ctdb-scripts: Enhancements to hung script debugging
* Add stack dumps for "interesting" processes that sometimes get
stuck, so try to print stack traces for them if they appear in the
pstree output.
* Add new configuration variables CTDB_DEBUG_HUNG_SCRIPT_LOGFILE and
CTDB_DEBUG_HUNG_SCRIPT_STACKPAT. These are primarily for testing
but the latter may be useful for live debugging.
* Load CTDB configuration so that above configuration variables can be
set/changed without restarting ctdbd.
Add a test that tries to ensure that all of this is working.
Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>