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Created attachment 590152 [details]
httpd-2.2.15-ldapna.patch

Hi.

It happens that our LDAP server (Novell eDirectory) SOMEHOW gets unavailable and it causes 500 Internal Server Error on an authenticated page after filling in user credentials. After reloading page using <F5>, the LDAP-protected content finally appears.

The problem exists only a few seconds after httpd is idle for several minutes. Then it works continuously without any problem until next idle time of httpd.

The httpd debug message is:
auth_ldap authenticate: user  authentication failed; URI XXX [ldap_search_ext_s() for user failed][Server is unavailable]

The cause of this problem is given by this condition in util_ldap.h:
#if APR_HAS_MICROSOFT_LDAPSDK
#define AP_LDAP_IS_SERVER_DOWN(s)                ((s) == LDAP_SERVER_DOWN \
                ||(s) == LDAP_UNAVAILABLE)
#else
#define AP_LDAP_IS_SERVER_DOWN(s)                ((s) == LDAP_SERVER_DOWN)
#endif

I've simplified it:
#define AP_LDAP_IS_SERVER_DOWN(s)                ((s) == LDAP_SERVER_DOWN \
                ||(s) == LDAP_UNAVAILABLE)

I'm attaching a patch, so you can try it. I'm using siege for testing and after applying the patch, the error 500 disappeared.

Cheers.
Filip

Created attachment 590153 [details]
httpd.spec.diff

Thanks Filip.  I've pushed this fix upstream:

http://svn.apache.org/viewvc?view=revision&revision=1348036

I can confirm the patch resolves the issue.

This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.

This request was erroneously removed from consideration in Red Hat Enterprise Linux 6.4, which is currently under development.  This request will be evaluated for inclusion in Red Hat Enterprise Linux 6.4.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHSA-2013-0512.html