ovsdb-server: Report time since last connect and disconnect for each manager.

Only the time connected (if connected) or disconnected (if disconnected) is
currently reported for each manager. Change to reporting both in seconds since
the last connect and disconnect events respectively. An empty value indicates
no previous connection or disconnection.

This can help diagnose certain connectivity problems, e.g. flapping.

Requested-by: Peter Balland <peter@nicira.com>
Bug #4833.

1 files changed, 16 insertions, 18 deletions

diff --git a/python/ovs/reconnect.py b/python/ovs/reconnect.py
index 3445245db..49c7a094c 100644
--- a/python/ovs/reconnect.py
+++ b/python/ovs/reconnect.py
@@ -145,8 +145,8 @@ class Reconnect(object):
         self.state_entered = now
         self.backoff = 0
         self.last_received = now
-        self.last_connected = now
-        self.last_disconnected = now
+        self.last_connected = None
+        self.last_disconnected = None
         self.max_tries = None
 
         self.creation_time = now
@@ -529,23 +529,21 @@ class Reconnect(object):
         False otherwise."""
         return self.state.is_connected
 
-    def get_connection_duration(self, now):
-        """Returns the number of milliseconds for which this FSM has been
-        continuously connected to its peer.  (If this FSM is not currently
-        connected, this is 0.)"""
-        if self.is_connected():
+    def get_last_connect_elapsed(self, now):
+        """Returns the number of milliseconds since 'fsm' was last connected
+        to its peer. Returns None if never connected."""
+        if self.last_connected:
             return now - self.last_connected
         else:
-            return 0
+            return None
 
-    def get_disconnect_duration(self, now):
-        """Returns the number of milliseconds for which this FSM has been
-        continuously disconnected from its peer.  (If this FSM is not currently
-        connected, this is 0.)"""
-        if not self.is_connected():
+    def get_last_disconnect_elapsed(self, now):
+        """Returns the number of milliseconds since 'fsm' was last disconnected
+        from its peer. Returns None if never disconnected."""
+        if self.last_disconnected:
             return now - self.last_disconnected
         else:
-            return 0
+            return None
 
     def get_stats(self, now):
         class Stats(object):
@@ -558,10 +556,10 @@ class Reconnect(object):
         stats.backoff = self.backoff
         stats.seqno = self.seqno
         stats.is_connected = self.is_connected()
-        stats.current_connection_duration = self.get_connection_duration(now)
-        stats.current_disconnect_duration = self.get_disconnect_duration(now)
-        stats.total_connected_duration = (stats.current_connection_duration +
-                                          self.total_connected_duration)
+        stats.msec_since_connect = self.get_last_connect_elapsed(now)
+        stats.msec_since_disconnect = self.get_last_disconnect_elapsed(now)
+        stats.total_connected_duration = self.total_connected_duration + \
+            (self.get_last_connect_elapsed(now) if self.is_connected() else 0)
         stats.n_attempted_connections = self.n_attempted_connections
         stats.n_successful_connections = self.n_successful_connections
         stats.state = self.state.name