Not logging to file

[madtrick]

Hi,

I have just started to play with Lager so probably I'm doing something but I'm no able to log to file.

My setup:

• I have included the lager_transform directive in rebar.config

• I have copied the lager app config to my app.config

  [
  {lager, [
    {handlers, [
      {lager_console_backend, info},
      {lager_file_backend, [
        {"info.log", info, 0, "", 5},
        {"debug.log", debug, 0, "", 5}
      ]}
    ]}
  ]}
  ].

• Inside my code I have several calls to lager

  handle_cast(_, State) ->
  %lager:error("Error msg"),
  lager:info("Info msg"),
  lager:debug("Debug msg"),
  lager:warning("Warming msg"),
  {noreply, State}.

I have an escript script to run a quick test:

 main(_) ->
  inets:start(),
  lager:start(),
  {ok, Worker} = qrauth_worker:start_link(),
  qrauth_worker:request(Worker).

Inside qrauth_worker:request/1 I do a gen_server:cast which is handled by the code above.

When I run the escript this is the output in the console:

>>./worker 
11:07:35.394 [info] Application lager started on node nonode@nohost
11:07:35.399 [info] Application amqp_client started on node nonode@nohost
11:07:35.443 [info] Info msg
11:07:35.443 [warning] Warming msg

Which is the expected output according to my lager statements and my lager config.

But my info.log and debug.log files are empty.

To make things a bit more weird for me, if I include a lager:error statement this one flushes the log to the files but fails to output the error msg to the console.

This is the code with the lager:error

handle_cast(_, State) ->
  lager:info("Info msg"),
  lager:debug("Debug msg"),
  lager:warning("Warming msg"),
  lager:error("Error msg"),
  {noreply, State}.

This is the console output

>>./worker 
11:07:35.394 [info] Application lager started on node nonode@nohost
11:07:35.399 [info] Application amqp_client started on node nonode@nohost
11:07:35.443 [info] Info msg
11:07:35.443 [warning] Warming msg

Notice that the [error] log is missing in the console output

And this is my info.log

>>cat info.log 
2012-07-14 11:17:24.379 [info] <0.6.0> Application lager started on node nonode@nohost
2012-07-14 11:17:24.384 [info] <0.6.0> Application amqp_client started on node nonode@nohost
2012-07-14 11:17:24.424 [info] <0.75.0>@qrauth_worker:init:62 Starting worker
2012-07-14 11:17:24.434 [info] <0.75.0>@qrauth_worker:handle_cast:93 Info msg
2012-07-14 11:17:24.434 [warning] <0.75.0>@qrauth_worker:handle_cast:95 Warming msg
2012-07-14 11:17:24.435 [error] <0.75.0>@qrauth_worker:handle_cast:96 Error msg

Any hints or ideas. Thanks

[Vagabond]

My best guess is that your escript is exiting before everything is flushed to disk and/or the console. The [error] loglevel forces a fdatasync, so that is why it makes your logs suddenly work, but there's no way to force a flush to the console.

[Vagabond]

Closing due to inactivity.