ando@sys-net.it wrote:
I couldn't reproduce with a test (mostly unloaded) slapd. Since back-monitor dynamically builds the results based on the activity of slapd, the root cause could be related to the type of activity your slapd is doing (e.g. active connections, running operations and so).
I don't have a FreeBSD at hand right now, could you post a "thread apply all bt" from gdb? I might need to ask for further core inspection with gdb.
The tarball he posted has more information. You can see from the debug output that the first search succeeds and the second fails. It's failing while preparing the cn=Tasklist entry for output. In the first search, it shows that the BDB checkpoint task is running. Very likely it's not running in the second search, and the cn=Tasklist entry has been corrupted in the subsequent update. However I haven't gotten far enough to see how any corruption could happen or reproduce it. If you can pick it up from these clues, I'll get back to other work...