Merge branch 'uw/mnesia-overload' into dev

* uw/mnesia-overload:
  Enable continuous monitoring of mnesia overload status

3 files changed, 84 insertions, 22 deletions

diff --git a/lib/mnesia/src/mnesia_controller.erl b/lib/mnesia/src/mnesia_controller.erl
index 95589e7a3a..0298b382a6 100644
--- a/lib/mnesia/src/mnesia_controller.erl
+++ b/lib/mnesia/src/mnesia_controller.erl
@@ -1849,17 +1849,20 @@ reply(ReplyTo, Reply) ->
 add_worker(Worker = #dump_log{}, State) ->
     InitBy = Worker#dump_log.initiated_by,
     Queue = State#state.dumper_queue,
-    case lists:keymember(InitBy, #dump_log.initiated_by, Queue) of
-	true when Worker#dump_log.opt_reply_to == undefined ->
-	    %% The same threshold has been exceeded again,
-	    %% before we have had the possibility to
-	    %% process the older one.
-	    DetectedBy = {dump_log, InitBy},
-	    Event = {mnesia_overload, DetectedBy},
-	    mnesia_lib:report_system_event(Event);
-	_ ->
-	    ignore
-    end,
+    Status =
+        case lists:keymember(InitBy, #dump_log.initiated_by, Queue) of
+            true when Worker#dump_log.opt_reply_to == undefined ->
+                %% The same threshold has been exceeded again,
+                %% before we have had the possibility to
+                %% process the older one.
+                DetectedBy = {dump_log, InitBy},
+                Event = {mnesia_overload, DetectedBy},
+                mnesia_lib:report_system_event(Event),
+                true;
+            _ ->
+                false
+        end,
+    mnesia_recover:log_dump_overload(Status),
     Queue2 = Queue ++ [Worker],
     State2 = State#state{dumper_queue = Queue2},
     opt_start_worker(State2);
diff --git a/lib/mnesia/src/mnesia_lib.erl b/lib/mnesia/src/mnesia_lib.erl
index dba808e66e..3da3dd2f5c 100644
--- a/lib/mnesia/src/mnesia_lib.erl
+++ b/lib/mnesia/src/mnesia_lib.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 1996-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 1996-2010. All Rights Reserved.
+%%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 %%
 
@@ -113,6 +113,9 @@
 	 mkcore/1,
 	 not_active_here/1,
 	 other_val/2,
+         overload_read/0,
+         overload_read/1,
+         overload_set/2,
 	 pad_name/3,
 	 random_time/2,
 	 read_counter/1,
@@ -551,6 +554,33 @@ cs_to_nodes(Cs) ->
     Cs#cstruct.disc_only_copies ++
     Cs#cstruct.disc_copies ++
     Cs#cstruct.ram_copies.
+
+overload_types() ->
+    [mnesia_tm, mnesia_dump_log].
+
+valid_overload_type(T) ->
+    case lists:member(T, overload_types()) of
+        false ->
+            erlang:error(bad_type);
+        true ->
+            true
+    end.
+
+overload_set(Type, Bool) when is_boolean(Bool) ->
+    valid_overload_type(Type),
+    set({overload, Type}, Bool).
+
+overload_read() ->
+    [{T, overload_read(T)} || T <- overload_types()].
+
+overload_read(T) ->
+    case ?catch_val({overload, T}) of
+        {'EXIT',_} ->
+            valid_overload_type(T),
+            false;
+        Flag when is_boolean(Flag) ->
+            Flag
+    end.
  
 dist_coredump() ->
     dist_coredump(all_nodes()).
diff --git a/lib/mnesia/src/mnesia_recover.erl b/lib/mnesia/src/mnesia_recover.erl
index 6c53c2e752..0ca7bf3f7f 100644
--- a/lib/mnesia/src/mnesia_recover.erl
+++ b/lib/mnesia/src/mnesia_recover.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 1997-2010. All Rights Reserved.
+%%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 %%
 
@@ -36,6 +36,7 @@
 	 incr_trans_tid_serial/0,
 	 init/0,
 	 log_decision/1,
+         log_dump_overload/1,
 	 log_master_nodes/3,
 	 log_mnesia_down/1,
 	 log_mnesia_up/1,
@@ -70,6 +71,7 @@
 		unclear_decision,
 		unclear_waitfor,
 		tm_queue_len = 0,
+                log_dump_overload = false,
 		initiated = false,
 		early_msgs = []
 	       }).
@@ -277,6 +279,9 @@ mnesia_down(Node) ->
 	    cast({mnesia_down, Node})
     end.
 
+log_dump_overload(Flag) when is_boolean(Flag) ->
+    cast({log_dump_overload, Flag}).
+
 log_master_nodes(Args, UseDir, IsRunning) ->
     if
 	IsRunning == yes ->
@@ -818,6 +823,12 @@ handle_cast({announce_all, Nodes}, State) ->
     announce_all(Nodes),
     {noreply, State};
 
+handle_cast({log_dump_overload, Flag}, State) when is_boolean(Flag) ->
+    Prev = State#state.log_dump_overload,
+    Overload = Prev orelse Flag,
+    mnesia_lib:overload_set(mnesia_dump_log, Overload),
+    {noreply, State#state{log_dump_overload = Flag}};
+
 handle_cast(Msg, State) ->
     error("~p got unexpected cast: ~p~n", [?MODULE, Msg]),
     {noreply, State}.
@@ -851,12 +862,14 @@ handle_info(check_overload, S) ->
 		Len > Threshold, Prev > Threshold ->
 		    What = {mnesia_tm, message_queue_len, [Prev, Len]},
 		    mnesia_lib:report_system_event({mnesia_overload, What}),
+                    mnesia_lib:overload_set(mnesia_tm, true),
 		    {noreply, S#state{tm_queue_len = 0}};
 		
 		Len > Threshold ->
 		    {noreply, S#state{tm_queue_len = Len}};
 		
 		true ->
+                    mnesia_lib:overload_set(mnesia_tm, false),
 		    {noreply, S#state{tm_queue_len = 0}}
 	    end;
 	undefined ->
@@ -905,7 +918,23 @@ terminate(Reason, State) ->
 %% Purpose: Upgrade process when its code is to be changed
 %% Returns: {ok, NewState}
 %%----------------------------------------------------------------------
-code_change(_OldVsn, State, _Extra) ->
+code_change(_OldVsn, {state,
+                      Supervisor,
+                      Unclear_pid,
+                      Unclear_decision,
+                      Unclear_waitfor,
+                      Tm_queue_len,
+                      Initiated,
+                      Early_msgs
+                     }, _Extra) ->
+    {ok, #state{supervisor = Supervisor,
+                unclear_pid = Unclear_pid,
+                unclear_decision = Unclear_decision,
+                unclear_waitfor = Unclear_waitfor,
+                tm_queue_len = Tm_queue_len,
+                initiated = Initiated,
+                early_msgs = Early_msgs}};
+code_change(_OldVsn, #state{} = State, _Extra) ->
     {ok, State}.
 
 %%%----------------------------------------------------------------------