BDB Index corruption (ITS#2323)

[leifj@it.su.se]

Full_Name: Leif Johansson
Version: 2.1.12 (db 4.1.25)
OS: Linux
URL: ftp://ftp.su.se/pub/users/leifj/Leif-Johansson-031220.tgz
Submission from: (NULL) (130.237.152.7)


Commonly used indices in my BDB backend are currupted every 7-10 days under
normal load. The result is that the dit is traversed for every search. The
fix is do a dump/reload of the database. Looking at a trace of a search 
indicates that back-bdb is unable to open the uid-index. I have enclosed
a tarball of a trace together with my slapd.conf and the bad index file 
and the ldap server log from the time when the error occured. In this log
at about the time when the problem _may_ have first occured there is a
single line

Feb 20 04:02:01 av-out2 slapd[13274]: <= bdb_equality_candidates: index_param
failed (18)

which is the only log message from the backend until the server was rebuilt
later that morning.

In the trace.out note the line 219 where the index fetch candidates fails
with:

bdb_idl_fetch_key: [b49d1940]
<= bdb_index_read: failed (-30991)

The search performed was a one-level search of objectClass=posixGroup below
dc=su,dc=se.