Merge pull request #1302 from rabbitmq/stable-gm-mem-usage-during-constant-redelivery

Stable GM memory usage during constant redelivery

Author: michaelklishin

src/gm.erl

@@ -395,9 +395,8 @@
 
 -define(GROUP_TABLE, gm_group).
 -define(MAX_BUFFER_SIZE, 100000000). %% 100MB
--define(HIBERNATE_AFTER_MIN, 1000).
--define(DESIRED_HIBERNATE, 10000).
 -define(BROADCAST_TIMER, 25).
+-define(FORCE_GC_TIMER, 250).
 -define(VERSION_START, 0).
 -define(SETS, ordsets).
 -define(DICT, orddict).
@@ -416,6 +415,7 @@
           broadcast_buffer,
           broadcast_buffer_sz,
           broadcast_timer,
+          force_gc_timer,
           txn_executor,
           shutting_down
         }).
@@ -508,7 +508,8 @@ table_definitions() ->
     [{Name, [?TABLE_MATCH | Attributes]}].
 
 start_link(GroupName, Module, Args, TxnFun) ->
-    gen_server2:start_link(?MODULE, [GroupName, Module, Args, TxnFun], []).
+    gen_server2:start_link(?MODULE, [GroupName, Module, Args, TxnFun],
+                       [{spawn_opt, [{fullsweep_after, 0}]}]).
 
 leave(Server) ->
     gen_server2:cast(Server, leave).
@@ -551,9 +552,9 @@ init([GroupName, Module, Args, TxnFun]) ->
                   broadcast_buffer    = [],
                   broadcast_buffer_sz = 0,
                   broadcast_timer     = undefined,
+                  force_gc_timer      = undefined,
                   txn_executor        = TxnFun,
-                  shutting_down       = false }, hibernate,
-     {backoff, ?HIBERNATE_AFTER_MIN, ?HIBERNATE_AFTER_MIN, ?DESIRED_HIBERNATE}}.
+                  shutting_down       = false }}.
 
 
 handle_call({confirmed_broadcast, _Msg}, _From,
@@ -708,6 +709,10 @@ handle_cast(leave, State) ->
     {stop, normal, State}.
 
 
+handle_info(force_gc, State) ->
+    garbage_collect(),
+    noreply(State #state { force_gc_timer = undefined });
+
 handle_info(flush, State) ->
     noreply(
       flush_broadcast_buffer(State #state { broadcast_timer = undefined }));
@@ -883,14 +888,24 @@ handle_msg({activity, _NotLeft, _Activity}, State) ->
 
 
 noreply(State) ->
-    {noreply, ensure_broadcast_timer(State), flush_timeout(State)}.
+    {noreply, ensure_timers(State), flush_timeout(State)}.
 
 reply(Reply, State) ->
-    {reply, Reply, ensure_broadcast_timer(State), flush_timeout(State)}.
+    {reply, Reply, ensure_timers(State), flush_timeout(State)}.
+
+ensure_timers(State) ->
+    ensure_force_gc_timer(ensure_broadcast_timer(State)).
 
-flush_timeout(#state{broadcast_buffer = []}) -> hibernate;
+flush_timeout(#state{broadcast_buffer = []}) -> infinity;
 flush_timeout(_)                             -> 0.
 
+ensure_force_gc_timer(State = #state { force_gc_timer = TRef })
+  when is_reference(TRef) ->
+    State;
+ensure_force_gc_timer(State = #state { force_gc_timer = undefined }) ->
+    TRef = erlang:send_after(?FORCE_GC_TIMER, self(), force_gc),
+    State #state { force_gc_timer = TRef }.
+
 ensure_broadcast_timer(State = #state { broadcast_buffer = [],
                                         broadcast_timer  = undefined }) ->
     State;
@@ -958,8 +973,7 @@ flush_broadcast_buffer(State = #state { self             = Self,
                       end, Self, MembersState),
     State #state { members_state       = MembersState1,
                    broadcast_buffer    = [],
-                   broadcast_buffer_sz = 0}.
-
+                   broadcast_buffer_sz = 0 }.
 
 %% ---------------------------------------------------------------------------
 %% View construction and inspection