Corruption of Index files running readonly slapd (ITS#2582)

[ldap@uic.edu]

Full_Name: Andrew J. Herbert
Version: 2.1.21
OS: Linux 
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (128.248.172.135)


System master and slave pair running openldap v2.1.21 and Berkeley DB 4.1.25 on
Linux 2.4.18 systems (RH7.3 with updates) filesystems are ext3.

We have an issue using the PADL software pam_ldap module on a Solaris V880 with
approx 40,000 users against OpenLDAP. pam_ldap is not configured with the root
DN and the ACL are setup to allow no modification by anyone bar the root DN. As
such the LDAP database can be considered to be read-only.

After running for a few hours, the server starts taking an inordinately long (>1
min) to do a simple lookup. If we stop the server and compare the database files
with a 'known good' one, we find that the files have changed. Performing a
slapcat on the database takes in excess of 30 mins to run, but produces a
correct LDIF which can then be reloaded (around an hour for this) and the server
then continues to run normally for another few hours.

We can reproduce this, we have tried the following

Originally this system came online running 2.1.17 on a pair of IDE based
servers. We moved it to newer faster SCSI based servers (Sun LX50's) and still
had the same problems. We upgraded the system to 2.1.21 and the problem was
still present. If we leave the master and slave running long enough, eventually
they both enter this slow mode of operation.