blob: 321afc74823e5d166ec7792053e3e030a6be6bff [file] [log] [blame]
%% Copyright (c) 2011-2012 Basho Technologies, Inc. All Rights Reserved.
%% This file is provided to you 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
%% Unless required by applicable law or agreed to in writing,
%% software distributed under the License is distributed on an
%% KIND, either express or implied. See the License for the
%% specific language governing permissions and limitations
%% under the License.
%% @doc A error_logger backend for redirecting events into lager.
%% Error messages and crash logs are also optionally written to a crash log.
%% @see lager_crash_log
%% @private
-export([init/1, handle_call/2, handle_event/2, handle_info/2, terminate/2,
-record(state, {
%% how many messages per second we try to deliver
hwm = undefined :: 'undefined' | pos_integer(),
%% how many messages we've received this second
mps = 0 :: non_neg_integer(),
%% the current second
lasttime = os:timestamp() :: erlang:timestamp(),
%% count of dropped messages this second
dropped = 0 :: non_neg_integer()
-define(LOGMSG(Level, Pid, Msg),
case ?SHOULD_LOG(Level) of
true ->
_ =lager:log(Level, Pid, Msg),
_ -> ok
-define(LOGFMT(Level, Pid, Fmt, Args),
case ?SHOULD_LOG(Level) of
true ->
_ = lager:log(Level, Pid, Fmt, Args),
_ -> ok
%% Make CRASH synchronous when testing, to avoid timing headaches
catch(gen_server:call(lager_crash_log, {log, Event}))).
gen_server:cast(lager_crash_log, {log, Event})).
set_high_water(N) ->
gen_event:call(error_logger, ?MODULE, {set_high_water, N}, infinity).
-spec init(any()) -> {ok, #state{}}.
init([HighWaterMark]) ->
{ok, #state{hwm=HighWaterMark}}.
handle_call({set_high_water, N}, State) ->
{ok, ok, State#state{hwm = N}};
handle_call(_Request, State) ->
{ok, unknown_call, State}.
handle_event(Event, State) ->
case check_hwm(State) of
{true, NewState} ->
log_event(Event, NewState);
{false, NewState} ->
{ok, NewState}
handle_info(_Info, State) ->
{ok, State}.
terminate(_Reason, _State) ->
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%% internal functions
check_hwm(State = #state{hwm = undefined}) ->
{true, State};
check_hwm(State = #state{mps = Mps, hwm = Hwm}) when Mps < Hwm ->
%% haven't hit high water mark yet, just log it
{true, State#state{mps=Mps+1}};
check_hwm(State = #state{hwm = Hwm, lasttime = Last, dropped = Drop}) ->
%% are we still in the same second?
{M, S, _} = Now = os:timestamp(),
case Last of
{M, S, _} ->
%% still in same second, but have exceeded the high water mark
NewDrops = discard_messages(Now, 0),
{false, State#state{dropped=Drop+NewDrops}};
_ ->
%% different second, reset all counters and allow it
case Drop > 0 of
true ->
?LOGFMT(warning, self(), "lager_error_logger_h dropped ~p messages in the last second that exceeded the limit of ~p messages/sec",
[Drop, Hwm]);
false ->
{true, State#state{dropped = 0, mps=1, lasttime = Now}}
discard_messages(Second, Count) ->
{M, S, _} = os:timestamp(),
case Second of
{M, S, _} ->
%% we only discard gen_event notifications, because
%% otherwise we might discard gen_event internal
%% messages, such as trapped EXITs
{notify, _Event} ->
discard_messages(Second, Count+1);
{_From, _Tag, {sync_notify, _Event}} ->
discard_messages(Second, Count+1)
after 0 ->
_ ->
log_event(Event, State) ->
case Event of
{error, _GL, {Pid, Fmt, Args}} ->
case Fmt of
"** Generic server "++_ ->
%% gen_server terminate
[Name, _Msg, _State, Reason] = Args,
?LOGFMT(error, Pid, "gen_server ~w terminated with reason: ~s",
[Name, format_reason(Reason)]);
"** State machine "++_ ->
%% gen_fsm terminate
[Name, _Msg, StateName, _StateData, Reason] = Args,
?LOGFMT(error, Pid, "gen_fsm ~w in state ~w terminated with reason: ~s",
[Name, StateName, format_reason(Reason)]);
"** gen_event handler"++_ ->
%% gen_event handler terminate
[ID, Name, _Msg, _State, Reason] = Args,
?LOGFMT(error, Pid, "gen_event ~w installed in ~w terminated with reason: ~s",
[ID, Name, format_reason(Reason)]);
"** Cowboy handler"++_ ->
%% Cowboy HTTP server error
case Args of
[Module, Function, Arity, _Request, _State] ->
%% we only get the 5-element list when its a non-exported function
?LOGFMT(error, Pid,
"Cowboy handler ~p terminated with reason: call to undefined function ~p:~p/~p",
[Module, Module, Function, Arity]);
[Module, Function, Arity, _Class, Reason | Tail] ->
%% any other cowboy error_format list *always* ends with the stacktrace
StackTrace = lists:last(Tail),
?LOGFMT(error, Pid,
"Cowboy handler ~p terminated in ~p:~p/~p with reason: ~s",
[Module, Module, Function, Arity, format_reason({Reason, StackTrace})])
"webmachine error"++_ ->
%% Webmachine HTTP server error
[Path, Error] = Args,
%% webmachine likes to mangle the stack, for some reason
StackTrace = case Error of
{error, {error, Reason, Stack}} ->
{Reason, Stack};
_ ->
?LOGFMT(error, Pid, "Webmachine error at path ~p : ~s", [Path, format_reason(StackTrace)]);
_ ->
?LOGMSG(error, Pid, lager:safe_format(Fmt, Args, ?DEFAULT_TRUNCATION))
{error_report, _GL, {Pid, std_error, D}} ->
?LOGMSG(error, Pid, print_silly_list(D));
{error_report, _GL, {Pid, supervisor_report, D}} ->
case lists:sort(D) of
[{errorContext, Ctx}, {offender, Off}, {reason, Reason}, {supervisor, Name}] ->
Offender = format_offender(Off),
?LOGFMT(error, Pid,
"Supervisor ~w had child ~s exit with reason ~s in context ~w",
[supervisor_name(Name), Offender, format_reason(Reason), Ctx]);
_ ->
?LOGMSG(error, Pid, "SUPERVISOR REPORT " ++ print_silly_list(D))
{error_report, _GL, {Pid, crash_report, [Self, Neighbours]}} ->
?LOGMSG(error, Pid, "CRASH REPORT " ++ format_crash_report(Self, Neighbours));
{warning_msg, _GL, {Pid, Fmt, Args}} ->
?LOGMSG(warning, Pid, lager:safe_format(Fmt, Args, ?DEFAULT_TRUNCATION));
{warning_report, _GL, {Pid, std_warning, Report}} ->
?LOGMSG(warning, Pid, print_silly_list(Report));
{info_msg, _GL, {Pid, Fmt, Args}} ->
?LOGMSG(info, Pid, lager:safe_format(Fmt, Args, ?DEFAULT_TRUNCATION));
{info_report, _GL, {Pid, std_info, D}} when is_list(D) ->
Details = lists:sort(D),
case Details of
[{application, App}, {exited, Reason}, {type, _Type}] ->
?LOGFMT(info, Pid, "Application ~w exited with reason: ~s",
[App, format_reason(Reason)]);
_ ->
?LOGMSG(info, Pid, print_silly_list(D))
{info_report, _GL, {Pid, std_info, D}} ->
?LOGFMT(info, Pid, "~w", [D]);
{info_report, _GL, {P, progress, D}} ->
Details = lists:sort(D),
case Details of
[{application, App}, {started_at, Node}] ->
?LOGFMT(info, P, "Application ~w started on node ~w",
[App, Node]);
[{started, Started}, {supervisor, Name}] ->
MFA = format_mfa(get_value(mfargs, Started)),
Pid = get_value(pid, Started),
?LOGFMT(debug, P, "Supervisor ~w started ~s at pid ~w",
[supervisor_name(Name), MFA, Pid]);
_ ->
?LOGMSG(info, P, "PROGRESS REPORT " ++ print_silly_list(D))
_ ->
?LOGFMT(warning, self(), "Unexpected error_logger event ~w", [Event])
{ok, State}.
format_crash_report(Report, Neighbours) ->
Name = case get_value(registered_name, Report, []) of
[] ->
%% process_info(Pid, registered_name) returns [] for unregistered processes
get_value(pid, Report);
Atom -> Atom
{Class, Reason, Trace} = get_value(error_info, Report),
ReasonStr = format_reason({Reason, Trace}),
Type = case Class of
exit -> "exited";
_ -> "crashed"
io_lib:format("Process ~w with ~w neighbours ~s with reason: ~s",
[Name, length(Neighbours), Type, ReasonStr]).
format_offender(Off) ->
case get_value(mfargs, Off) of
undefined ->
%% supervisor_bridge
io_lib:format("at module ~w at ~w",
[get_value(mod, Off), get_value(pid, Off)]);
MFArgs ->
%% regular supervisor
MFA = format_mfa(MFArgs),
Name = get_value(name, Off),
io_lib:format("~p started with ~s at ~w",
[Name, MFA, get_value(pid, Off)])
format_reason({'function not exported', [{M, F, A},MFA|_]}) ->
["call to undefined function ", format_mfa({M, F, length(A)}),
" from ", format_mfa(MFA)];
format_reason({'function not exported', [{M, F, A, _Props},MFA|_]}) ->
%% R15 line numbers
["call to undefined function ", format_mfa({M, F, length(A)}),
" from ", format_mfa(MFA)];
format_reason({undef, [MFA|_]}) ->
["call to undefined function ", format_mfa(MFA)];
format_reason({bad_return, {_MFA, {'EXIT', Reason}}}) ->
format_reason({bad_return, {MFA, Val}}) ->
["bad return value ", print_val(Val), " from ", format_mfa(MFA)];
format_reason({bad_return_value, Val}) ->
["bad return value: ", print_val(Val)];
format_reason({{bad_return_value, Val}, MFA}) ->
["bad return value: ", print_val(Val), " in ", format_mfa(MFA)];
format_reason({{badrecord, Record}, [MFA|_]}) ->
["bad record ", print_val(Record), " in ", format_mfa(MFA)];
format_reason({{case_clause, Val}, [MFA|_]}) ->
["no case clause matching ", print_val(Val), " in ", format_mfa(MFA)];
format_reason({function_clause, [MFA|_]}) ->
["no function clause matching ", format_mfa(MFA)];
format_reason({if_clause, [MFA|_]}) ->
["no true branch found while evaluating if expression in ", format_mfa(MFA)];
format_reason({{try_clause, Val}, [MFA|_]}) ->
["no try clause matching ", print_val(Val), " in ", format_mfa(MFA)];
format_reason({badarith, [MFA|_]}) ->
["bad arithmetic expression in ", format_mfa(MFA)];
format_reason({{badmatch, Val}, [MFA|_]}) ->
["no match of right hand value ", print_val(Val), " in ", format_mfa(MFA)];
format_reason({emfile, _Trace}) ->
"maximum number of file descriptors exhausted, check ulimit -n";
format_reason({system_limit, [{M, F, _}|_] = Trace}) ->
Limit = case {M, F} of
{erlang, open_port} ->
"maximum number of ports exceeded";
{erlang, spawn} ->
"maximum number of processes exceeded";
{erlang, spawn_opt} ->
"maximum number of processes exceeded";
{erlang, list_to_atom} ->
"tried to create an atom larger than 255, or maximum atom count exceeded";
{ets, new} ->
"maximum number of ETS tables exceeded";
_ ->
{Str, _} = lager_trunc_io:print(Trace, 500),
["system limit: ", Limit];
format_reason({badarg, [MFA,MFA2|_]}) ->
case MFA of
{_M, _F, A, _Props} when is_list(A) ->
%% R15 line numbers
["bad argument in call to ", format_mfa(MFA), " in ", format_mfa(MFA2)];
{_M, _F, A} when is_list(A) ->
["bad argument in call to ", format_mfa(MFA), " in ", format_mfa(MFA2)];
_ ->
%% seems to be generated by a bad call to a BIF
["bad argument in ", format_mfa(MFA)]
format_reason({{badarity, {Fun, Args}}, [MFA|_]}) ->
{arity, Arity} = lists:keyfind(arity, 1, erlang:fun_info(Fun)),
[io_lib:format("fun called with wrong arity of ~w instead of ~w in ",
[length(Args), Arity]), format_mfa(MFA)];
format_reason({noproc, MFA}) ->
["no such process or port in call to ", format_mfa(MFA)];
format_reason({{badfun, Term}, [MFA|_]}) ->
["bad function ", print_val(Term), " in ", format_mfa(MFA)];
format_reason({Reason, [{M, F, A}|_]}) when is_atom(M), is_atom(F), is_integer(A) ->
[format_reason(Reason), " in ", format_mfa({M, F, A})];
format_reason({Reason, [{M, F, A, Props}|_]}) when is_atom(M), is_atom(F), is_integer(A), is_list(Props) ->
%% line numbers
[format_reason(Reason), " in ", format_mfa({M, F, A, Props})];
format_reason(Reason) ->
{Str, _} = lager_trunc_io:print(Reason, 500),
format_mfa({M, F, A}) when is_list(A) ->
{FmtStr, Args} = format_args(A, [], []),
io_lib:format("~w:~w("++FmtStr++")", [M, F | Args]);
format_mfa({M, F, A}) when is_integer(A) ->
io_lib:format("~w:~w/~w", [M, F, A]);
format_mfa({M, F, A, Props}) when is_list(Props) ->
case get_value(line, Props) of
undefined ->
format_mfa({M, F, A});
Line ->
[format_mfa({M, F, A}), io_lib:format(" line ~w", [Line])]
format_mfa([{M, F, A}, _]) ->
%% this kind of weird stacktrace can be generated by a uncaught throw in a gen_server
format_mfa({M, F, A});
format_mfa([{M, F, A, Props}, _]) when is_list(Props) ->
%% this kind of weird stacktrace can be generated by a uncaught throw in a gen_server
format_mfa({M, F, A, Props});
format_mfa(Other) ->
io_lib:format("~w", [Other]).
format_args([], FmtAcc, ArgsAcc) ->
{string:join(lists:reverse(FmtAcc), ", "), lists:reverse(ArgsAcc)};
format_args([H|T], FmtAcc, ArgsAcc) ->
{Str, _} = lager_trunc_io:print(H, 100),
format_args(T, ["~s"|FmtAcc], [Str|ArgsAcc]).
print_silly_list(L) when is_list(L) ->
case lager_stdlib:string_p(L) of
true ->
lager_trunc_io:format("~s", [L], ?DEFAULT_TRUNCATION);
_ ->
print_silly_list(L, [], [])
print_silly_list(L) ->
{Str, _} = lager_trunc_io:print(L, ?DEFAULT_TRUNCATION),
print_silly_list([], Fmt, Acc) ->
lager_trunc_io:format(string:join(lists:reverse(Fmt), ", "),
lists:reverse(Acc), ?DEFAULT_TRUNCATION);
print_silly_list([{K,V}|T], Fmt, Acc) ->
print_silly_list(T, ["~p: ~p" | Fmt], [V, K | Acc]);
print_silly_list([H|T], Fmt, Acc) ->
print_silly_list(T, ["~p" | Fmt], [H | Acc]).
print_val(Val) ->
{Str, _} = lager_trunc_io:print(Val, 500),
%% @doc Faster than proplists, but with the same API as long as you don't need to
%% handle bare atom keys
get_value(Key, Value) ->
get_value(Key, Value, undefined).
get_value(Key, List, Default) ->
case lists:keyfind(Key, 1, List) of
false -> Default;
{Key, Value} -> Value
supervisor_name({local, Name}) -> Name;
supervisor_name(Name) -> Name.