[Modules] mod_gnutls making Apache use 100% CPU

[Simon Josefsson]

Sander Marechal <s.marechal at jejik.com> writes:

> Simon Josefsson wrote:
>> Next step would be to
>> run 'gdb /usr/sbin/apache2 PID' or similar and then run 'bt'.
>> Installing apache2-dbg may help, if you are on debian.
>
> I have a backtrace, see the attachment. The last bit is this:

Thanks.  Definitely looks like a dbm problem, it busy-loops in libdb:

> #0  0x00007f50f6eb7bc9 in __memp_fget () from /usr/lib/libdb-4.6.so
> #1  0x00007f50f6e86827 in __db_doff () from /usr/lib/libdb-4.6.so
> #2  0x00007f50f6e12dbc in __ham_del_pair () from /usr/lib/libdb-4.6.so
> #3  0x00007f50f6e09f02 in __ham_quick_delete () from /usr/lib/libdb-4.6.so
> #4  0x00007f50f6e6da3c in __db_del () from /usr/lib/libdb-4.6.so
> #5  0x00007f50f6e7fbfc in __db_del_pp () from /usr/lib/libdb-4.6.so
> #6  0x00007f50f7d0e377 in ?? () from /usr/lib/libaprutil-1.so.0
> #7  0x00007f50f046368e in ?? () from /usr/lib/apache2/modules/mod_gnutls.so
> #8  0x00007f50f046398e in ?? () from /usr/lib/apache2/modules/mod_gnutls.so
> #9  0x00007f50f53f484d in _gnutls_store_session () from
> /usr/lib/libgnutls.so.26

Maybe libdb people are interested in your cache file, to debug this,
although it does contain sensitive information so be careful about
sending it.

You could install memcached and modify
/etc/apache2/mods-available/gnutls.conf to use it instead of a dbm file.

Btw, your MTA refuses direct e-mails:

We're sorry, but the user account you are trying to reach has exceeded its
size limit.  As a result, we were unable to deliver this message to the
intended recipient.  Please try sending this message again at a later time.

Reporting-MTA: DNS; mycingular.com
Received-From-MTA: DNS; [204.9.89.153]

Final-Recipient: RFC822; clague at mycingular.com
Action: failed
Status: 5.2.2
Remote-MTA: DNS; mycingular.com
Diagnostic-Code: 550 s...user over quota

/Simon