[logger] Change registered name of built-in handlers and use TID for mode table

6 files changed, 232 insertions, 170 deletions

diff --git a/lib/kernel/src/logger_disk_log_h.erl b/lib/kernel/src/logger_disk_log_h.erl
index 00643b6a84..ba90fefcd3 100644
--- a/lib/kernel/src/logger_disk_log_h.erl
+++ b/lib/kernel/src/logger_disk_log_h.erl
@@ -63,7 +63,8 @@ start_link(Name, Config, HandlerState) ->
 
 sync(Name) when is_atom(Name) ->
     try
-        gen_server:call(Name, disk_log_sync, ?DEFAULT_CALL_TIMEOUT)
+        gen_server:call(?name_to_reg_name(?MODULE,Name),
+                        disk_log_sync, ?DEFAULT_CALL_TIMEOUT)
     catch
         _:{timeout,_} -> {error,handler_busy}
     end;
@@ -79,7 +80,8 @@ sync(Name) ->
 
 info(Name) when is_atom(Name) ->
     try
-        gen_server:call(Name, info, ?DEFAULT_CALL_TIMEOUT)
+        gen_server:call(?name_to_reg_name(?MODULE,Name),
+                        info, ?DEFAULT_CALL_TIMEOUT)
     catch
         _:{timeout,_} -> {error,handler_busy}
     end;
@@ -94,7 +96,8 @@ info(Name) ->
 
 reset(Name) when is_atom(Name) ->
     try
-        gen_server:call(Name, reset, ?DEFAULT_CALL_TIMEOUT)
+        gen_server:call(?name_to_reg_name(?MODULE,Name),
+                        reset, ?DEFAULT_CALL_TIMEOUT)
     catch
         _:{timeout,_} -> {error,handler_busy}
     end;      
@@ -117,10 +120,10 @@ adding_handler(#{id:=Name}=Config) ->
             case logger_h_common:overload_levels_ok(HState) of
                 true ->
                     case start(Name, Config1, HState) of
-                        ok ->
+                        {ok,Config2} ->
                             %% Make sure wait_for_buffer is not stored, so we
                             %% won't hang and wait for buffer on a restart
-                            {ok, maps:remove(wait_for_buffer,Config1)};
+                            {ok, maps:remove(wait_for_buffer,Config2)};
                         Error ->
                             Error
                     end;
@@ -136,13 +139,18 @@ adding_handler(#{id:=Name}=Config) ->
 
 %%%-----------------------------------------------------------------
 %%% Updating handler config
-changing_config(OldConfig=#{id:=Name, disk_log_opts:=DLOpts},
+changing_config(OldConfig=#{id:=Name, disk_log_opts:=DLOpts, ?MODULE:=HConfig},
                 NewConfig=#{id:=Name, disk_log_opts:=DLOpts}) ->
     case check_config(changing, NewConfig) of
-        Result = {ok,NewConfig1} ->
-            try gen_server:call(Name, {change_config,OldConfig,NewConfig1},
+        {ok,NewConfig1 = #{?MODULE:=NewHConfig}} ->
+            #{handler_pid:=HPid,
+              mode_tab:=ModeTab} = HConfig,
+            NewHConfig1 = NewHConfig#{handler_pid=>HPid,
+                                      mode_tab=>ModeTab},
+            NewConfig2 = NewConfig1#{?MODULE=>NewHConfig1},
+            try gen_server:call(HPid, {change_config,OldConfig,NewConfig2},
                                 ?DEFAULT_CALL_TIMEOUT) of
-                ok      -> Result;
+                ok      -> {ok,NewConfig2};
                 HError  -> HError
             catch
                 _:{timeout,_} -> {error,handler_busy}
@@ -225,12 +233,12 @@ removing_handler(#{id:=Name}) ->
 
 %%%-----------------------------------------------------------------
 %%% Get buffer when swapping from simple handler
-swap_buffer(Name,Buffer) ->
-    case whereis(Name) of
+swap_buffer(Name, Buffer) ->
+    case whereis(?name_to_reg_name(?MODULE,Name)) of
         undefined ->
             ok;
-        _ ->
-            Name ! {buffer,Buffer}
+        Pid ->
+            Pid ! {buffer,Buffer}
     end.
 
 %%%-----------------------------------------------------------------
@@ -239,21 +247,22 @@ swap_buffer(Name,Buffer) ->
       LogEvent :: logger:log_event(),
       Config :: logger:config().
 
-log(LogEvent,Config=#{id:=Name}) ->
+log(LogEvent, Config = #{id := Name,
+                         ?MODULE := #{handler_pid := HPid,
+                                      mode_tab := ModeTab}}) ->
     %% if the handler has crashed, we must drop this request
     %% and hope the handler restarts so we can try again
-    true = is_pid(whereis(Name)),
-    Bin = logger_h_common:log_to_binary(LogEvent,Config),
-    logger_h_common:call_cast_or_drop(Name, Bin).
-
+    true = is_process_alive(HPid),
+    Bin = logger_h_common:log_to_binary(LogEvent, Config),
+    logger_h_common:call_cast_or_drop(Name, HPid, ModeTab, Bin).
 
 %%%===================================================================
 %%% gen_server callbacks
 %%%===================================================================
 
-init([Name, Config = #{disk_log_opts := LogOpts},
+init([Name, Config = #{?MODULE := HConfig, disk_log_opts := LogOpts},
       State = #{dl_sync_int := DLSyncInt}]) ->
-    register(Name, self()),
+    register(?name_to_reg_name(?MODULE,Name), self()),
     process_flag(trap_exit, true),
     process_flag(message_queue_data, off_heap),
 
@@ -262,25 +271,36 @@ init([Name, Config = #{disk_log_opts := LogOpts},
 
     case open_disk_log(Name, LogOpts) of
         ok ->
-            catch ets:new(Name, [public, named_table]),
-            ?set_mode(Name, async),
-            proc_lib:init_ack({ok,self()}),
-            T0 = ?timestamp(),
-            State1 =
-                ?merge_with_stats(State#{id => Name,
-                                         mode => async,
-                                         dl_sync => DLSyncInt,
-                                         log_opts => LogOpts,
-                                         last_qlen => 0,
-                                         last_log_ts => T0,
-                                         burst_win_ts => T0,
-                                         burst_msg_count => 0,
-                                         last_op => sync,
-                                         prev_log_result => ok,
-                                         prev_sync_result => ok,
-                                         prev_disk_log_info => undefined}),
-            gen_server:cast(self(), repeated_disk_log_sync),
-            enter_loop(Config, State1);
+            try ets:new(Name, [public]) of
+                ModeTab ->
+                    ?set_mode(ModeTab, async),
+                    T0 = ?timestamp(),
+                    State1 =
+                        ?merge_with_stats(State#{
+                                            id => Name,
+                                            mode_tab => ModeTab,
+                                            mode => async,
+                                            dl_sync => DLSyncInt,
+                                            log_opts => LogOpts,
+                                            last_qlen => 0,
+                                            last_log_ts => T0,
+                                            burst_win_ts => T0,
+                                            burst_msg_count => 0,
+                                            last_op => sync,
+                                            prev_log_result => ok,
+                                            prev_sync_result => ok,
+                                            prev_disk_log_info => undefined}),
+                    Config1 =
+                        Config#{?MODULE => HConfig#{handler_pid => self(),
+                                                    mode_tab => ModeTab}},
+                    proc_lib:init_ack({ok,self(),Config1}),
+                    gen_server:cast(self(), repeated_disk_log_sync),
+                    enter_loop(Config1, State1)
+            catch
+                _:Error ->
+                    logger_h_common:error_notify({open_disk_log,Name,Error}),
+                    proc_lib:init_ack(Error)
+            end;
         Error ->
             logger_h_common:error_notify({open_disk_log,Name,Error}),
             proc_lib:init_ack(Error)
@@ -477,8 +497,8 @@ start(Name, Config, HandlerState) ->
           type     => worker,
           modules  => [?MODULE]},
     case supervisor:start_child(logger_sup, LoggerDLH) of
-        {ok,_} ->
-            ok;
+        {ok,_Pid,Config1} ->
+            {ok,Config1};
         Error ->
             Error
     end.
@@ -486,16 +506,16 @@ start(Name, Config, HandlerState) ->
 %%%-----------------------------------------------------------------
 %%% Stop and remove the handler.
 stop(Name) ->
-    case whereis(Name) of
+    case whereis(?name_to_reg_name(?MODULE,Name)) of
         undefined ->
             ok;
-        _ ->
+        Pid ->
             %% We don't want to do supervisor:terminate_child here
             %% since we need to distinguish this explicit stop from a
             %% system termination in order to avoid circular attempts
             %% at removing the handler (implying deadlocks and
             %% timeouts).
-            _ = gen_server:call(Name,stop),
+            _ = gen_server:call(Pid, stop),
             _ = supervisor:delete_child(logger_sup, Name),
             ok
     end.
@@ -530,7 +550,7 @@ do_log(Bin, CallOrCast, State = #{id:=Name, mode := _Mode0}) ->
 
 %% this function is called by do_log/3 after an overload check
 %% has been performed, where QLen > FlushQLen
-flush(Name, _QLen0, T1, State=#{last_log_ts := _T0}) ->
+flush(_Name, _QLen0, T1, State=#{last_log_ts := _T0, mode_tab := ModeTab}) ->
     %% flush messages in the mailbox (a limited number in
     %% order to not cause long delays)
     _NewFlushed = logger_h_common:flush_log_requests(?FLUSH_MAX_N),
@@ -539,20 +559,21 @@ flush(Name, _QLen0, T1, State=#{last_log_ts := _T0}) ->
     %% handler will be scheduled out often and the mailbox could
     %% grow very large, so we'd better check the queue again here
     {_,_QLen1} = process_info(self(), message_queue_len),
-    ?observe(Name,{max_qlen,_QLen1}),
+    ?observe(_Name,{max_qlen,_QLen1}),
 
     %% Add 1 for the current log request
-    ?observe(Name,{flushed,_NewFlushed+1}),
+    ?observe(_Name,{flushed,_NewFlushed+1}),
 
     State1 = ?update_max_time(?diff_time(T1,_T0),State),
     {dropped,?update_other(flushed,FLUSHED,_NewFlushed,
-                           State1#{mode => ?set_mode(Name,async),
+                           State1#{mode => ?set_mode(ModeTab,async),
                                    last_qlen => 0,
                                    last_log_ts => T1})}.
 
 %% this function is called to write to disk_log
 write(Name, Mode, T1, Bin, _CallOrCast,
-      State = #{dl_sync := DLSync,
+      State = #{mode_tab := ModeTab,
+                dl_sync := DLSync,
                 dl_sync_int := DLSyncInt,
                 last_qlen := LastQLen,
                 last_log_ts := T0}) ->
@@ -589,7 +610,7 @@ write(Name, Mode, T1, Bin, _CallOrCast,
     {Mode1,BurstMsgCount1,State2} =
         if (LastQLen1 < ?FILESYNC_OK_QLEN) andalso
            (Time > ?IDLE_DETECT_TIME_USEC) ->
-                {?change_mode(Name,Mode,async), 0, disk_log_sync(Name,State1)};
+                {?change_mode(ModeTab,Mode,async), 0, disk_log_sync(Name,State1)};
            true ->
                 {Mode, BurstMsgCount,State1}
         end,
diff --git a/lib/kernel/src/logger_h_common.erl b/lib/kernel/src/logger_h_common.erl
index 336398cd4a..73a5b27ea1 100644
--- a/lib/kernel/src/logger_h_common.erl
+++ b/lib/kernel/src/logger_h_common.erl
@@ -24,7 +24,7 @@
 
 -export([log_to_binary/2,
          check_common_config/1,
-         call_cast_or_drop/2,
+         call_cast_or_drop/4,
          check_load/1,
          limit_burst/1,
          kill_if_choked/4,
@@ -84,6 +84,10 @@ try_format(Log,Formatter,FormatterConfig) ->
 
 %%%-----------------------------------------------------------------
 %%% Check that the configuration term is valid
+check_common_config({mode_tab,_Tid}) ->
+    valid;
+check_common_config({handler_pid,Pid}) when is_pid(Pid) ->
+    valid;
 check_common_config({toggle_sync_qlen,N}) when is_integer(N) ->
     valid;
 check_common_config({drop_new_reqs_qlen,N}) when is_integer(N) ->
@@ -116,16 +120,16 @@ check_common_config(_) ->
 
 %%%-----------------------------------------------------------------
 %%% Overload Protection
-call_cast_or_drop(Name, Bin) ->
+call_cast_or_drop(_Name, HandlerPid, ModeTab, Bin) ->
     %% If the handler process is getting overloaded, the log request
     %% will be synchronous instead of asynchronous (slows down the
     %% logging tempo of a process doing lots of logging. If the
     %% handler is choked, drop mode is set and no request will be sent.
-    try ?get_mode(Name) of
+    try ?get_mode(ModeTab) of
         async ->
-            gen_server:cast(Name, {log,Bin});
+            gen_server:cast(HandlerPid, {log,Bin});
         sync ->
-            try gen_server:call(Name, {log,Bin}, ?DEFAULT_CALL_TIMEOUT) of
+            try gen_server:call(HandlerPid, {log,Bin}, ?DEFAULT_CALL_TIMEOUT) of
                 %% if return value from call == dropped, the
                 %% message has been flushed by handler and should
                 %% therefore not be counted as dropped in stats
@@ -133,28 +137,28 @@ call_cast_or_drop(Name, Bin) ->
                 dropped -> ok
             catch
                 _:{timeout,_} ->
-                    ?observe(Name,{dropped,1})
+                    ?observe(_Name,{dropped,1})
             end;
         drop ->
-            ?observe(Name,{dropped,1})
+            ?observe(_Name,{dropped,1})
     catch
         %% if the ETS table doesn't exist (maybe because of a
         %% handler restart), we can only drop the request
-        _:_ -> ?observe(Name,{dropped,1})
+        _:_ -> ?observe(_Name,{dropped,1})
     end,
     ok.
 
 handler_exit(_Name, Reason) ->
     exit(Reason).
 
-check_load(State = #{id:=Name, mode := Mode,
+check_load(State = #{id:=_Name, mode_tab := ModeTab, mode := Mode,
                      toggle_sync_qlen := ToggleSyncQLen,
                      drop_new_reqs_qlen := DropNewQLen,
                      flush_reqs_qlen := FlushQLen}) ->
     {_,Mem} = process_info(self(), memory),
-    ?observe(Name,{max_mem,Mem}),
+    ?observe(_Name,{max_mem,Mem}),
     {_,QLen} = process_info(self(), message_queue_len),
-    ?observe(Name,{max_qlen,QLen}),
+    ?observe(_Name,{max_qlen,QLen}),
     %% When the handler process gets scheduled in, it's impossible
     %% to predict the QLen. We could jump "up" arbitrarily from say
     %% async to sync, async to drop, sync to flush, etc. However, when
@@ -171,11 +175,11 @@ check_load(State = #{id:=Name, mode := Mode,
                 %% be dropped on the client side (never sent get to
                 %% the handler).
                 IncDrops = if Mode == drop -> 0; true -> 1 end,
-                {?change_mode(Name, Mode, drop), IncDrops,0};
+                {?change_mode(ModeTab, Mode, drop), IncDrops,0};
             QLen >= ToggleSyncQLen ->
-                {?change_mode(Name, Mode, sync), 0,0};
+                {?change_mode(ModeTab, Mode, sync), 0,0};
             true ->
-                {?change_mode(Name, Mode, async), 0,0}
+                {?change_mode(ModeTab, Mode, async), 0,0}
         end,
     State1 = ?update_other(drops,DROPS,_NewDrops,State),
     {Mode1, QLen, Mem,
diff --git a/lib/kernel/src/logger_h_common.hrl b/lib/kernel/src/logger_h_common.hrl
index ed365ce6eb..e4d3431468 100644
--- a/lib/kernel/src/logger_h_common.hrl
+++ b/lib/kernel/src/logger_h_common.hrl
@@ -77,29 +77,30 @@
 -define(DISK_LOG_MAX_NO_BYTES, 1048576).
 
 %%%-----------------------------------------------------------------
+%%% Utility macros
+
+-define(name_to_reg_name(MODULE,Name),
+        list_to_atom(lists:concat([MODULE,"_",Name]))).
+
+%%%-----------------------------------------------------------------
 %%% Overload protection macros
 
 -define(timestamp(), erlang:monotonic_time(microsecond)).
 
--define(get_mode(HandlerName),
-        case ets:lookup(HandlerName, mode) of
-            [{mode,sync}] ->
-                case whereis(HandlerName)==self() of
-                    true -> async;
-                    _ -> sync
-                end;
+-define(get_mode(Tid),
+        case ets:lookup(Tid, mode) of
             [{mode,M}] -> M;
             _          -> async
         end).
 
--define(set_mode(HandlerName, M),
-        begin ets:insert(HandlerName, {mode,M}), M end).
+-define(set_mode(Tid, M),
+        begin ets:insert(Tid, {mode,M}), M end).
 
--define(change_mode(HandlerName, M0, M1),
+-define(change_mode(Tid, M0, M1),
         if M0 == M1 ->
                 M0;
            true ->
-                ets:insert(HandlerName, {mode,M1}),
+                ets:insert(Tid, {mode,M1}),
                 M1
         end).
 
@@ -124,7 +125,7 @@
 %%% slow down execution and therefore should not be include in code
 %%% to be officially released.
 
--define(TEST_HOOKS, true).
+%%-define(TEST_HOOKS, true).
 -ifdef(TEST_HOOKS).
   -define(TEST_HOOKS_TAB, logger_h_test_hooks).
 
diff --git a/lib/kernel/src/logger_std_h.erl b/lib/kernel/src/logger_std_h.erl
index 323f4f02e7..5ec9eced12 100644
--- a/lib/kernel/src/logger_std_h.erl
+++ b/lib/kernel/src/logger_std_h.erl
@@ -64,7 +64,8 @@ start_link(Name, Config, HandlerState) ->
 
 sync(Name) when is_atom(Name) ->
     try
-        gen_server:call(Name, filesync, ?DEFAULT_CALL_TIMEOUT)
+        gen_server:call(?name_to_reg_name(?MODULE,Name),
+                        filesync, ?DEFAULT_CALL_TIMEOUT)
     catch
         _:{timeout,_} -> {error,handler_busy}
     end;
@@ -80,7 +81,8 @@ sync(Name) ->
 
 info(Name) when is_atom(Name) ->
     try
-        gen_server:call(Name, info, ?DEFAULT_CALL_TIMEOUT)
+        gen_server:call(?name_to_reg_name(?MODULE,Name),
+                        info, ?DEFAULT_CALL_TIMEOUT)
     catch
         _:{timeout,_} -> {error,handler_busy}
     end;
@@ -95,7 +97,8 @@ info(Name) ->
 
 reset(Name) when is_atom(Name) ->
     try
-        gen_server:call(Name, reset, ?DEFAULT_CALL_TIMEOUT)
+        gen_server:call(?name_to_reg_name(?MODULE,Name),
+                        reset, ?DEFAULT_CALL_TIMEOUT)
     catch
         _:{timeout,_} -> {error,handler_busy}
     end;      
@@ -118,10 +121,10 @@ adding_handler(#{id:=Name}=Config) ->
             case logger_h_common:overload_levels_ok(HState) of
                 true ->
                     case start(Name, Config1, HState) of
-                        ok ->
+                        {ok,Config2} ->
                             %% Make sure wait_for_buffer is not stored, so we
                             %% won't hang and wait for buffer on a restart
-                            {ok, maps:remove(wait_for_buffer,Config1)};
+                            {ok, maps:remove(wait_for_buffer,Config2)};
                         Error ->
                             Error
                     end;
@@ -137,13 +140,16 @@ adding_handler(#{id:=Name}=Config) ->
 
 %%%-----------------------------------------------------------------
 %%% Updating handler config
-changing_config(OldConfig=#{id:=Name, ?MODULE:=#{type:=Type}},
+changing_config(OldConfig=#{id:=Name, ?MODULE:=HConfig},
                 NewConfig=#{id:=Name}) ->
+    #{type:=Type, handler_pid:=HPid, mode_tab:=ModeTab} = HConfig,
     MyConfig = maps:get(?MODULE, NewConfig, #{}),
     case maps:get(type, MyConfig, Type) of
         Type ->
-            MyConfig1 = MyConfig#{type=>Type},
-            changing_config1(Name, OldConfig,
+            MyConfig1 = MyConfig#{type=>Type,
+                                  handler_pid=>HPid,
+                                  mode_tab=>ModeTab},
+            changing_config1(HPid, OldConfig,
                              NewConfig#{?MODULE=>MyConfig1});
         _ ->
             {error,{illegal_config_change,OldConfig,NewConfig}}
@@ -151,10 +157,10 @@ changing_config(OldConfig=#{id:=Name, ?MODULE:=#{type:=Type}},
 changing_config(OldConfig, NewConfig) ->
     {error,{illegal_config_change,OldConfig,NewConfig}}.
 
-changing_config1(Name, OldConfig, NewConfig) ->
+changing_config1(HPid, OldConfig, NewConfig) ->
     case check_config(changing, NewConfig) of
         Result = {ok,NewConfig1} ->
-            try gen_server:call(Name, {change_config,OldConfig,NewConfig1},
+            try gen_server:call(HPid, {change_config,OldConfig,NewConfig1},
                                 ?DEFAULT_CALL_TIMEOUT) of
                 ok      -> Result;
                 HError  -> HError
@@ -209,12 +215,12 @@ removing_handler(#{id:=Name}) ->
 
 %%%-----------------------------------------------------------------
 %%% Get buffer when swapping from simple handler
-swap_buffer(Name,Buffer) ->
-    case whereis(Name) of
+swap_buffer(Name, Buffer) ->
+    case whereis(?name_to_reg_name(?MODULE,Name)) of
         undefined ->
             ok;
-        _ ->
-            Name ! {buffer,Buffer}
+        Pid ->
+            Pid ! {buffer,Buffer}
     end.
 
 %%%-----------------------------------------------------------------
@@ -223,20 +229,22 @@ swap_buffer(Name,Buffer) ->
       LogEvent :: logger:log_event(),
       Config :: logger:config().
 
-log(LogEvent,Config=#{id:=Name}) ->
+log(LogEvent, Config = #{id := Name,
+                         ?MODULE := #{handler_pid := HPid,
+                                      mode_tab := ModeTab}}) ->
     %% if the handler has crashed, we must drop this request
     %% and hope the handler restarts so we can try again
-    true = is_pid(whereis(Name)),
-    Bin = logger_h_common:log_to_binary(LogEvent,Config),
-    logger_h_common:call_cast_or_drop(Name, Bin).
+    true = is_process_alive(HPid),
+    Bin = logger_h_common:log_to_binary(LogEvent, Config),
+    logger_h_common:call_cast_or_drop(Name, HPid, ModeTab, Bin).
 
 %%%===================================================================
 %%% gen_server callbacks
 %%%===================================================================
 
-init([Name, Config,
-      State0 = #{type := Type, file_ctrl_sync_int := FileCtrlSyncInt}]) ->
-    register(Name, self()),
+init([Name, Config = #{?MODULE := HConfig},
+      State0 = #{type := Type, file_ctrl_sync_int := FileCtrlSyncInt}]) ->    
+    register(?name_to_reg_name(?MODULE,Name), self()),
     process_flag(trap_exit, true),
     process_flag(message_queue_data, off_heap),
 
@@ -245,21 +253,32 @@ init([Name, Config,
 
     case do_init(Name, Type) of
         {ok,InitState} ->
-            catch ets:new(Name, [public, named_table]),
-            ?set_mode(Name, async),
-            State = maps:merge(State0, InitState),
-            T0 = ?timestamp(),
-            State1 =
-                ?merge_with_stats(State#{mode => async,
-                                         file_ctrl_sync => FileCtrlSyncInt,
-                                         last_qlen => 0,
-                                         last_log_ts => T0,
-                                         last_op => sync,
-                                         burst_win_ts => T0,
-                                         burst_msg_count => 0}),
-            proc_lib:init_ack({ok,self()}),
-            gen_server:cast(self(), repeated_filesync),
-            enter_loop(Config, State1);
+            try ets:new(Name, [public]) of
+                ModeTab ->
+                    ?set_mode(ModeTab, async),
+                    State = maps:merge(State0, InitState),
+                    T0 = ?timestamp(),
+                    State1 =
+                        ?merge_with_stats(State#{
+                                            mode_tab => ModeTab,
+                                            mode => async,
+                                            file_ctrl_sync => FileCtrlSyncInt,
+                                            last_qlen => 0,
+                                            last_log_ts => T0,
+                                            last_op => sync,
+                                            burst_win_ts => T0,
+                                            burst_msg_count => 0}),
+                    Config1 =
+                        Config#{?MODULE => HConfig#{handler_pid => self(),
+                                                    mode_tab => ModeTab}},
+                    proc_lib:init_ack({ok,self(),Config1}),
+                    gen_server:cast(self(), repeated_filesync),
+                    enter_loop(Config1, State1)
+            catch
+                _:Error ->
+                    logger_h_common:error_notify({init_handler,Name,Error}),
+                    proc_lib:init_ack(Error)
+            end;
         Error ->
             logger_h_common:error_notify({init_handler,Name,Error}),
             proc_lib:init_ack(Error)
@@ -466,8 +485,8 @@ start(Name, Config, HandlerState) ->
           type     => worker,
           modules  => [?MODULE]},
     case supervisor:start_child(logger_sup, LoggerStdH) of
-        {ok,_Pid} ->
-            ok;
+        {ok,_Pid,Config1} ->
+            {ok,Config1};
         Error ->
             Error
     end.
@@ -475,16 +494,16 @@ start(Name, Config, HandlerState) ->
 %%%-----------------------------------------------------------------
 %%% Stop and remove the handler.
 stop(Name) ->
-    case whereis(Name) of
+    case whereis(?name_to_reg_name(?MODULE,Name)) of
         undefined ->
             ok;
-        _ ->
+        Pid ->
             %% We don't want to do supervisor:terminate_child here
             %% since we need to distinguish this explicit stop from a
             %% system termination in order to avoid circular attempts
             %% at removing the handler (implying deadlocks and
             %% timeouts).
-            _ = gen_server:call(Name,stop),
+            _ = gen_server:call(Pid, stop),
             _ = supervisor:delete_child(logger_sup, Name),
             ok
     end.
@@ -519,7 +538,7 @@ do_log(Bin, CallOrCast, State = #{id:=Name}) ->
 
 %% this clause is called by do_log/3 after an overload check
 %% has been performed, where QLen > FlushQLen
-flush(Name, _QLen0, T1, State=#{last_log_ts := _T0}) ->
+flush(_Name, _QLen0, T1, State=#{last_log_ts := _T0, mode_tab := ModeTab}) ->
     %% flush messages in the mailbox (a limited number in
     %% order to not cause long delays)
     _NewFlushed = logger_h_common:flush_log_requests(?FLUSH_MAX_N),
@@ -528,20 +547,21 @@ flush(Name, _QLen0, T1, State=#{last_log_ts := _T0}) ->
     %% handler will be scheduled out often and the mailbox could
     %% grow very large, so we'd better check the queue again here
     {_,_QLen1} = process_info(self(), message_queue_len),
-    ?observe(Name,{max_qlen,_QLen1}),
+    ?observe(_Name,{max_qlen,_QLen1}),
     
     %% Add 1 for the current log request
-    ?observe(Name,{flushed,_NewFlushed+1}),
+    ?observe(_Name,{flushed,_NewFlushed+1}),
  
     State1 = ?update_max_time(?diff_time(T1,_T0),State),
     {dropped,?update_other(flushed,FLUSHED,_NewFlushed,
-                           State1#{mode => ?set_mode(Name,async),
+                           State1#{mode => ?set_mode(ModeTab,async),
                                    last_qlen => 0,
                                    last_log_ts => T1})}.
 
 %% this clause is called to write to file
-write(Name, Mode, T1, Bin, _CallOrCast,
-      State = #{file_ctrl_pid := FileCtrlPid,
+write(_Name, Mode, T1, Bin, _CallOrCast,
+      State = #{mode_tab := ModeTab,
+                file_ctrl_pid := FileCtrlPid,
                 file_ctrl_sync := FileCtrlSync,
                 last_qlen := LastQLen,
                 last_log_ts := T0,
@@ -555,15 +575,15 @@ write(Name, Mode, T1, Bin, _CallOrCast,
     %% file writes so it can keep up with incoming messages
     {Result,LastQLen1} =
         if DoWrite, FileCtrlSync == 0 ->
-                ?observe(Name,{_CallOrCast,1}),
+                ?observe(_Name,{_CallOrCast,1}),
                 file_write_sync(FileCtrlPid, Bin, false),
                 {ok,element(2, process_info(self(), message_queue_len))};
            DoWrite ->
-                ?observe(Name,{_CallOrCast,1}),
+                ?observe(_Name,{_CallOrCast,1}),
                 file_write_async(FileCtrlPid, Bin),
                 {ok,LastQLen};
            not DoWrite ->
-                ?observe(Name,{flushed,1}),
+                ?observe(_Name,{flushed,1}),
                 {dropped,LastQLen}
         end,
     
@@ -585,7 +605,7 @@ write(Name, Mode, T1, Bin, _CallOrCast,
                     _File ->
                         file_ctrl_filesync_async(FileCtrlPid)
                 end,
-                {?change_mode(Name, Mode, async),0};
+                {?change_mode(ModeTab, Mode, async),0};
            true ->
                 {Mode,BurstMsgCount}
         end,
diff --git a/lib/kernel/test/logger_disk_log_h_SUITE.erl b/lib/kernel/test/logger_disk_log_h_SUITE.erl
index 2b5bbe6aed..e1b1f16414 100644
--- a/lib/kernel/test/logger_disk_log_h_SUITE.erl
+++ b/lib/kernel/test/logger_disk_log_h_SUITE.erl
@@ -107,10 +107,10 @@ start_stop_handler(_Config) ->
     ok = logger:add_handler(?MODULE, logger_disk_log_h, #{}),
     {error,{already_exist,?MODULE}} =
         logger:add_handler(?MODULE, logger_disk_log_h, #{}),
-    true = is_pid(whereis(?MODULE)),
+    true = is_pid(whereis(h_proc_name())),
     ok = logger:remove_handler(?MODULE),
     timer:sleep(500),
-    undefined = whereis(?MODULE).
+    undefined = whereis(h_proc_name()).
 start_stop_handler(cleanup, _Config) ->
     logger:remove_handler(?MODULE).
 
@@ -326,7 +326,7 @@ formatter_fail(Config) ->
                 filters=>?DEFAULT_HANDLER_FILTERS([?MODULE])},
     %% no formatter!
     logger:add_handler(Name, logger_disk_log_h, HConfig),
-    Pid = whereis(Name),
+    Pid = whereis(h_proc_name(Name)),
     true = is_pid(Pid),
     #{handlers:=HC1} = logger:i(),
     H = [Id || {Id,_,_} <- HC1],
@@ -357,7 +357,7 @@ formatter_fail(Config) ->
                    5000),
 
     %% Check that handler is still alive and was never dead
-    Pid = whereis(Name),
+    Pid = whereis(h_proc_name(Name)),
     #{handlers:=HC2} = logger:i(),
     H = [Id || {Id,_,_} <- HC2],
     ok.
@@ -598,7 +598,7 @@ disk_log_wrap(Config) ->
                        Pid
                end,
     {ok,_} = dbg:tracer(process, {TraceFun, Tester}),
-    {ok,_} = dbg:p(whereis(?MODULE), [c]),
+    {ok,_} = dbg:p(whereis(h_proc_name()), [c]),
     {ok,_} = dbg:tp(logger_disk_log_h, handle_info, 2, []),
 
     Text = [34 + rand:uniform(126-34) || _ <- lists:seq(1,MaxBytes)],
@@ -652,7 +652,7 @@ disk_log_full(Config) ->
                        Pid
                end,
     {ok,_} = dbg:tracer(process, {TraceFun, Tester}),
-    {ok,_} = dbg:p(whereis(?MODULE), [c]),
+    {ok,_} = dbg:p(whereis(h_proc_name()), [c]),
     {ok,_} = dbg:tp(logger_disk_log_h, handle_info, 2, []),
 
     NoOfChars = 5,
@@ -701,10 +701,10 @@ disk_log_events(Config) ->
                        Pid
                end,
     {ok,_} = dbg:tracer(process, {TraceFun, Tester}),
-    {ok,_} = dbg:p(whereis(?MODULE), [c]),
+    {ok,_} = dbg:p(whereis(h_proc_name()), [c]),
     {ok,_} = dbg:tp(logger_disk_log_h, handle_info, 2, []),
     
-    [whereis(?MODULE) ! E || E <- Events],
+    [whereis(h_proc_name()) ! E || E <- Events],
     %% wait for trace messages
     timer:sleep(2000),
     dbg:stop_clear(),
@@ -889,7 +889,7 @@ op_switch_to_drop(Config) ->
                 [send_burst({n,NumOfReqs}, {spawn,Procs,0}, {chars,79}, info) ||
                     _ <- lists:seq(1, Bursts)],
                 Logged = count_lines(Log),
-                ok= stop_handler(?MODULE),
+                ok = stop_handler(?MODULE),
                 _ = file:delete(Log),
                 ct:pal("Number of messages dropped = ~w (~w)",
                        [Procs*NumOfReqs*Bursts-Logged,Procs*NumOfReqs*Bursts]),
@@ -1033,14 +1033,14 @@ kill_disabled(Config) ->
     Logged = count_lines(Log),
     ct:pal("Number of messages logged = ~w", [Logged]),
     ok = file:delete(Log),
-    true = is_pid(whereis(?MODULE)),
+    true = is_pid(whereis(h_proc_name())),
     ok.
 kill_disabled(cleanup, _Config) ->
     ok = stop_handler(?MODULE).
 
 qlen_kill_new(Config) ->
     {_Log,HConfig,DLHConfig} = start_handler(?MODULE, ?FUNCTION_NAME, Config),
-    Pid0 = whereis(?MODULE),
+    Pid0 = whereis(h_proc_name()),
     {_,Mem0} = process_info(Pid0, memory),
     RestartAfter = ?HANDLER_RESTART_AFTER,
     NewHConfig =
@@ -1064,7 +1064,7 @@ qlen_kill_new(Config) ->
                     ct:pal("Slow shutdown, handler process was killed!", [])
             end,
             timer:sleep(RestartAfter + 2000),
-            true = is_pid(whereis(?MODULE)),
+            true = is_pid(whereis(h_proc_name())),
             ok
     after
         5000 ->
@@ -1077,7 +1077,7 @@ qlen_kill_new(cleanup, _Config) ->
 
 mem_kill_new(Config) ->
     {_Log,HConfig,DLHConfig} = start_handler(?MODULE, ?FUNCTION_NAME, Config),
-    Pid0 = whereis(?MODULE),
+    Pid0 = whereis(h_proc_name()),
     {_,Mem0} = process_info(Pid0, memory),
     RestartAfter = ?HANDLER_RESTART_AFTER,
     NewHConfig =
@@ -1101,7 +1101,7 @@ mem_kill_new(Config) ->
                     ct:pal("Slow shutdown, handler process was killed!", [])
             end,
             timer:sleep(RestartAfter + 2000),
-            true = is_pid(whereis(?MODULE)),
+            true = is_pid(whereis(h_proc_name())),
             ok
     after
         5000 ->
@@ -1119,13 +1119,13 @@ restart_after(Config) ->
                                                handler_overloaded_qlen=>10,
                                                handler_restart_after=>never}},
     ok = logger:set_handler_config(?MODULE, NewHConfig1),
-    MRef1 = erlang:monitor(process, whereis(?MODULE)),
+    MRef1 = erlang:monitor(process, whereis(h_proc_name())),
     %% kill handler
     send_burst({n,100}, {spawn,2,0}, {chars,79}, info),
     receive
         {'DOWN', MRef1, _, _, _Info1} ->
             timer:sleep(?HANDLER_RESTART_AFTER + 1000),
-            undefined = whereis(?MODULE),
+            undefined = whereis(h_proc_name()),
             ok
     after
         5000 ->
@@ -1139,14 +1139,14 @@ restart_after(Config) ->
                                                handler_overloaded_qlen=>10,
                                                handler_restart_after=>RestartAfter}},
     ok = logger:set_handler_config(?MODULE, NewHConfig2),
-    Pid0 = whereis(?MODULE),
+    Pid0 = whereis(h_proc_name()),
     MRef2 = erlang:monitor(process, Pid0),
     %% kill handler
     send_burst({n,100}, {spawn,2,0}, {chars,79}, info),
     receive
         {'DOWN', MRef2, _, _, _Info2} ->
             timer:sleep(RestartAfter + 2000),
-            Pid1 = whereis(?MODULE),
+            Pid1 = whereis(h_proc_name()),
             true = is_pid(Pid1),
             false = (Pid1 == Pid0),
             ok
@@ -1225,14 +1225,15 @@ start_handler(Name, FuncName, Config) ->
                                                max_no_bytes => 100000000},
                               filter_default=>log,
                               filters=>?DEFAULT_HANDLER_FILTERS([Name]),
-                              formatter=>{?MODULE,op}}),
+                              formatter=>{?MODULE,op},
+                              level => info}),
     {ok,{_,HConfig = #{logger_disk_log_h := DLHConfig}}} =
         logger:get_handler_config(Name),
     {lists:concat([File,".1"]),HConfig,DLHConfig}.
     
 stop_handler(Name) ->
-    ok = logger:remove_handler(Name),
-    ct:pal("Handler ~p stopped!", [Name]).    
+    ct:pal("Stopping handler ~p!", [Name]),
+    logger:remove_handler(Name).
 
 send_burst(NorT, Type, {chars,Sz}, Class) ->
     Text = [34 + rand:uniform(126-34) || _ <- lists:seq(1,Sz)],
@@ -1331,7 +1332,7 @@ start_and_add(Name, Config, LogOpts) ->
            [Name,Config#{disk_log_opts=>LogOpts}]),
     ok = logger:add_handler(Name, logger_disk_log_h,
                             Config#{disk_log_opts=>LogOpts}),
-    Pid = whereis(Name),
+    Pid = whereis(h_proc_name(Name)),
     true = is_pid(Pid),
     Name = proplists:get_value(name, disk_log:info(Name)),
     ok.
@@ -1339,7 +1340,7 @@ start_and_add(Name, Config, LogOpts) ->
 remove_and_stop(Handler) ->
     ok = logger:remove_handler(Handler),
     timer:sleep(500),
-    undefined = whereis(Handler),
+    undefined = whereis(h_proc_name(Handler)),
     ok.
 
 try_read_file(FileName, Expected, Time) ->
@@ -1442,7 +1443,7 @@ repeat_until_ok(Fun, C, Stop, FirstReason) ->
 start_tracer(Trace,Expected) ->
     Pid = self(),
     dbg:tracer(process,{fun tracer/2,{Pid,Expected}}),
-    dbg:p(whereis(?MODULE),[c]),
+    dbg:p(h_proc_name(),[c]),
     tpl(Trace),
     ok.
 
@@ -1498,3 +1499,8 @@ escape([H|T]) ->
     [H|escape(T)];
 escape([]) ->
     [].
+
+h_proc_name() ->
+    h_proc_name(?MODULE).
+h_proc_name(Name) ->
+    list_to_atom(lists:concat([logger_disk_log_h,"_",Name])).
diff --git a/lib/kernel/test/logger_std_h_SUITE.erl b/lib/kernel/test/logger_std_h_SUITE.erl
index c6391e55fc..fa90be0fc8 100644
--- a/lib/kernel/test/logger_std_h_SUITE.erl
+++ b/lib/kernel/test/logger_std_h_SUITE.erl
@@ -170,7 +170,7 @@ add_remove_instance_file(Log, Type) ->
                               filter_default=>stop,
                               filters=>?DEFAULT_HANDLER_FILTERS([?MODULE]),
                               formatter=>{?MODULE,self()}}),
-    Pid = whereis(?MODULE),
+    Pid = whereis(h_proc_name()),
     true = is_pid(Pid),
     logger:info(M1=?msg,?domain),
     ?check(M1),
@@ -178,7 +178,7 @@ add_remove_instance_file(Log, Type) ->
     try_read_file(Log, {ok,B1}, ?FILESYNC_REP_INT),
     ok = logger:remove_handler(?MODULE),
     timer:sleep(500),
-    undefined = whereis(?MODULE),
+    undefined = whereis(h_proc_name()),
     logger:info(?msg,?domain),
     ?check_no_log,
     try_read_file(Log, {ok,B1}, ?FILESYNC_REP_INT),
@@ -240,7 +240,7 @@ formatter_fail(Config) ->
                             #{logger_std_h => #{type => {file,Log}},
                               filter_default=>stop,
                               filters=>?DEFAULT_HANDLER_FILTERS([?MODULE])}),
-    Pid = whereis(?MODULE),
+    Pid = whereis(h_proc_name()),
     true = is_pid(Pid),
     #{handlers:=HC1} = logger:i(),
     H = [Id || {Id,_,_} <- HC1],
@@ -271,7 +271,7 @@ formatter_fail(Config) ->
                    5000),
 
     %% Check that handler is still alive and was never dead
-    Pid = whereis(?MODULE),
+    Pid = whereis(h_proc_name()),
     #{handlers:=HC2} = logger:i(),
     H = [Id || {Id,_,_} <- HC2],
 
@@ -354,7 +354,12 @@ crash_std_h(Config,Func,Var,Type,Log) ->
     ct:pal("Starting ~p with ~tp", [Name,Args]),
     %% Start a node which prints kernel logs to the destination specified by Type
     {ok,Node} = test_server:start_node(Name, peer, [{args, Args}]),
-    Pid = rpc:call(Node,erlang,whereis,[?STANDARD_HANDLER]),
+    HProcName =
+        case Type of
+            file -> ?name_to_reg_name(logger_std_h,?STANDARD_HANDLER);
+            disk_log -> ?name_to_reg_name(logger_disk_log_h,?STANDARD_HANDLER)
+        end,
+    Pid = rpc:call(Node,erlang,whereis,[HProcName]),
     ok = rpc:call(Node,logger,set_handler_config,[?STANDARD_HANDLER,formatter,
                                                   {?MODULE,self()}]),
     ok = log_on_remote_node(Node,"dummy1"),
@@ -367,7 +372,7 @@ crash_std_h(Config,Func,Var,Type,Log) ->
 
     %% Wait a bit, then check that it is gone
     timer:sleep(2000),
-    undefined = rpc:call(Node,erlang,whereis,[?STANDARD_HANDLER]),
+    undefined = rpc:call(Node,erlang,whereis,[HProcName]),
 
     %% Check that file is not empty
     {ok,Bin2} = sync_and_read(Node,Type,Log),
@@ -940,14 +945,14 @@ kill_disabled(Config) ->
     Logged = count_lines(Log),
     ct:pal("Number of messages logged = ~w", [Logged]),
     ok = file:delete(Log),
-    true = is_pid(whereis(?MODULE)),
+    true = is_pid(whereis(h_proc_name())),
     ok.
 kill_disabled(cleanup, _Config) ->
     ok = stop_handler(?MODULE).
 
 qlen_kill_new(Config) ->
     {_Log,HConfig,StdHConfig} = start_handler(?MODULE, ?FUNCTION_NAME, Config),
-    Pid0 = whereis(?MODULE),
+    Pid0 = whereis(h_proc_name()),
     {_,Mem0} = process_info(Pid0, memory),
     RestartAfter = ?HANDLER_RESTART_AFTER,
      NewHConfig =
@@ -970,7 +975,7 @@ qlen_kill_new(Config) ->
                     ct:pal("Slow shutdown, handler process was killed!", [])
             end,
             timer:sleep(RestartAfter + 2000),
-            true = is_pid(whereis(?MODULE)),
+            true = is_pid(whereis(h_proc_name())),
             ok
     after
         5000 ->
@@ -998,7 +1003,7 @@ qlen_kill_std(_Config) ->
 
 mem_kill_new(Config) ->
     {_Log,HConfig,StdHConfig} = start_handler(?MODULE, ?FUNCTION_NAME, Config),
-    Pid0 = whereis(?MODULE),
+    Pid0 = whereis(h_proc_name()),
     {_,Mem0} = process_info(Pid0, memory),
     RestartAfter = ?HANDLER_RESTART_AFTER,
      NewHConfig =
@@ -1021,7 +1026,7 @@ mem_kill_new(Config) ->
                     ct:pal("Slow shutdown, handler process was killed!", [])
             end,
             timer:sleep(RestartAfter * 3),
-            true = is_pid(whereis(?MODULE)),
+            true = is_pid(whereis(h_proc_name())),
             ok
     after
         5000 ->
@@ -1044,13 +1049,13 @@ restart_after(Config) ->
                                            handler_overloaded_qlen=>10,
                                            handler_restart_after=>never}},
     ok = logger:set_handler_config(?MODULE, NewHConfig1),
-    MRef1 = erlang:monitor(process, whereis(?MODULE)),
+    MRef1 = erlang:monitor(process, whereis(h_proc_name())),
     %% kill handler
     send_burst({n,100}, {spawn,2,0}, {chars,79}, info),
     receive
         {'DOWN', MRef1, _, _, _Info1} ->
             timer:sleep(?HANDLER_RESTART_AFTER + 1000),
-            undefined = whereis(?MODULE),
+            undefined = whereis(h_proc_name()),
             ok
     after
         5000 ->
@@ -1064,14 +1069,14 @@ restart_after(Config) ->
                                            handler_overloaded_qlen=>10,
                                            handler_restart_after=>RestartAfter}},
     ok = logger:set_handler_config(?MODULE, NewHConfig2),
-    Pid0 = whereis(?MODULE),
+    Pid0 = whereis(h_proc_name()),
     MRef2 = erlang:monitor(process, Pid0),
     %% kill handler
     send_burst({n,100}, {spawn,2,0}, {chars,79}, info),
     receive
         {'DOWN', MRef2, _, _, _Info2} ->
             timer:sleep(RestartAfter + 2000),
-            Pid1 = whereis(?MODULE),
+            Pid1 = whereis(h_proc_name()),
             true = is_pid(Pid1),
             false = (Pid1 == Pid0),
             ok
@@ -1286,7 +1291,7 @@ add_remove_instance_nofile(Type) ->
                               filter_default=>stop,
                               filters=>?DEFAULT_HANDLER_FILTERS([?MODULE]),
                               formatter=>{?MODULE,self()}}),
-    Pid = whereis(?MODULE),
+    Pid = whereis(h_proc_name()),
     true = is_pid(Pid),
     group_leader(group_leader(),Pid), % to get printouts in test log
     logger:info(M1=?msg,?domain),
@@ -1295,7 +1300,7 @@ add_remove_instance_nofile(Type) ->
     ok = logger_std_h:sync(?MODULE),
     ok = logger:remove_handler(?MODULE),
     timer:sleep(500),
-    undefined = whereis(?MODULE),
+    undefined = whereis(h_proc_name()),
     logger:info(?msg,?domain),
     ?check_no_log,
     ok.
@@ -1379,7 +1384,7 @@ start_op_trace() ->
     TRecvPid = spawn_link(fun() -> trace_receiver(5000) end),
     {ok,_} = dbg:tracer(process, {TraceFun, TRecvPid}),
 
-    {ok,_} = dbg:p(whereis(?MODULE), [c]),
+    {ok,_} = dbg:p(whereis(h_proc_name()), [c]),
     {ok,_} = dbg:p(self(), [c]),
 
     MS1 = dbg:fun2ms(fun([_]) -> return_trace() end),
@@ -1459,7 +1464,7 @@ start_tracer(Trace,Expected) ->
     Pid = self(),
     FileCtrlPid = maps:get(file_ctrl_pid, logger_std_h:info(?MODULE)),
     dbg:tracer(process,{fun tracer/2,{Pid,Expected}}),
-    dbg:p(whereis(?MODULE),[c]),
+    dbg:p(whereis(h_proc_name()),[c]),
     dbg:p(FileCtrlPid,[c]),
     tpl(Trace),
     ok.
@@ -1525,3 +1530,8 @@ escape([H|T]) ->
     [H|escape(T)];
 escape([]) ->
     [].
+
+h_proc_name() ->
+    h_proc_name(?MODULE).
+h_proc_name(Name) ->
+    ?name_to_reg_name(logger_std_h,Name).