עידו פרלמוטר (Ido Perlmuter)

NAME

Pye - Session-based logging platform on top of SQL/NoSQL databases

SYNOPSIS

        use Pye;

        # start logging on top of a certain backend, say Pye::MongoDB
        # (you can also call new() directly on the backend class, check
        #  out the documentation of the specific backend)

        my $pye = Pye->new('MongoDB',
                host => 'mongodb://logserver:27017',
                database => 'log_db',
                collection => 'myapp_log'
        );

        # if you've created your own backend, prefix it with a plus sign
        my $pye = Pye->new('+My::Pye::Backend', \%options);

        # now start logging
        $pye->log($session_id, "Some log message", { data => 'example data' });

DESCRIPTION

Pye is a dead-simple, session-based logging platform where all logs are stored in a database. Log messages in Pye include a date, a text message, and possibly a data structure (hash/array-ref) that "illustrates" the text.

I built Pye due to my frustration with file-based loggers that generate logs that are extremely difficult to read, analyze and maintain.

Pye is most useful for services (e.g. web apps) that handle requests, or otherwise work in sessions, but can be useful in virtually any application, including automatic (e.g. cron) scripts.

In order to use Pye, your program must define an ID for every session. "Session" can really mean anything here: a client session in a web service, a request to your web service, an execution of a script, whatever. As long as a unique ID can be generated, Pye can handle logging for you.

Main features:

  • Supporting data

    With Pye, any complex data structure (i.e. hash/array) can be attached to any log message, enabling you to illustrate a situation, display complex data, etc.

  • No log levels

    Yeah, I consider this a feature. Log levels are a bother, and I don't need them. All log messages in Pye are saved into the database, nothing gets lost.

  • Easy inspection

    Pye comes with a command line utility, pye, that offers quick inspection of the log. You can easily view a list of current/latest sessions and read the log of a specific session. No more mucking about through endless log files, trying to understand which lines belong to which session, or trying to find that area of the file with messages from that certain date your software died on.

  • Multiple backends

    Pye supports several database backends. Currently, Pye::MongoDB supports MongoDB, and Pye::SQL supports MySQL, PostgreSQL and SQLite.

This package provides two purposes. It provides a constructor that dynamically loads the requested backend class and creates an object of it. It is also a role (with Role::Tiny) detailing methods backend classes are required to implement.

UPGRADING TO v2.0.0 AND UP

Originally, Pye was purely a MongoDB logging system, and this module provided the MongoDB functionality. Since v2.0.0, Pye became a system with pluggable backends, and the MongoDB functionality was moved to Pye::MongoDB (not provided by this distribution, so you should install that too if you've been using Pye before v2.0.0).

An improvement over v1.*.* was also introduced: before, every application had two collections in the database - a log collection and a session collection. The session collection is not needed anymore. You can remove these session collections from your current database with no repercussions.

Unfortunately, the API for v2.0.0 is not backwards compatible with previous versions (but previous data is). You will probably need to make two changes:

  • In your applications, change the lines instantiating a Pye object to include the name of the backend:

            my $pye = Pye->new('MongoDB', %options);

    Alternatively, replace use Pye with use Pye::MongoDB and call:

            my $pye = Pye::MongoDB->new(%options);

    Also, in %options, the log_db option was renamed database, and log_coll was renamed table (or collection, both are supported).

  • The options for the pye command line utility have changed. You will now need to provide a -b|--backend option (with "MongoDB" as the value), and instead of -l|--log_coll you need to provide -c|--collection. Since the session collection has been deprecated, the -s|--session_coll option has been removed, and now -s is an alias for -S|--session_id.

Also note the following dependency changes:

CONSTRUCTOR

new( $backend, [ %options ] )

This is a convenience constructor to easily load a Pye backend and create a new instance of it. Pye will load the $backend supplied, and pass %options (if any) to its own constructor.

If you're writing your own backend which is not under the Pye:: namespace, prefix it with a plus sign, otherwise Pye will not find it.

REQUIRED METHODS

The following methods must be implemented by consuming classes:

log( $session_id, $text, [ \%data ] )

Log a new message, with text $text, under session ID $session_id. An optional reference can also be supplied and stored with the message.

session_log( $session_id )

Returns a list of all messages stored under session ID $session_id. Every item in the array is a hash-ref with the following keys: session_id, date in (YYYY-MM-DD format), time (in HH:MM:SS.SSS format), text and possibly data.

list_sessions( [ \%options ] )

Returns a list of sessions in the log, based on the provided options. If no options are provided, the latest 10 sessions should be returned. The following options are supported:

  • sort - how to sort sessions (every backend will accept a different value; defaults to descending order by date)

  • skip - after sorting, skip a number of sessions (defaults to 0)

  • limit - limit the number of sessions returned (defaults to 10)

Every item (i.e. session) in the list should be a hash-ref with the keys id, date (in YYYY-MM-DD format) and time (in HH:MM:SS.SSS format).

_remove_session_logs( $session_id )

Removes all messages for a specific session.

CONFIGURATION AND ENVIRONMENT

Pye requires no configuration files or environment variables.

DEPENDENCIES

Pye depends on the following CPAN modules:

The command line utility, pye, depends on:

It is recommended to install Cpanel::JSON::XS is recommended for fast JSON (de)serialization.

BUGS AND LIMITATIONS

Please report any bugs or feature requests to bug-Pye@rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Pye.

SUPPORT

You can find documentation for this module with the perldoc command.

        perldoc Pye

You can also look for information at:

AUTHOR

Ido Perlmuter <ido@ido50.net>

LICENSE AND COPYRIGHT

Copyright (c) 2013-2015, Ido Perlmuter ido@ido50.net.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either version 5.8.1 or any later version. See perlartistic and perlgpl.

The full text of the license can be found in the LICENSE file included with this module.

DISCLAIMER OF WARRANTY

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.