Do these messages in the LDAP log on OSX Mavericks Server mean anything?
I found an entry in a thread on OpenLDAP.org's lists in which the commenter says that this is normal for BDB.

This is a normal occurrence in BerkeleyDB and does not indicate an
actual  error. The bdb/hdb backend code automatically retries when a
BDB deadlock is  reported.
Howard Chu, Chief Architect, OpenLDAP

(Source: https://www.openldap.org/lists/openldap-bugs/201409/msg00057.html)
I have been chasing the same error for the better part of a week, and a lot of people report this error for many different versions of macOS/MacOS and Linux, so it seems... normal, maybe?
Hope that helps.
/Bill