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Posted to commits@couchdb.apache.org by Jan Lehnardt <ja...@apache.org> on 2012/11/01 12:41:11 UTC

Re: git commit: Module Level Logging

On Nov 1, 2012, at 00:05 , Paul Davis <pa...@gmail.com> wrote:

> Clever. Though I worry a bit about turning each log statement into two
> ets lookups in the common case. We could look into mochiweb_global.erl
> or similar that would turn that try/etc/catch/ets into a single
> function call.

Thanks for the review!

Each request already makes several requests to ets for stats. Do you
think two more make a big difference?

I’ll have a look at mochiweb_global.erl and see how I can apply that.

Cheers
Jan
-- 

> 
> On Wed, Oct 31, 2012 at 2:24 PM,  <ja...@apache.org> wrote:
>> Updated Branches:
>>  refs/heads/1585-feature-per-module-log-levels [created] 72a9f86db
>> 
>> 
>> Module Level Logging
>> 
>> With this patch, you can set log levels per CouchDB module that
>> overrides the default set in `[log] level = `.
>> 
>> For example:
>> 
>>    [log]
>>    level = info
>> 
>>    [log_level_by_module]
>>    couch_httpd = debug
>> 
>> This will have all modules log at level 'info' and `couch_httpd` log
>> at level 'debug'.
>> 
>> See src/*/*.erl for the various CouchDB modules.
>> 
>> Based on work started by Robert Newson.
>> 
>> 
>> Project: http://git-wip-us.apache.org/repos/asf/couchdb/repo
>> Commit: http://git-wip-us.apache.org/repos/asf/couchdb/commit/72a9f86d
>> Tree: http://git-wip-us.apache.org/repos/asf/couchdb/tree/72a9f86d
>> Diff: http://git-wip-us.apache.org/repos/asf/couchdb/diff/72a9f86d
>> 
>> Branch: refs/heads/1585-feature-per-module-log-levels
>> Commit: 72a9f86db8479f91388773c4a712e9626f468e54
>> Parents: 8ccf696
>> Author: Jan Lehnardt <ja...@apache.org>
>> Authored: Fri Oct 26 20:12:06 2012 +0200
>> Committer: Jan Lehnardt <ja...@apache.org>
>> Committed: Wed Oct 31 19:00:36 2012 +0100
>> 
>> ----------------------------------------------------------------------
>> etc/couchdb/local.ini     |    7 ++++++
>> src/couchdb/couch_db.hrl  |    4 +-
>> src/couchdb/couch_log.erl |   43 ++++++++++++++++++++++++++++++++++++---
>> 3 files changed, 48 insertions(+), 6 deletions(-)
>> ----------------------------------------------------------------------
>> 
>> 
>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/72a9f86d/etc/couchdb/local.ini
>> ----------------------------------------------------------------------
>> diff --git a/etc/couchdb/local.ini b/etc/couchdb/local.ini
>> index 9e711e1..a5db26f 100644
>> --- a/etc/couchdb/local.ini
>> +++ b/etc/couchdb/local.ini
>> @@ -37,6 +37,13 @@
>> [log]
>> ;level = debug
>> 
>> +[log_level_by_module]
>> +; In this section you can specify any of the four log levels 'none', 'info',
>> +; 'error' or 'debug' on a per-module basis. See src/*/*.erl for various
>> +; modules.
>> +;couch_httpd = error
>> +
>> +
>> [os_daemons]
>> ; For any commands listed here, CouchDB will attempt to ensure that
>> ; the process remains alive. Daemons should monitor their environment
>> 
>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/72a9f86d/src/couchdb/couch_db.hrl
>> ----------------------------------------------------------------------
>> diff --git a/src/couchdb/couch_db.hrl b/src/couchdb/couch_db.hrl
>> index 65eb7f0..325fb98 100644
>> --- a/src/couchdb/couch_db.hrl
>> +++ b/src/couchdb/couch_db.hrl
>> @@ -37,14 +37,14 @@
>> -define(DEFAULT_ATTACHMENT_CONTENT_TYPE, <<"application/octet-stream">>).
>> 
>> -define(LOG_DEBUG(Format, Args),
>> -    case couch_log:debug_on() of
>> +    case couch_log:debug_on(?MODULE) of
>>         true ->
>>             couch_log:debug(Format, Args);
>>         false -> ok
>>     end).
>> 
>> -define(LOG_INFO(Format, Args),
>> -    case couch_log:info_on() of
>> +    case couch_log:info_on(?MODULE) of
>>         true ->
>>             couch_log:info(Format, Args);
>>         false -> ok
>> 
>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/72a9f86d/src/couchdb/couch_log.erl
>> ----------------------------------------------------------------------
>> diff --git a/src/couchdb/couch_log.erl b/src/couchdb/couch_log.erl
>> index fc7b393..047a4d4 100644
>> --- a/src/couchdb/couch_log.erl
>> +++ b/src/couchdb/couch_log.erl
>> @@ -17,6 +17,7 @@
>> -export([start_link/0, stop/0]).
>> -export([debug/2, info/2, error/2]).
>> -export([debug_on/0, info_on/0, get_level/0, get_level_integer/0, set_level/1]).
>> +-export([debug_on/1, info_on/1, get_level/1, get_level_integer/1, set_level/2]).
>> -export([read/2]).
>> 
>> % gen_event callbacks
>> @@ -73,18 +74,26 @@ init([]) ->
>>         ("log", "level") ->
>>             ?MODULE:stop();
>>         ("log", "include_sasl") ->
>> +            ?MODULE:stop();
>> +        ("log_level_by_module", _) ->
>>             ?MODULE:stop()
>>         end),
>> 
>>     Filename = couch_config:get("log", "file", "couchdb.log"),
>>     Level = level_integer(list_to_atom(couch_config:get("log", "level", "info"))),
>>     Sasl = couch_config:get("log", "include_sasl", "true") =:= "true",
>> +    LevelByModule = couch_config:get("log_level_by_module"),
>> 
>>     case ets:info(?MODULE) of
>>     undefined -> ets:new(?MODULE, [named_table]);
>>     _ -> ok
>>     end,
>>     ets:insert(?MODULE, {level, Level}),
>> +    lists:foreach(fun({Module, ModuleLevel}) ->
>> +        ModuleLevelInteger = level_integer(list_to_atom(ModuleLevel)),
>> +        ets:insert(?MODULE, {Module, ModuleLevelInteger})
>> +    end, LevelByModule),
>> +
>> 
>>     case file:open(Filename, [append]) of
>>     {ok, Fd} ->
>> @@ -101,12 +110,24 @@ debug_on() ->
>> info_on() ->
>>     get_level_integer() =< ?LEVEL_INFO.
>> 
>> +debug_on(Module) ->
>> +    get_level_integer(Module) =< ?LEVEL_DEBUG.
>> +
>> +info_on(Module) ->
>> +    get_level_integer(Module) =< ?LEVEL_INFO.
>> +
>> set_level(LevelAtom) ->
>>     set_level_integer(level_integer(LevelAtom)).
>> 
>> +set_level(Module, LevelAtom) ->
>> +    set_level_integer(Module, level_integer(LevelAtom)).
>> +
>> get_level() ->
>>     level_atom(get_level_integer()).
>> 
>> +get_level(Module) ->
>> +    level_atom(get_level_integer(Module)).
>> +
>> get_level_integer() ->
>>     try
>>         ets:lookup_element(?MODULE, level, 2)
>> @@ -114,18 +135,28 @@ get_level_integer() ->
>>         ?LEVEL_ERROR
>>     end.
>> 
>> +get_level_integer(Module0) ->
>> +    Module = atom_to_list(Module0),
>> +    try
>> +        [{_Module, Level}] = ets:lookup(?MODULE, Module),
>> +        Level
>> +    catch error:_ ->
>> +        get_level_integer()
>> +    end.
>> +
>> set_level_integer(Int) ->
>>     gen_event:call(error_logger, couch_log, {set_level_integer, Int}).
>> 
>> +set_level_integer(Module, Int) ->
>> +    gen_event:call(error_logger, couch_log, {set_level_integer, Module, Int}).
>> +
>> handle_event({couch_error, ConMsg, FileMsg}, State) ->
>>     log(State, ConMsg, FileMsg),
>>     {ok, State};
>> -handle_event({couch_info, ConMsg, FileMsg}, #state{level = LogLevel} = State)
>> -when LogLevel =< ?LEVEL_INFO ->
>> +handle_event({couch_info, ConMsg, FileMsg}, #state{level = LogLevel} = State) ->
>>     log(State, ConMsg, FileMsg),
>>     {ok, State};
>> -handle_event({couch_debug, ConMsg, FileMsg}, #state{level = LogLevel} = State)
>> -when LogLevel =< ?LEVEL_DEBUG ->
>> +handle_event({couch_debug, ConMsg, FileMsg}, #state{level = LogLevel} = State) ->
>>     log(State, ConMsg, FileMsg),
>>     {ok, State};
>> handle_event({error_report, _, {Pid, _, _}}=Event, #state{sasl = true} = St) ->
>> @@ -141,6 +172,10 @@ handle_event(_Event, State) ->
>> 
>> handle_call({set_level_integer, NewLevel}, State) ->
>>     ets:insert(?MODULE, {level, NewLevel}),
>> +    {ok, ok, State#state{level = NewLevel}};
>> +
>> +handle_call({set_level_integer, Module, NewLevel}, State) ->
>> +    ets:insert(?MODULE, {Module, NewLevel}),
>>     {ok, ok, State#state{level = NewLevel}}.
>> 
>> handle_info(_Info, State) ->
>> 


Re: git commit: Module Level Logging

Posted by Jan Lehnardt <ja...@apache.org>.
Sweet, thanks! :)

On Nov 1, 2012, at 17:49 , Paul Davis <pa...@gmail.com> wrote:

> I should've been more clear that I don't think this is a blocker, I
> just wanted to make a note that the common case was going to end up
> being to ets tables (assuming most people don't list nearly every
> module with a custom format). The mochiglobal approach is easy enough
> that we can drop in a replacement in the future without an API change
> so I'm not worried about letting this through given how useful it
> looks.
> 
> On Thu, Nov 1, 2012 at 7:41 AM, Jan Lehnardt <ja...@apache.org> wrote:
>> 
>> On Nov 1, 2012, at 00:05 , Paul Davis <pa...@gmail.com> wrote:
>> 
>>> Clever. Though I worry a bit about turning each log statement into two
>>> ets lookups in the common case. We could look into mochiweb_global.erl
>>> or similar that would turn that try/etc/catch/ets into a single
>>> function call.
>> 
>> Thanks for the review!
>> 
>> Each request already makes several requests to ets for stats. Do you
>> think two more make a big difference?
>> 
>> I’ll have a look at mochiweb_global.erl and see how I can apply that.
>> 
>> Cheers
>> Jan
>> --
>> 
>>> 
>>> On Wed, Oct 31, 2012 at 2:24 PM,  <ja...@apache.org> wrote:
>>>> Updated Branches:
>>>> refs/heads/1585-feature-per-module-log-levels [created] 72a9f86db
>>>> 
>>>> 
>>>> Module Level Logging
>>>> 
>>>> With this patch, you can set log levels per CouchDB module that
>>>> overrides the default set in `[log] level = `.
>>>> 
>>>> For example:
>>>> 
>>>>   [log]
>>>>   level = info
>>>> 
>>>>   [log_level_by_module]
>>>>   couch_httpd = debug
>>>> 
>>>> This will have all modules log at level 'info' and `couch_httpd` log
>>>> at level 'debug'.
>>>> 
>>>> See src/*/*.erl for the various CouchDB modules.
>>>> 
>>>> Based on work started by Robert Newson.
>>>> 
>>>> 
>>>> Project: http://git-wip-us.apache.org/repos/asf/couchdb/repo
>>>> Commit: http://git-wip-us.apache.org/repos/asf/couchdb/commit/72a9f86d
>>>> Tree: http://git-wip-us.apache.org/repos/asf/couchdb/tree/72a9f86d
>>>> Diff: http://git-wip-us.apache.org/repos/asf/couchdb/diff/72a9f86d
>>>> 
>>>> Branch: refs/heads/1585-feature-per-module-log-levels
>>>> Commit: 72a9f86db8479f91388773c4a712e9626f468e54
>>>> Parents: 8ccf696
>>>> Author: Jan Lehnardt <ja...@apache.org>
>>>> Authored: Fri Oct 26 20:12:06 2012 +0200
>>>> Committer: Jan Lehnardt <ja...@apache.org>
>>>> Committed: Wed Oct 31 19:00:36 2012 +0100
>>>> 
>>>> ----------------------------------------------------------------------
>>>> etc/couchdb/local.ini     |    7 ++++++
>>>> src/couchdb/couch_db.hrl  |    4 +-
>>>> src/couchdb/couch_log.erl |   43 ++++++++++++++++++++++++++++++++++++---
>>>> 3 files changed, 48 insertions(+), 6 deletions(-)
>>>> ----------------------------------------------------------------------
>>>> 
>>>> 
>>>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/72a9f86d/etc/couchdb/local.ini
>>>> ----------------------------------------------------------------------
>>>> diff --git a/etc/couchdb/local.ini b/etc/couchdb/local.ini
>>>> index 9e711e1..a5db26f 100644
>>>> --- a/etc/couchdb/local.ini
>>>> +++ b/etc/couchdb/local.ini
>>>> @@ -37,6 +37,13 @@
>>>> [log]
>>>> ;level = debug
>>>> 
>>>> +[log_level_by_module]
>>>> +; In this section you can specify any of the four log levels 'none', 'info',
>>>> +; 'error' or 'debug' on a per-module basis. See src/*/*.erl for various
>>>> +; modules.
>>>> +;couch_httpd = error
>>>> +
>>>> +
>>>> [os_daemons]
>>>> ; For any commands listed here, CouchDB will attempt to ensure that
>>>> ; the process remains alive. Daemons should monitor their environment
>>>> 
>>>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/72a9f86d/src/couchdb/couch_db.hrl
>>>> ----------------------------------------------------------------------
>>>> diff --git a/src/couchdb/couch_db.hrl b/src/couchdb/couch_db.hrl
>>>> index 65eb7f0..325fb98 100644
>>>> --- a/src/couchdb/couch_db.hrl
>>>> +++ b/src/couchdb/couch_db.hrl
>>>> @@ -37,14 +37,14 @@
>>>> -define(DEFAULT_ATTACHMENT_CONTENT_TYPE, <<"application/octet-stream">>).
>>>> 
>>>> -define(LOG_DEBUG(Format, Args),
>>>> -    case couch_log:debug_on() of
>>>> +    case couch_log:debug_on(?MODULE) of
>>>>        true ->
>>>>            couch_log:debug(Format, Args);
>>>>        false -> ok
>>>>    end).
>>>> 
>>>> -define(LOG_INFO(Format, Args),
>>>> -    case couch_log:info_on() of
>>>> +    case couch_log:info_on(?MODULE) of
>>>>        true ->
>>>>            couch_log:info(Format, Args);
>>>>        false -> ok
>>>> 
>>>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/72a9f86d/src/couchdb/couch_log.erl
>>>> ----------------------------------------------------------------------
>>>> diff --git a/src/couchdb/couch_log.erl b/src/couchdb/couch_log.erl
>>>> index fc7b393..047a4d4 100644
>>>> --- a/src/couchdb/couch_log.erl
>>>> +++ b/src/couchdb/couch_log.erl
>>>> @@ -17,6 +17,7 @@
>>>> -export([start_link/0, stop/0]).
>>>> -export([debug/2, info/2, error/2]).
>>>> -export([debug_on/0, info_on/0, get_level/0, get_level_integer/0, set_level/1]).
>>>> +-export([debug_on/1, info_on/1, get_level/1, get_level_integer/1, set_level/2]).
>>>> -export([read/2]).
>>>> 
>>>> % gen_event callbacks
>>>> @@ -73,18 +74,26 @@ init([]) ->
>>>>        ("log", "level") ->
>>>>            ?MODULE:stop();
>>>>        ("log", "include_sasl") ->
>>>> +            ?MODULE:stop();
>>>> +        ("log_level_by_module", _) ->
>>>>            ?MODULE:stop()
>>>>        end),
>>>> 
>>>>    Filename = couch_config:get("log", "file", "couchdb.log"),
>>>>    Level = level_integer(list_to_atom(couch_config:get("log", "level", "info"))),
>>>>    Sasl = couch_config:get("log", "include_sasl", "true") =:= "true",
>>>> +    LevelByModule = couch_config:get("log_level_by_module"),
>>>> 
>>>>    case ets:info(?MODULE) of
>>>>    undefined -> ets:new(?MODULE, [named_table]);
>>>>    _ -> ok
>>>>    end,
>>>>    ets:insert(?MODULE, {level, Level}),
>>>> +    lists:foreach(fun({Module, ModuleLevel}) ->
>>>> +        ModuleLevelInteger = level_integer(list_to_atom(ModuleLevel)),
>>>> +        ets:insert(?MODULE, {Module, ModuleLevelInteger})
>>>> +    end, LevelByModule),
>>>> +
>>>> 
>>>>    case file:open(Filename, [append]) of
>>>>    {ok, Fd} ->
>>>> @@ -101,12 +110,24 @@ debug_on() ->
>>>> info_on() ->
>>>>    get_level_integer() =< ?LEVEL_INFO.
>>>> 
>>>> +debug_on(Module) ->
>>>> +    get_level_integer(Module) =< ?LEVEL_DEBUG.
>>>> +
>>>> +info_on(Module) ->
>>>> +    get_level_integer(Module) =< ?LEVEL_INFO.
>>>> +
>>>> set_level(LevelAtom) ->
>>>>    set_level_integer(level_integer(LevelAtom)).
>>>> 
>>>> +set_level(Module, LevelAtom) ->
>>>> +    set_level_integer(Module, level_integer(LevelAtom)).
>>>> +
>>>> get_level() ->
>>>>    level_atom(get_level_integer()).
>>>> 
>>>> +get_level(Module) ->
>>>> +    level_atom(get_level_integer(Module)).
>>>> +
>>>> get_level_integer() ->
>>>>    try
>>>>        ets:lookup_element(?MODULE, level, 2)
>>>> @@ -114,18 +135,28 @@ get_level_integer() ->
>>>>        ?LEVEL_ERROR
>>>>    end.
>>>> 
>>>> +get_level_integer(Module0) ->
>>>> +    Module = atom_to_list(Module0),
>>>> +    try
>>>> +        [{_Module, Level}] = ets:lookup(?MODULE, Module),
>>>> +        Level
>>>> +    catch error:_ ->
>>>> +        get_level_integer()
>>>> +    end.
>>>> +
>>>> set_level_integer(Int) ->
>>>>    gen_event:call(error_logger, couch_log, {set_level_integer, Int}).
>>>> 
>>>> +set_level_integer(Module, Int) ->
>>>> +    gen_event:call(error_logger, couch_log, {set_level_integer, Module, Int}).
>>>> +
>>>> handle_event({couch_error, ConMsg, FileMsg}, State) ->
>>>>    log(State, ConMsg, FileMsg),
>>>>    {ok, State};
>>>> -handle_event({couch_info, ConMsg, FileMsg}, #state{level = LogLevel} = State)
>>>> -when LogLevel =< ?LEVEL_INFO ->
>>>> +handle_event({couch_info, ConMsg, FileMsg}, #state{level = LogLevel} = State) ->
>>>>    log(State, ConMsg, FileMsg),
>>>>    {ok, State};
>>>> -handle_event({couch_debug, ConMsg, FileMsg}, #state{level = LogLevel} = State)
>>>> -when LogLevel =< ?LEVEL_DEBUG ->
>>>> +handle_event({couch_debug, ConMsg, FileMsg}, #state{level = LogLevel} = State) ->
>>>>    log(State, ConMsg, FileMsg),
>>>>    {ok, State};
>>>> handle_event({error_report, _, {Pid, _, _}}=Event, #state{sasl = true} = St) ->
>>>> @@ -141,6 +172,10 @@ handle_event(_Event, State) ->
>>>> 
>>>> handle_call({set_level_integer, NewLevel}, State) ->
>>>>    ets:insert(?MODULE, {level, NewLevel}),
>>>> +    {ok, ok, State#state{level = NewLevel}};
>>>> +
>>>> +handle_call({set_level_integer, Module, NewLevel}, State) ->
>>>> +    ets:insert(?MODULE, {Module, NewLevel}),
>>>>    {ok, ok, State#state{level = NewLevel}}.
>>>> 
>>>> handle_info(_Info, State) ->
>>>> 
>> 


Re: git commit: Module Level Logging

Posted by Paul Davis <pa...@gmail.com>.
I should've been more clear that I don't think this is a blocker, I
just wanted to make a note that the common case was going to end up
being to ets tables (assuming most people don't list nearly every
module with a custom format). The mochiglobal approach is easy enough
that we can drop in a replacement in the future without an API change
so I'm not worried about letting this through given how useful it
looks.

On Thu, Nov 1, 2012 at 7:41 AM, Jan Lehnardt <ja...@apache.org> wrote:
>
> On Nov 1, 2012, at 00:05 , Paul Davis <pa...@gmail.com> wrote:
>
>> Clever. Though I worry a bit about turning each log statement into two
>> ets lookups in the common case. We could look into mochiweb_global.erl
>> or similar that would turn that try/etc/catch/ets into a single
>> function call.
>
> Thanks for the review!
>
> Each request already makes several requests to ets for stats. Do you
> think two more make a big difference?
>
> I’ll have a look at mochiweb_global.erl and see how I can apply that.
>
> Cheers
> Jan
> --
>
>>
>> On Wed, Oct 31, 2012 at 2:24 PM,  <ja...@apache.org> wrote:
>>> Updated Branches:
>>>  refs/heads/1585-feature-per-module-log-levels [created] 72a9f86db
>>>
>>>
>>> Module Level Logging
>>>
>>> With this patch, you can set log levels per CouchDB module that
>>> overrides the default set in `[log] level = `.
>>>
>>> For example:
>>>
>>>    [log]
>>>    level = info
>>>
>>>    [log_level_by_module]
>>>    couch_httpd = debug
>>>
>>> This will have all modules log at level 'info' and `couch_httpd` log
>>> at level 'debug'.
>>>
>>> See src/*/*.erl for the various CouchDB modules.
>>>
>>> Based on work started by Robert Newson.
>>>
>>>
>>> Project: http://git-wip-us.apache.org/repos/asf/couchdb/repo
>>> Commit: http://git-wip-us.apache.org/repos/asf/couchdb/commit/72a9f86d
>>> Tree: http://git-wip-us.apache.org/repos/asf/couchdb/tree/72a9f86d
>>> Diff: http://git-wip-us.apache.org/repos/asf/couchdb/diff/72a9f86d
>>>
>>> Branch: refs/heads/1585-feature-per-module-log-levels
>>> Commit: 72a9f86db8479f91388773c4a712e9626f468e54
>>> Parents: 8ccf696
>>> Author: Jan Lehnardt <ja...@apache.org>
>>> Authored: Fri Oct 26 20:12:06 2012 +0200
>>> Committer: Jan Lehnardt <ja...@apache.org>
>>> Committed: Wed Oct 31 19:00:36 2012 +0100
>>>
>>> ----------------------------------------------------------------------
>>> etc/couchdb/local.ini     |    7 ++++++
>>> src/couchdb/couch_db.hrl  |    4 +-
>>> src/couchdb/couch_log.erl |   43 ++++++++++++++++++++++++++++++++++++---
>>> 3 files changed, 48 insertions(+), 6 deletions(-)
>>> ----------------------------------------------------------------------
>>>
>>>
>>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/72a9f86d/etc/couchdb/local.ini
>>> ----------------------------------------------------------------------
>>> diff --git a/etc/couchdb/local.ini b/etc/couchdb/local.ini
>>> index 9e711e1..a5db26f 100644
>>> --- a/etc/couchdb/local.ini
>>> +++ b/etc/couchdb/local.ini
>>> @@ -37,6 +37,13 @@
>>> [log]
>>> ;level = debug
>>>
>>> +[log_level_by_module]
>>> +; In this section you can specify any of the four log levels 'none', 'info',
>>> +; 'error' or 'debug' on a per-module basis. See src/*/*.erl for various
>>> +; modules.
>>> +;couch_httpd = error
>>> +
>>> +
>>> [os_daemons]
>>> ; For any commands listed here, CouchDB will attempt to ensure that
>>> ; the process remains alive. Daemons should monitor their environment
>>>
>>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/72a9f86d/src/couchdb/couch_db.hrl
>>> ----------------------------------------------------------------------
>>> diff --git a/src/couchdb/couch_db.hrl b/src/couchdb/couch_db.hrl
>>> index 65eb7f0..325fb98 100644
>>> --- a/src/couchdb/couch_db.hrl
>>> +++ b/src/couchdb/couch_db.hrl
>>> @@ -37,14 +37,14 @@
>>> -define(DEFAULT_ATTACHMENT_CONTENT_TYPE, <<"application/octet-stream">>).
>>>
>>> -define(LOG_DEBUG(Format, Args),
>>> -    case couch_log:debug_on() of
>>> +    case couch_log:debug_on(?MODULE) of
>>>         true ->
>>>             couch_log:debug(Format, Args);
>>>         false -> ok
>>>     end).
>>>
>>> -define(LOG_INFO(Format, Args),
>>> -    case couch_log:info_on() of
>>> +    case couch_log:info_on(?MODULE) of
>>>         true ->
>>>             couch_log:info(Format, Args);
>>>         false -> ok
>>>
>>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/72a9f86d/src/couchdb/couch_log.erl
>>> ----------------------------------------------------------------------
>>> diff --git a/src/couchdb/couch_log.erl b/src/couchdb/couch_log.erl
>>> index fc7b393..047a4d4 100644
>>> --- a/src/couchdb/couch_log.erl
>>> +++ b/src/couchdb/couch_log.erl
>>> @@ -17,6 +17,7 @@
>>> -export([start_link/0, stop/0]).
>>> -export([debug/2, info/2, error/2]).
>>> -export([debug_on/0, info_on/0, get_level/0, get_level_integer/0, set_level/1]).
>>> +-export([debug_on/1, info_on/1, get_level/1, get_level_integer/1, set_level/2]).
>>> -export([read/2]).
>>>
>>> % gen_event callbacks
>>> @@ -73,18 +74,26 @@ init([]) ->
>>>         ("log", "level") ->
>>>             ?MODULE:stop();
>>>         ("log", "include_sasl") ->
>>> +            ?MODULE:stop();
>>> +        ("log_level_by_module", _) ->
>>>             ?MODULE:stop()
>>>         end),
>>>
>>>     Filename = couch_config:get("log", "file", "couchdb.log"),
>>>     Level = level_integer(list_to_atom(couch_config:get("log", "level", "info"))),
>>>     Sasl = couch_config:get("log", "include_sasl", "true") =:= "true",
>>> +    LevelByModule = couch_config:get("log_level_by_module"),
>>>
>>>     case ets:info(?MODULE) of
>>>     undefined -> ets:new(?MODULE, [named_table]);
>>>     _ -> ok
>>>     end,
>>>     ets:insert(?MODULE, {level, Level}),
>>> +    lists:foreach(fun({Module, ModuleLevel}) ->
>>> +        ModuleLevelInteger = level_integer(list_to_atom(ModuleLevel)),
>>> +        ets:insert(?MODULE, {Module, ModuleLevelInteger})
>>> +    end, LevelByModule),
>>> +
>>>
>>>     case file:open(Filename, [append]) of
>>>     {ok, Fd} ->
>>> @@ -101,12 +110,24 @@ debug_on() ->
>>> info_on() ->
>>>     get_level_integer() =< ?LEVEL_INFO.
>>>
>>> +debug_on(Module) ->
>>> +    get_level_integer(Module) =< ?LEVEL_DEBUG.
>>> +
>>> +info_on(Module) ->
>>> +    get_level_integer(Module) =< ?LEVEL_INFO.
>>> +
>>> set_level(LevelAtom) ->
>>>     set_level_integer(level_integer(LevelAtom)).
>>>
>>> +set_level(Module, LevelAtom) ->
>>> +    set_level_integer(Module, level_integer(LevelAtom)).
>>> +
>>> get_level() ->
>>>     level_atom(get_level_integer()).
>>>
>>> +get_level(Module) ->
>>> +    level_atom(get_level_integer(Module)).
>>> +
>>> get_level_integer() ->
>>>     try
>>>         ets:lookup_element(?MODULE, level, 2)
>>> @@ -114,18 +135,28 @@ get_level_integer() ->
>>>         ?LEVEL_ERROR
>>>     end.
>>>
>>> +get_level_integer(Module0) ->
>>> +    Module = atom_to_list(Module0),
>>> +    try
>>> +        [{_Module, Level}] = ets:lookup(?MODULE, Module),
>>> +        Level
>>> +    catch error:_ ->
>>> +        get_level_integer()
>>> +    end.
>>> +
>>> set_level_integer(Int) ->
>>>     gen_event:call(error_logger, couch_log, {set_level_integer, Int}).
>>>
>>> +set_level_integer(Module, Int) ->
>>> +    gen_event:call(error_logger, couch_log, {set_level_integer, Module, Int}).
>>> +
>>> handle_event({couch_error, ConMsg, FileMsg}, State) ->
>>>     log(State, ConMsg, FileMsg),
>>>     {ok, State};
>>> -handle_event({couch_info, ConMsg, FileMsg}, #state{level = LogLevel} = State)
>>> -when LogLevel =< ?LEVEL_INFO ->
>>> +handle_event({couch_info, ConMsg, FileMsg}, #state{level = LogLevel} = State) ->
>>>     log(State, ConMsg, FileMsg),
>>>     {ok, State};
>>> -handle_event({couch_debug, ConMsg, FileMsg}, #state{level = LogLevel} = State)
>>> -when LogLevel =< ?LEVEL_DEBUG ->
>>> +handle_event({couch_debug, ConMsg, FileMsg}, #state{level = LogLevel} = State) ->
>>>     log(State, ConMsg, FileMsg),
>>>     {ok, State};
>>> handle_event({error_report, _, {Pid, _, _}}=Event, #state{sasl = true} = St) ->
>>> @@ -141,6 +172,10 @@ handle_event(_Event, State) ->
>>>
>>> handle_call({set_level_integer, NewLevel}, State) ->
>>>     ets:insert(?MODULE, {level, NewLevel}),
>>> +    {ok, ok, State#state{level = NewLevel}};
>>> +
>>> +handle_call({set_level_integer, Module, NewLevel}, State) ->
>>> +    ets:insert(?MODULE, {Module, NewLevel}),
>>>     {ok, ok, State#state{level = NewLevel}}.
>>>
>>> handle_info(_Info, State) ->
>>>
>