(ITS#6599) slapd not responding

[binoy@cordys.com]

Full_Name: Binoy Joseph
Version: 2.4.21
OS: Linux
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (210.210.79.19)


I run OpenLDAP 2.4.21 configured to bdb on Windows and Linux. We run some
applications on top of our application framework which in turn is connected to
OpenLDAP via JLDAP. We list children of 'cn=soap nodes' (search LDAP) very often
as shown in the DIT below. I wrote a test case to create soapnode, soapproc,
connectionpoint and then delete them one after the other, ie I create set1,
delete set1, create set2, delete set2... Note that list children of 'cn=soap
nodes' happen in parallel as mentioned above.

Randomly but very consistently, suddenly we face an LDAP not responding issue.
When I connect via an LDAP Explorer, I am able to see and expand most of the
LDAP entries, except the 'cn=soap nodes' as shown in the DIT below, which says
LDAP query did not return indefinitely. CPU: slapd shoots to 50% in Windows and
100% in Linux. Then I have to kill slapd and start again.

This does not happen in OpenLDAP 2.4.16. After upgrading to 2.4.21 this started
happening. When I switched to hdb, this does not occur in Linux, but continues
to happen in Windows.
This also looks very similar to
http://www.openldap.org/its/index.cgi?findid=6322, Subject: slapd suddenly stops
working, and starts using 100% CPU.

o=org1
|
+-cn=soap nodes
   |
   +-cn=soapnode1
   |  |
   |  +cn=soapproc1
   |    |
   |    +cn=connectionpoint1
   |
   +-cn=soapnode2
   .
   .

Thanks and regards,
Binoy Joseph