NAME

Helios::Logger - Base class for sending Helios logging information to external loggers

SYNOPSIS

 # in your logging system shim class
 use strict;
 use warnings;
 use base qw(Helios::Logger);
 # optional, but probably useful
 use Helios::LogEntry::Levels qw(:all);
 use Helios::Error::LoggingError;
  
 sub init {
        my $self = shift;

        ...initialization code for your logging system...
 }
 
 sub logMsg {
        my $self = shift;
        my $job = shift;
        my $priority_level = shift;
        my $log_message = shift;
        ...code to log the message to your logging system...
 }

DESCRIPTION

Helios::Logger is the base class to extend to provide interfaces to external logging systems for Helios services. It provides a basic set of accessor methods to get and store information about the Helios environment, and defines interface methods for you to override in your class to actually implement the logging code.

It should be noted that all methods are actually class methods, not instance (object) methods, because Helios::Logger subclasses are not instantiated. If you need to implement other methods outside of the interface methods defined below, make sure you implement them as class methods.

ACCESSOR METHODS

Helios::Logger provides 4 set/get accessor pairs to provide access to information from the Helios collective environment:

 set/getConfig();   # config hashref from Helios::Service->getConfig()
 set/getJobType();  # job type/service name string from Helios::Service->getJobType()
 set/getHostname(); # host job is running on from Helios::Service->getHostname()
 set/getDriver();   # Data::ObjectDriver object connected to Helios collective 
                      database from Helios::Service->getDriver()
 

Normally, Helios::Service->logMsg() calls the set* methods before the init() method to properly initialize the logging class. If these values can be adjusted in the init() method if necessary.

INTERFACE METHODS

The following methods must be implemented by your Helios::Logger subclass for external logging to work.

init()

Class method to initialize the logging code for the external logging system. This will be run once when the service daemon starts. You also can use init() to check for configuration errors or adjust configuration parameters (set/getConfig()). If your logging system doesn't need any initialization, go ahead and declare an empty init() method in your class anyway.

logMsg($job, $priority_level, $message)

Class method to send the message to the external logging system for logging. The $job parameter is a Helios::Job object, while $priority_level is an integer corresponding to one of the symbols defined in Helios::LogEntry::Levels (which are the same as Sys::Syslog's). The implementation of this method in your subclass should use the external logging system to log these values appropriately. It should throw a Helios::Error::LoggingError if it encounters an error.

NOTE: When Helios::Service->logMsg() calls this method, it is guaranteed to have three values, so when implementing this method in your subclass you don't have to worry about parameter parsing as much as the calling routine does. However, the values of $job and/or $priority_level may be undefined values, and your implementation of logMsg() will have to deal with that appropriately.

SEE ALSO

Helios::Service

AUTHOR

Andrew Johnson, <lajandy at cpan dotorg>

COPYRIGHT AND LICENSE

Copyright (C) 2009-12 by Andrew Johnson

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.0 or, at your option, any later version of Perl 5 you may have available.

WARRANTY

This software comes with no warranty of any kind.