Richard Silverman wrote:

FYI: we have just observed another slapd deadlock with the same signature as the older one I indicated above, rather than the newer one which started this thread (all worker threads blocked on condition waits for database rather than network access). The F5 load balancer is now not involved. Again, this is RHEL 6.3 using this package:

openldap-servers-2.4.23-26.el6_3.2.x86_64

I am including a stack dump and gdb trace of all threads below.

This is most likely ITS#7222, your release is too old to contain the fix for this.