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Diffstat (limited to 'lib/kernel/src/logger_olp.hrl')
| -rw-r--r-- | lib/kernel/src/logger_olp.hrl | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/lib/kernel/src/logger_olp.hrl b/lib/kernel/src/logger_olp.hrl new file mode 100644 index 0000000000..9b4f5ebf27 --- /dev/null +++ b/lib/kernel/src/logger_olp.hrl @@ -0,0 +1,180 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 1997-2015. 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% +%% + +%%%----------------------------------------------------------------- +%%% Overload protection configuration + +%%! *** NOTE *** +%%! It's important that: +%%! SYNC_MODE_QLEN =< DROP_MODE_QLEN =< FLUSH_QLEN +%%! and that DROP_MODE_QLEN >= 2. +%%! Otherwise the process could end up in drop mode with no new +%%! log requests to process. This would cause all future requests +%%! to be dropped (no switch to async mode would ever take place). + +%% This specifies the message_queue_len value where the log +%% requests switch from asynchronous casts to synchronous calls. +-define(SYNC_MODE_QLEN, 10). +%% Above this message_queue_len, log requests will be dropped, +%% i.e. no log requests get sent to the process. +-define(DROP_MODE_QLEN, 200). +%% Above this message_queue_len, the process will flush its mailbox +%% and only leave this number of messages in it. +-define(FLUSH_QLEN, 1000). + +%% Never flush more than this number of messages in one go, or the +%% process will be unresponsive for seconds (keep this number as large +%% as possible or the mailbox could grow large). +-define(FLUSH_MAX_N, 5000). + +%% BURST_LIMIT_MAX_COUNT is the max number of log requests allowed +%% to be written within a BURST_LIMIT_WINDOW_TIME time frame. +-define(BURST_LIMIT_ENABLE, true). +-define(BURST_LIMIT_MAX_COUNT, 500). +-define(BURST_LIMIT_WINDOW_TIME, 1000). + +%% This enables/disables the feature to automatically terminate the +%% process if it gets too loaded (and can't keep up). +-define(OVERLOAD_KILL_ENABLE, false). +%% If the message_queue_len goes above this size even after +%% flushing has been performed, the process is terminated. +-define(OVERLOAD_KILL_QLEN, 20000). +%% If the memory usage exceeds this level, the process is terminated. +-define(OVERLOAD_KILL_MEM_SIZE, 3000000). + +%% This is the default time to wait before restarting and accepting +%% new requests. The value 'infinity' disables restarts. +-define(OVERLOAD_KILL_RESTART_AFTER, 5000). + +%% This is the time in milliseconds after last load message received +%% that we notify the callback about being idle. +-define(IDLE_DETECT_TIME, 100). + +%%%----------------------------------------------------------------- +%%% Overload protection macros + +-define(timestamp(), erlang:monotonic_time(microsecond)). + +-define(get_mode(Tid), + case ets:lookup(Tid, mode) of + [{mode,M}] -> M; + _ -> async + end). + +-define(set_mode(Tid, M), + begin ets:insert(Tid, {mode,M}), M end). + +-define(change_mode(Tid, M0, M1), + if M0 == M1 -> + M0; + true -> + ets:insert(Tid, {mode,M1}), + M1 + end). + +-define(max(X1, X2), + if + X2 == undefined -> X1; + X2 > X1 -> X2; + true -> X1 + end). + +-define(diff_time(OS_T1, OS_T0), OS_T1-OS_T0). + +%%%----------------------------------------------------------------- +%%% These macros enable statistics counters in the state of the +%%% process, which is useful for analysing the overload protection +%%% behaviour. These counters should not be included in code to be +%%% officially released (as some counters will grow very large over +%%% time). + +%% -define(SAVE_STATS, true). +-ifdef(SAVE_STATS). + -define(merge_with_stats(STATE), + begin + TIME = ?timestamp(), + STATE#{start => TIME, time => {TIME,0}, + flushes => 0, flushed => 0, drops => 0, + burst_drops => 0, casts => 0, calls => 0, + writes => 0, max_qlen => 0, max_time => 0, + freq => {TIME,0,0}} end). + + -define(update_max_qlen(QLEN, STATE), + begin #{max_qlen := QLEN0} = STATE, + STATE#{max_qlen => ?max(QLEN0,QLEN)} end). + + -define(update_calls_or_casts(CALL_OR_CAST, INC, STATE), + case CALL_OR_CAST of + cast -> + #{casts := CASTS0} = STATE, + STATE#{casts => CASTS0+INC}; + call -> + #{calls := CALLS0} = STATE, + STATE#{calls => CALLS0+INC} + end). + + -define(update_max_time(TIME, STATE), + begin #{max_time := TIME0} = STATE, + STATE#{max_time => ?max(TIME0,TIME)} end). + + -define(update_other(OTHER, VAR, INCVAL, STATE), + begin #{OTHER := VAR} = STATE, + STATE#{OTHER => VAR+INCVAL} end). + + -define(update_freq(TIME,STATE), + begin + case STATE of + #{freq := {START, 49, _}} -> + STATE#{freq => {TIME, 0, trunc(1000000*50/(?diff_time(TIME,START)))}}; + #{freq := {START, N, FREQ}} -> + STATE#{freq => {START, N+1, FREQ}} + end end). + + -define(update_time(TIME,STATE), + begin #{start := START} = STATE, + STATE#{time => {TIME,trunc((?diff_time(TIME,START))/1000000)}} end). + +-else. % DEFAULT! + -define(merge_with_stats(STATE), STATE). + -define(update_max_qlen(_QLEN, STATE), STATE). + -define(update_calls_or_casts(_CALL_OR_CAST, _INC, STATE), STATE). + -define(update_max_time(_TIME, STATE), STATE). + -define(update_other(_OTHER, _VAR, _INCVAL, STATE), STATE). + -define(update_freq(_TIME, STATE), STATE). + -define(update_time(_TIME, STATE), STATE). +-endif. + +%%%----------------------------------------------------------------- +%%% These macros enable callbacks that make it possible to analyse the +%%% overload protection behaviour from outside the process (including +%%% dropped requests on the client side). An external callback module +%%% (?OBSERVER_MOD) is required which is not part of the kernel +%%% application. For this reason, these callbacks should not be +%%% included in code to be officially released. + +%%-define(OBSERVER_MOD, logger_test). +-ifdef(OBSERVER_MOD). + -define(start_observation(NAME), ?OBSERVER:start_observation(NAME)). + -define(observe(NAME,EVENT), ?OBSERVER:observe(NAME,EVENT)). + +-else. % DEFAULT! + -define(start_observation(_NAME), ok). + -define(observe(_NAME,_EVENT), ok). +-endif. |