(ITS#5508) slapd process consumes all of CPU

[whm@stanford.edu]

Full_Name: Bill MacAllister
Version: 2.3.41-1su2
OS: debian etch kernel 2.6.18-4-amd64
URL: http://www.stanford.edu/~whm/ldap-test1-bt.txt
Submission from: (NULL) (171.64.19.165)


The slapd process will sometimes consume all of available CPU.  We observed this
when we upgraded our production servers from 2.3.35-2su2 to 2.3.41-1su2.  The
problem was bad enough that we downgraded the production servers to 2.3.35-2su2.
 We have been trying to provoke the problem in our test environment and have not
been successful in making it happen on demand.  Today, we noticed that one of
our test servers went completely CPU bound.  I took a backtrace.  It is
available at the URL below.  The interesting thing about the problem is that
although top shows a pinned CPU and a high load the server is still responsive
and continues to answer LDAP searches.  The test server that exhibits the
problem is still CPU bound and has been for 2-3 hours now.  We will leave this
server in this state in case there is other information that we should harvest
in resolving the problem.