn_alias_module (shared)
 authn_anon_module (shared)
 authn_dbm_module (shared)
 authn_default_module (shared)
 authz_host_module (shared)
 authz_user_module (shared)
 authz_owner_module (shared)
 authz_groupfile_module (shared)
 authz_dbm_module (shared)
 authz_default_module (shared)
 ldap_module (shared)
 authnz_ldap_module (shared)
 include_module (shared)
 log_config_module (shared)
 logio_module (shared)
 env_module (shared)
 ext_filter_module (shared)
 mime_magic_module (shared)
 expires_module (shared)
 deflate_module (shared)
 headers_module (shared)
 usertrack_module (shared)
 setenvif_module (shared)
 mime_module (shared)
 dav_module (shared)
 status_module (shared)
 autoindex_module (shared)
 info_module (shared)
 dav_fs_module (shared)
 vhost_alias_module (shared)
 negotiation_module (shared)
 dir_module (shared)
 actions_module (shared)
 speling_module (shared)
 userdir_module (shared)
 alias_module (shared)
 rewrite_module (shared)
 wsgi_module (shared)
 ssl_module (shared)
Syntax OK

Apache config



    ServerName              somesite.com
    DocumentRoot            "/somedir"

    WSGIApplicationGroup %{GLOBAL}
    WSGIScriptAlias / /somedir/production.wsgi

    <..>

Mod_wsgi worker processes segmentation fault (11)

Answers (1)

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