%% %% %CopyrightBegin% %% %% Copyright Ericsson AB 2017. All Rights Reserved. %% %% Licensed under the Apache License, Version 2.0 (the "License"); %% you may not use this file except in compliance with the License. %% You may obtain a copy of the License at %% %% http://www.apache.org/licenses/LICENSE-2.0 %% %% Unless required by applicable law or agreed to in writing, software %% distributed under the License is distributed on an "AS IS" BASIS, %% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %% See the License for the specific language governing permissions and %% limitations under the License. %% %% %CopyrightEnd% %% -module(logger_disk_log_h). -behaviour(gen_server). -include("logger.hrl"). -include("logger_internal.hrl"). -include("logger_h_common.hrl"). %%% API -export([start_link/3, info/1, sync/1, reset/1]). %% gen_server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). %% logger callbacks -export([log/2, adding_handler/1, removing_handler/1, changing_config/2, swap_buffer/2]). %% handler internal -export([log_handler_info/4]). %%%=================================================================== %%% API %%%=================================================================== %%%----------------------------------------------------------------- %%% Start a disk_log handler process and link to caller. %%% This function is called by the kernel supervisor when this %%% handler process gets added (as a result of calling add/3). -spec start_link(Name, Config, HandlerState) -> {ok,Pid} | {error,Reason} when Name :: atom(), Config :: logger:config(), HandlerState :: map(), Pid :: pid(), Reason :: term(). start_link(Name, Config, HandlerState) -> proc_lib:start_link(?MODULE,init,[[Name,Config,HandlerState]]). %%%----------------------------------------------------------------- %%% -spec sync(Name) -> ok | {error,Reason} when Name :: atom(), Reason :: handler_busy | {badarg,term()}. sync(Name) when is_atom(Name) -> try gen_server:call(?name_to_reg_name(?MODULE,Name), disk_log_sync, ?DEFAULT_CALL_TIMEOUT) catch _:{timeout,_} -> {error,handler_busy} end; sync(Name) -> {error,{badarg,{sync,[Name]}}}. %%%----------------------------------------------------------------- %%% -spec info(Name) -> Info | {error,Reason} when Name :: atom(), Info :: term(), Reason :: handler_busy | {badarg,term()}. info(Name) when is_atom(Name) -> try gen_server:call(?name_to_reg_name(?MODULE,Name), info, ?DEFAULT_CALL_TIMEOUT) catch _:{timeout,_} -> {error,handler_busy} end; info(Name) -> {error,{badarg,{info,[Name]}}}. %%%----------------------------------------------------------------- %%% -spec reset(Name) -> ok | {error,Reason} when Name :: atom(), Reason :: handler_busy | {badarg,term()}. reset(Name) when is_atom(Name) -> try gen_server:call(?name_to_reg_name(?MODULE,Name), reset, ?DEFAULT_CALL_TIMEOUT) catch _:{timeout,_} -> {error,handler_busy} end; reset(Name) -> {error,{badarg,{reset,[Name]}}}. %%%=================================================================== %%% logger callbacks %%%=================================================================== %%%----------------------------------------------------------------- %%% Handler being added adding_handler(#{id:=Name}=Config) -> case check_config(adding, Config) of {ok, Config1} -> %% create initial handler state by merging defaults with config HConfig = maps:get(config, Config1, #{}), HState = maps:merge(get_init_state(), HConfig), case logger_h_common:overload_levels_ok(HState) of true -> case start(Name, Config1, HState) of {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,Config2)}; Error -> Error end; false -> #{toggle_sync_qlen := TSQL, drop_new_reqs_qlen := DNRQL, flush_reqs_qlen := FRQL} = HState, {error,{invalid_levels,{TSQL,DNRQL,FRQL}}} end; Error -> Error end. %%%----------------------------------------------------------------- %%% Updating handler config changing_config(OldConfig=#{id:=Name, disk_log_opts:=DLOpts, config:=HConfig}, NewConfig=#{id:=Name, disk_log_opts:=DLOpts}) -> case check_config(changing, NewConfig) of {ok,NewConfig1 = #{config:=NewHConfig}} -> #{handler_pid:=HPid, mode_tab:=ModeTab} = HConfig, NewHConfig1 = NewHConfig#{handler_pid=>HPid, mode_tab=>ModeTab}, NewConfig2 = NewConfig1#{config=>NewHConfig1}, try gen_server:call(HPid, {change_config,OldConfig,NewConfig2}, ?DEFAULT_CALL_TIMEOUT) of ok -> {ok,NewConfig2}; HError -> HError catch _:{timeout,_} -> {error,handler_busy} end; Error -> Error end; changing_config(OldConfig, NewConfig) -> {error,{illegal_config_change,OldConfig,NewConfig}}. check_config(adding, #{id:=Name}=Config) -> %% Merge in defaults on handler level LogOpts0 = maps:get(disk_log_opts, Config, #{}), LogOpts = merge_default_logopts(Name, LogOpts0), case check_log_opts(maps:to_list(LogOpts)) of ok -> MyConfig = maps:get(config, Config, #{}), case check_my_config(maps:to_list(MyConfig)) of ok -> {ok,Config#{disk_log_opts=>LogOpts, config=>MyConfig}}; Error -> Error end; Error -> Error end; check_config(changing, Config) -> MyConfig = maps:get(config, Config, #{}), case check_my_config(maps:to_list(MyConfig)) of ok -> {ok,Config}; Error -> Error end. merge_default_logopts(Name, LogOpts) -> Type = maps:get(type, LogOpts, wrap), {DefaultNoFiles,DefaultNoBytes} = case Type of halt -> {undefined,infinity}; _wrap -> {10,1048576} end, {ok,Dir} = file:get_cwd(), Default = #{file => filename:join(Dir,Name), max_no_files => DefaultNoFiles, max_no_bytes => DefaultNoBytes, type => Type}, maps:merge(Default,LogOpts). check_log_opts([{file,File}|Opts]) when is_list(File) -> check_log_opts(Opts); check_log_opts([{max_no_files,undefined}|Opts]) -> check_log_opts(Opts); check_log_opts([{max_no_files,N}|Opts]) when is_integer(N), N>0 -> check_log_opts(Opts); check_log_opts([{max_no_bytes,infinity}|Opts]) -> check_log_opts(Opts); check_log_opts([{max_no_bytes,N}|Opts]) when is_integer(N), N>0 -> check_log_opts(Opts); check_log_opts([{type,Type}|Opts]) when Type==wrap; Type==halt -> check_log_opts(Opts); check_log_opts([Invalid|_]) -> {error,{invalid_config,disk_log_opt,Invalid}}; check_log_opts([]) -> ok. check_my_config([Other | Config]) -> case logger_h_common:check_common_config(Other) of valid -> check_my_config(Config); invalid -> {error,{invalid_config,?MODULE,Other}} end; check_my_config([]) -> ok. %%%----------------------------------------------------------------- %%% Handler being removed removing_handler(#{id:=Name}) -> stop(Name). %%%----------------------------------------------------------------- %%% Get buffer when swapping from simple handler swap_buffer(Name, Buffer) -> case whereis(?name_to_reg_name(?MODULE,Name)) of undefined -> ok; Pid -> Pid ! {buffer,Buffer} end. %%%----------------------------------------------------------------- %%% Log a string or report -spec log(LogEvent, Config) -> ok | dropped when LogEvent :: logger:log_event(), Config :: logger:config(). log(LogEvent, Config = #{id := Name, config := #{handler_pid := HPid, mode_tab := ModeTab}}) -> %% if the handler has crashed, we must drop this event %% and hope the handler restarts so we can try again 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 = #{config := HConfig, disk_log_opts := LogOpts}, State = #{dl_sync_int := DLSyncInt}]) -> register(?name_to_reg_name(?MODULE,Name), self()), process_flag(trap_exit, true), process_flag(message_queue_data, off_heap), ?init_test_hooks(), ?start_observation(Name), case open_disk_log(Name, LogOpts) of ok -> 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#{config => HConfig#{handler_pid => self(), mode_tab => ModeTab}}, proc_lib:init_ack({ok,self(),Config1}), gen_server:cast(self(), repeated_disk_log_sync), case logger_h_common:unset_restart_flag(Name, ?MODULE) of true -> %% inform about restart gen_server:cast(self(), {log_handler_info, "Handler ~p restarted", [Name]}); false -> %% initial start ok end, 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) end. enter_loop(#{wait_for_buffer:=true}=Config,State) -> State1 = receive {buffer,Buffer} -> lists:foldl( fun(Log,S) -> Bin = logger_h_common:log_to_binary(Log,Config), {_,S1} = do_log(Bin,cast,S), S1 end, State, Buffer) end, gen_server:enter_loop(?MODULE,[],State1); enter_loop(_Config,State) -> gen_server:enter_loop(?MODULE,[],State). %% This is the synchronous log event. handle_call({log, Bin}, _From, State) -> {Result,State1} = do_log(Bin, call, State), %% Result == ok | dropped {reply, Result, State1}; handle_call(disk_log_sync, _From, State = #{id := Name}) -> State1 = #{prev_sync_result := Result} = disk_log_sync(Name, State), {reply, Result, State1}; handle_call({change_config,_OldConfig,NewConfig}, _From, State = #{filesync_repeat_interval := FSyncInt0}) -> HConfig = maps:get(config, NewConfig, #{}), State1 = #{toggle_sync_qlen := TSQL, drop_new_reqs_qlen := DNRQL, flush_reqs_qlen := FRQL} = maps:merge(State, HConfig), case logger_h_common:overload_levels_ok(State1) of true -> _ = case maps:get(filesync_repeat_interval, HConfig, undefined) of undefined -> ok; no_repeat -> _ = logger_h_common:cancel_timer(maps:get(rep_sync_tref, State, undefined)); FSyncInt0 -> ok; _FSyncInt1 -> _ = logger_h_common:cancel_timer(maps:get(rep_sync_tref, State, undefined)), _ = gen_server:cast(self(), repeated_disk_log_sync) end, {reply, ok, State1}; false -> {reply, {error,{invalid_levels,{TSQL,DNRQL,FRQL}}}, State} end; handle_call(info, _From, State) -> {reply, State, State}; handle_call(reset, _From, State) -> State1 = ?merge_with_stats(State), {reply, ok, State1#{last_qlen => 0, last_log_ts => ?timestamp(), prev_log_result => ok, prev_sync_result => ok, prev_disk_log_info => undefined}}; handle_call(stop, _From, State) -> {stop, {shutdown,stopped}, ok, State}. %% This is the asynchronous log event. handle_cast({log, Bin}, State) -> {_,State1} = do_log(Bin, cast, State), {noreply, State1}; handle_cast({log_handler_info, Format, Args}, State = #{id:=Name}) -> log_handler_info(Name, Format, Args, State), {noreply, State}; %% If FILESYNC_REPEAT_INTERVAL is set to a millisec value, this %% clause gets called repeatedly by the handler. In order to %% guarantee that a filesync *always* happens after the last log %% event, the repeat operation must be active! handle_cast(repeated_disk_log_sync, State = #{id := Name, filesync_repeat_interval := FSyncInt, last_op := LastOp}) -> State1 = if is_integer(FSyncInt) -> %% only do filesync if something has been %% written since last time we checked NewState = if LastOp == sync -> State; true -> disk_log_sync(Name, State) end, {ok,TRef} = timer:apply_after(FSyncInt, gen_server,cast, [self(),repeated_disk_log_sync]), NewState#{rep_sync_tref => TRef, last_op => sync}; true -> State end, {noreply,State1}. %% The disk log owner must handle status messages from disk_log. handle_info({disk_log, _Node, _Log, {wrap,_NoLostItems}}, State) -> {noreply, State}; handle_info({disk_log, _Node, Log, Info = {truncated,_NoLostItems}}, State = #{id := Name, prev_disk_log_info := PrevInfo}) -> error_notify_new(Info, PrevInfo, {disk_log,Name,Log,Info}), {noreply, State#{prev_disk_log_info => Info}}; handle_info({disk_log, _Node, Log, Info = {blocked_log,_Items}}, State = #{id := Name, prev_disk_log_info := PrevInfo}) -> error_notify_new(Info, PrevInfo, {disk_log,Name,Log,Info}), {noreply, State#{prev_disk_log_info => Info}}; handle_info({disk_log, _Node, Log, full}, State = #{id := Name, prev_disk_log_info := PrevInfo}) -> error_notify_new(full, PrevInfo, {disk_log,Name,Log,full}), {noreply, State#{prev_disk_log_info => full}}; handle_info({disk_log, _Node, Log, Info = {error_status,_Status}}, State = #{id := Name, prev_disk_log_info := PrevInfo}) -> error_notify_new(Info, PrevInfo, {disk_log,Name,Log,Info}), {noreply, State#{prev_disk_log_info => Info}}; handle_info({'EXIT',_Pid,_Why}, State = #{id := _Name}) -> {noreply, State}; handle_info(_, State) -> {noreply, State}. terminate(Reason, State = #{id := Name}) -> _ = logger_h_common:cancel_timer(maps:get(rep_sync_tref, State, undefined)), _ = close_disk_log(Name, normal), logger_h_common:stop_or_restart(Name, Reason, State). code_change(_OldVsn, State, _Extra) -> {ok, State}. %%%----------------------------------------------------------------- %%% Internal functions %%%----------------------------------------------------------------- %%% get_init_state() -> #{toggle_sync_qlen => ?TOGGLE_SYNC_QLEN, drop_new_reqs_qlen => ?DROP_NEW_REQS_QLEN, flush_reqs_qlen => ?FLUSH_REQS_QLEN, enable_burst_limit => ?ENABLE_BURST_LIMIT, burst_limit_size => ?BURST_LIMIT_SIZE, burst_window_time => ?BURST_WINDOW_TIME, enable_kill_overloaded => ?ENABLE_KILL_OVERLOADED, handler_overloaded_qlen => ?HANDLER_OVERLOADED_QLEN, handler_overloaded_mem => ?HANDLER_OVERLOADED_MEM, handler_restart_after => ?HANDLER_RESTART_AFTER, dl_sync_int => ?CONTROLLER_SYNC_INTERVAL, filesync_ok_qlen => ?FILESYNC_OK_QLEN, filesync_repeat_interval => ?FILESYNC_REPEAT_INTERVAL}. %%%----------------------------------------------------------------- %%% Add a disk_log handler to the logger. %%% This starts a dedicated handler process which should always %%% exist if the handler is registered with logger (and should not %%% exist if the handler is not registered). %%% %%% Config is the logger:config() map containing a sub map with any of %%% the following associations: %%% %%% Config = #{disk_log_opts => #{file => file:filename(), %%% max_no_bytes => integer(), %%% max_no_files => integer(), %%% type => wrap | halt}}. %%% %%% This map will be merged with the logger configuration data for %%% the disk_log LogName. If type == halt, then max_no_files is %%% ignored. %%% %%% Handler specific config should be provided with a sub map associated %%% with a key named 'config', e.g: %%% %%% Config = #{config => #{toggle_sync_qlen => 50} %%% %%% The disk_log handler process is linked to logger_sup, which is %%% part of the kernel application's supervision tree. start(Name, Config, HandlerState) -> LoggerDLH = #{id => Name, start => {?MODULE, start_link, [Name,Config,HandlerState]}, restart => temporary, shutdown => 2000, type => worker, modules => [?MODULE]}, case supervisor:start_child(logger_sup, LoggerDLH) of {ok,_Pid,Config1} -> {ok,Config1}; Error -> Error end. %%%----------------------------------------------------------------- %%% Stop and remove the handler. stop(Name) -> 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(Pid, stop), _ = supervisor:delete_child(logger_sup, Name), ok end. %%%----------------------------------------------------------------- %%% Logging and overload control. -define(update_dl_sync(C, Interval), if C == 0 -> Interval; true -> C-1 end). %% check for overload between every event (and set Mode to async, %% sync or drop accordingly), but never flush the whole mailbox %% before LogWindowSize events have been handled do_log(Bin, CallOrCast, State = #{id:=Name, mode := Mode0}) -> T1 = ?timestamp(), %% check if the handler is getting overloaded, or if it's %% recovering from overload (the check must be done for each %% event to react quickly to large bursts of events and %% to ensure that the handler can never end up in drop mode %% with an empty mailbox, which would stop operation) {Mode1,QLen,Mem,State1} = logger_h_common:check_load(State), if (Mode1 == drop) andalso (Mode0 =/= drop) -> log_handler_info(Name, "Handler ~p switched to drop mode", [Name], State); (Mode0 == drop) andalso ((Mode1 == async) orelse (Mode1 == sync)) -> log_handler_info(Name, "Handler ~p switched to ~w mode", [Name,Mode1], State); true -> ok end, %% kill the handler if it can't keep up with the load logger_h_common:kill_if_choked(Name, QLen, Mem, ?MODULE, State), if Mode1 == flush -> flush(Name, QLen, T1, State1); true -> write(Name, Mode1, T1, Bin, CallOrCast, State1) end. %% 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, mode_tab := ModeTab}) -> %% flush messages in the mailbox (a limited number in %% order to not cause long delays) NewFlushed = logger_h_common:flush_log_events(?FLUSH_MAX_N), %% write info in log about flushed messages log_handler_info(Name, "Handler ~p flushed ~w log events", [Name,NewFlushed], State), %% because of the receive loop when flushing messages, the %% 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}), %% Add 1 for the current log event ?observe(Name,{flushed,NewFlushed+1}), State1 = ?update_max_time(?diff_time(T1,_T0),State), {dropped,?update_other(flushed,FLUSHED,NewFlushed, 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 = #{mode_tab := ModeTab, dl_sync := DLSync, dl_sync_int := DLSyncInt, last_qlen := LastQLen, last_log_ts := T0}) -> %% check if we need to limit the number of writes %% during a burst of log events {DoWrite,BurstWinT,BurstMsgCount} = logger_h_common:limit_burst(State), %% only send a synhrounous event to the disk_log process %% every DLSyncInt time, to give the handler time between %% writes so it can keep up with incoming messages {Status,LastQLen1,State1} = if DoWrite, DLSync == 0 -> ?observe(Name,{_CallOrCast,1}), NewState = disk_log_write(Name, Bin, State), {ok, element(2,process_info(self(),message_queue_len)), NewState}; DoWrite -> ?observe(Name,{_CallOrCast,1}), NewState = disk_log_write(Name, Bin, State), {ok, LastQLen, NewState}; not DoWrite -> ?observe(Name,{flushed,1}), {dropped, LastQLen, State} end, %% Check if the time since the previous log event is long enough - %% and the queue length small enough - to assume the mailbox has %% been emptied, and if so, do filesync operation and reset mode to %% async. Note that this is the best we can do to detect an idle %% handler without setting a timer after each log call/cast. If the %% time between two consecutive log events is fast and no new %% event comes in after the last one, idle state won't be detected! Time = ?diff_time(T1,T0), {Mode1,BurstMsgCount1,State2} = if (LastQLen1 < ?FILESYNC_OK_QLEN) andalso (Time > ?IDLE_DETECT_TIME_USEC) -> {?change_mode(ModeTab,Mode,async), 0, disk_log_sync(Name,State1)}; true -> {Mode, BurstMsgCount,State1} end, State3 = ?update_calls_or_casts(_CallOrCast,1,State2), State4 = ?update_max_time(Time, State3#{mode => Mode1, last_qlen := LastQLen1, last_log_ts => T1, burst_win_ts => BurstWinT, burst_msg_count => BurstMsgCount1, dl_sync => ?update_dl_sync(DLSync,DLSyncInt)}), {Status,State4}. log_handler_info(Name, Format, Args, State) -> Config = case logger:get_handler_config(Name) of {ok,Conf} -> Conf; _ -> #{formatter=>{?DEFAULT_FORMATTER,?DEFAULT_FORMAT_CONFIG}} end, Meta = #{time=>erlang:system_time(microsecond)}, Bin = logger_h_common:log_to_binary(#{level => notice, msg => {Format,Args}, meta => Meta}, Config), _ = disk_log_write(Name, Bin, State), ok. open_disk_log(Name, LogOpts) -> #{file := File, max_no_bytes := MaxNoBytes, max_no_files := MaxNoFiles, type := Type} = LogOpts, case filelib:ensure_dir(File) of ok -> Size = if Type == halt -> MaxNoBytes; Type == wrap -> {MaxNoBytes,MaxNoFiles} end, Opts = [{name, Name}, {file, File}, {size, Size}, {type, Type}, {linkto, self()}, {repair, false}, {format, external}, {notify, true}, {quiet, true}, {mode, read_write}], case disk_log:open(Opts) of {ok,Name} -> ok; Error = {error,_Reason} -> Error end; Error -> Error end. close_disk_log(Name, _) -> _ = ?disk_log_sync(Name), _ = disk_log:lclose(Name), ok. disk_log_write(Name, Bin, State) -> case ?disk_log_blog(Name, Bin) of ok -> State#{prev_log_result => ok, last_op => write}; LogError -> _ = case maps:get(prev_log_result, State) of LogError -> %% don't report same error twice ok; _ -> LogOpts = maps:get(log_opts, State), logger_h_common:error_notify({Name,log, LogOpts, LogError}) end, State#{prev_log_result => LogError} end. disk_log_sync(Name, State) -> case ?disk_log_sync(Name) of ok -> State#{prev_sync_result => ok, last_op => sync}; SyncError -> _ = case maps:get(prev_sync_result, State) of SyncError -> %% don't report same error twice ok; _ -> LogOpts = maps:get(log_opts, State), logger_h_common:error_notify({Name,sync, LogOpts, SyncError}) end, State#{prev_sync_result => SyncError} end. error_notify_new(Info,Info, _Term) -> ok; error_notify_new(_Info0,_Info1, Term) -> logger_h_common:error_notify(Term).