NAME

FlightRecorder - Structured Logging

ABSTRACT

Logging for Distributed Systems

SYNOPSIS

package main;

use FlightRecorder;

my $f = FlightRecorder->new(
  auto => undef
);

# $f->begin('try');
# $f->debug('something happened');
# $f->end;

DESCRIPTION

This package provides a simple mechanism for logging events with context, serializing and distributing the event logs, and producing a transcript of activity to provide insight into the behavior of distributed systems.

INTEGRATES

This package integrates behaviors from:

Data::Object::Role::Pluggable

Data::Object::Role::Throwable

LIBRARIES

This package uses type constraints from:

Types::Standard

ATTRIBUTES

This package has the following attributes:

auto

auto(Maybe[FileHandle])

This attribute is read-only, accepts (Maybe[FileHandle]) values, and is optional.

format

format(Str)

This attribute is read-write, accepts (Str) values, and is optional.

head

head(Str)

This attribute is read-only, accepts (Str) values, and is optional.

item

item(HashRef)

This attribute is read-only, accepts (HashRef) values, and is optional.

level

level(Enum[qw(debug info warn error fatal)])

This attribute is read-only, accepts (Enum[qw(debug info warn error fatal)]) values, and is optional.

logs

logs(ArrayRef[HashRef])

This attribute is read-only, accepts (ArrayRef[HashRef]) values, and is optional.

refs

refs(HashRef)

This attribute is read-only, accepts (HashRef) values, and is optional.

METHODS

This package implements the following methods:

begin

begin(Str $label) : Object

The begin method creates and logs a new context.

• begin example #1

    # given: synopsis
  
    $f->begin('test')
  

branch

branch(Str $label) : Object

The branch method creates and returns a new FlightRecorder object which shares the event log with the parent object. This method creates a new context when called.

• branch example #1

    # given: synopsis
  
    $f->begin('test')->branch('next')
  

count

count(Maybe[Str] $level) : Int

The count method returns the total number of log entries, or the number of log entries matching the log level specified.

• count example #1

    # given: synopsis
  
    $f->begin('try')->debug('something happened')->end;
    $f->count;
  

• count example #2

    # given: synopsis
  
    $f->info('something happened');
    $f->count('info');
  

• count example #3

    # given: synopsis
  
    $f->fatal('something happened');
    $f->count('fatal');
  

data

data(HashRef[Str] $data) : Object

The data method associates arbitrary metadata with the last event.

• data example #1

    # given: synopsis
  
    $f->debug('something happened')->data({
      error => 'unknown at ./example line 10'
    });
  

debug

debug(Str @message) : Object

The debug method logs a debug level event with context.

• debug example #1

    # given: synopsis
  
    $f->debug('something happened')
  

end

end() : Object

The end method logs the end of the current context.

• end example #1

    # given: synopsis
  
    $f->begin('main')->end
  

error

error(Str @message) : Object

The error method logs an error level event with context.

• error example #1

    # given: synopsis
  
    $f->error('something happened')
  

fatal

fatal(Str @message) : Object

The fatal method logs a fatal level event with context.

• fatal example #1

    # given: synopsis
  
    $f->fatal('something happened')
  

info

info(Str @message) : Object

The info method logs an info level event with context.

• info example #1

    # given: synopsis
  
    $f->info('something happened')
  

output

output(FileHandle $handle) : Str

The output method outputs the last event using the format defined in the format attribute. This method is called automatically after each log-event if the auto attribute is set, which is by default set to STDOUT.

• output example #1

    # given: synopsis
  
    $f->begin('test')->output
  

• output example #2

    package main;
  
    use FlightRecorder;
  
    my $f = FlightRecorder->new;
  
    $f->begin('try');
  
    # $f->output
  
    $f->debug('something happened');
  
    # $f->output
  
    $f->end;
  
    # $f->output
  

report

report(Str $name, Str $level) : Object

The report method loads and returns the specified report plugin.

• report example #1

    # given: synopsis
  
    $f->report('verbose')
  

• report example #2

    # given: synopsis
  
    $f->report('succinct', 'fatal')
  

reset

reset() : Object

The reset method returns an object to its initial state.

• reset example #1

    # given: synopsis
  
    $f->begin('try')->debug('something happened')->end;
    $f->reset;
  

• reset example #2

    # given: synopsis
  
    $f->begin('try')->debug('something happened')->end;
    $f->branch('main')->switch('try')->fatal('something happened')->end;
    $f->reset;
  

serialize

serialize() : HashRef

The serialize method normalizes and serializes the event log and returns it as a hashref.

• serialize example #1

    # given: synopsis
  
    $f->begin('main')->serialize
  

simple

simple() : Object

The simple method loads and returns the FlightRecorder::Plugin::ReportSimple report plugin.

• simple example #1

    # given: synopsis
  
    $f->simple
  

succinct

succinct() : Object

The succinct method loads and returns the FlightRecorder::Plugin::ReportSuccinct report plugin.

• succinct example #1

    # given: synopsis
  
    $f->succinct
  

switch

switch(Str $name) : Object

The switch method finds and sets the current context based on the name provided.

• switch example #1

    # given: synopsis
  
    $f->begin('main')->begin('test')->switch('main')
  

verbose

verbose() : Object

The verbose method loads and returns the FlightRecorder::Plugin::ReportVerbose report plugin.

• verbose example #1

    # given: synopsis
  
    $f->verbose
  

warn

warn(Str @message) : Object

The warn method logs a warn level event with context.

• warn example #1

    # given: synopsis
  
    $f->warn('something happened')
  

AUTHOR

Al Newkirk, awncorp@cpan.org

LICENSE

Copyright (C) 2011-2019, Al Newkirk, et al.

This is free software; you can redistribute it and/or modify it under the terms of the The Apache License, Version 2.0, as elucidated in the "license file".

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