1 files changed, 61 insertions, 0 deletions
diff --git a/ctdb/config/debug-hung-script.sh b/ctdb/config/debug-hung-script.sh
new file mode 100755
index 0000000..c1ac0f1
--- /dev/null
+++ b/ctdb/config/debug-hung-script.sh
@@ -0,0 +1,61 @@
+#!/bin/sh
+
+# This script only works on Linux.  Please modify (and submit patches)
+# for other operating systems.
+
+[ -n "$CTDB_BASE" ] || \
+	CTDB_BASE=$(d=$(dirname "$0") && cd -P "$d" && echo "$PWD")
+
+. "${CTDB_BASE}/functions"
+
+load_script_options
+
+# Testing hook
+if [ -n "$CTDB_DEBUG_HUNG_SCRIPT_LOGFILE" ] ; then
+    tmp="${CTDB_DEBUG_HUNG_SCRIPT_LOGFILE}.part"
+    exec >>"$tmp" 2>&1
+fi
+
+(
+    # No use running several of these in parallel if, say, "releaseip"
+    # event hangs for multiple IPs.  In that case the output would be
+    # interleaved in the log and would just be confusing.
+    flock --wait 2 9 || exit 1
+
+    echo "===== Start of hung script debug for PID=\"$1\", event=\"$2\" ====="
+
+    echo "pstree -p -a ${1}:"
+    out=$(pstree -p -a "$1")
+    echo "$out"
+
+    # Check for processes matching a regular expression and print
+    # stack staces.  This could help confirm that certain processes
+    # are stuck in certain places such as the cluster filesystem.  The
+    # regexp must separate items with "|" and must not contain
+    # parentheses.  The default pattern can be replaced for testing.
+    default_pat='exportfs|rpcinfo'
+    pat="${CTDB_DEBUG_HUNG_SCRIPT_STACKPAT:-${default_pat}}"
+    echo "$out" |
+    sed -r -n "s@.*-(.*(${pat}).*),([0-9]*).*@\\3 \\1@p" |
+    while read pid name ; do
+	trace=$(cat "/proc/${pid}/stack" 2>/dev/null)
+	# No! Checking the exit code afterwards is actually clearer...
+	# shellcheck disable=SC2181
+	if [ $? -eq 0 ] ; then
+	    echo "---- Stack trace of interesting process ${pid}[${name}] ----"
+	    echo "$trace"
+	fi
+    done
+
+    if [ "$2" != "init" ] ; then
+	echo "---- ctdb scriptstatus ${2}: ----"
+	$CTDB scriptstatus "$2"
+    fi
+
+    echo "===== End of hung script debug for PID=\"$1\", event=\"$2\" ====="
+
+    if [ -n "$CTDB_DEBUG_HUNG_SCRIPT_LOGFILE" ] ; then
+	mv "$tmp" "$CTDB_DEBUG_HUNG_SCRIPT_LOGFILE"
+    fi
+
+) 9>"${CTDB_SCRIPT_VARDIR}/debug-hung-script.lock"