If many queries come in too quickly, apache2 freezes.
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
apache2 (Ubuntu) |
Confirmed
|
Low
|
Unassigned |
Bug Description
I have set up a Xeon-based server with a number of Subversion repositories, served through libmod-dav_svn on apache2, and using OpenLDAP to provide directory and authentication services.
Now for simple queries, for instance from a Windows desktop using TortoiseSVN, there is no problem with this. In fact it works beautifully. However when doing a more complex query involving multiple rapid accesses it causes all the free apache threads to be consumed, which all appear to be stuck in a loop waiting for a response from slapd, which has already been given. The Subversive plugin for Eclipse seems to cause this nearly every time.
Here's the kicker: when I turned on logging in slapd using loglevel 256 (for example), the problem goes away. Could it be that the request for info is fired off, then slapd responds before mod-dav_svn is ready for the response, whereas if it is slowed down by logging, the Apache module is ready in time? I'd have expected some sort of pipeline in there, but who knows?
Here's slapd.conf:
# This is the main slapd configuration file. See slapd.conf(5) for more
# info on the configuration options.
#######
# Global Directives:
# Features to permit
#allow bind_v2
# Schema and objectClass definitions
include /etc/ldap/
include /etc/ldap/
include /etc/ldap/
include /etc/ldap/
include /etc/ldap/
TLSCACertificat
TLSCertificateFile /etc/ldap/
TLSCertificateK
pidfile /var/run/
argsfile /var/run/
loglevel 256
modulepath /usr/lib/ldap
moduleload back_hdb
tool-threads 1
sizelimit 500
backend hdb
database hdb
suffix "dc=netdb,
rootdn "cn=admin,
rootpw passwerd
directory "/var/lib/ldap"
dbconfig set_cachesize 0 2097152 0
dbconfig set_lk_max_objects 1500
dbconfig set_lk_max_locks 1500
dbconfig set_lk_max_lockers 1500
index cn,sn,uid pres,eq,sub
index objectClass eq
lastmod on
checkpoint 512 30
replogfile /var/lib/
access to attrs=userPassw
by dn="cn=
by anonymous auth
by self write
by * none
access to *
by dn="cn=
by * read
And here's the setup for the repos:
LDAPTrustedGlob
NameVirtualHost *:443
<VirtualHost *:443>
ServerAdmin <email address hidden>
ServerName netdb.cark.com
SSLEngine On
SSLCACertific
SSLCertificat
SSLCertificat
SSLProtocol all
SSLCipherSuite HIGH:MEDIUM
LDAPTrustedMode TLS
<Location /svn>
Order allow,deny
Allow from all
SSLRequireSSL
DAV svn
SVNParentPath /home/svn/
SVNListPare
AuthType Basic
AuthName "Subversion Repository"
AuthBasicPr
AuthzLDAPAu
AuthLDAPUrl ldap://
AuthLDAPGro
AuthLDAPGro
Require ldap-group cn=subversion,
# Other testing with files
# AuthUserFile /etc/apache2/
# AuthzSVNAccessFile /etc/apache2/
# Require valid-user
</Location>
ErrorLog /var/log/
# Possible values include: debug, info, notice, warn, error, crit, alert, emerg.
LogLevel warn
CustomLog /var/log/
</VirtualHost>
Changed in apache2 (Ubuntu): | |
importance: | Undecided → Low |
status: | Incomplete → Confirmed |
Which versions of apache and Ubuntu are you using?
Thanks
chuck