MongodbLogger:
logger for Rails 3

MongoDB is an open source, high-performance, schema-free, document-oriented database. Features:

• Consistent UTF-8 encoding;
• Cross-platform support;
• Efficient storage for large binary data;
• Replication and failover;
• MapReduce;

MongodbLogger: Installation

• Add to Gemfile
  

  gem "mongodb_logger"

• Add to ApplicationController
  

  include MongodbLogger::Base

• Setup config for MongoDB;
• Setup front end. Add to config/routes.rb

  require 'mongodb_logger/server'
  mount MongodbLogger::Server.new, :at => "/mongodb"

MongodbLogger: log structure

{
    'action'           : action_name,
    'application_name' : application_name (rails project name),
    'controller'       : controller_name,
    'ip'               : ip_address,
    'messages'         : {
                           'info'  : [ ],
                           'debug' : [ ],
                           'error' : [ ],
                           'warn'  : [ ],
                           'fatal' : [ ]
                         },
    'params'           : { },
    'path'             : path,
    'request_time'     : date_of_request,
    'runtime'          : elapsed_execution_time_in_milliseconds,
    'url'              : full_url,
    'method'           : request method (GET, POST, OPTIONS),
    'is_exception'     : true only for exceptions (in other cases this field miss)
}

MongodbLogger: add extra information to log

# make sure we're using the MongodbLogger in this environment
if Rails.logger.respond_to?(:add_metadata)
 Rails.logger.add_metadata(:user_id => @current_user.id)
end

MongodbLogger: querying via the Rails console

>> db = Rails.logger.mongo_connection
>> collection = db[Rails.logger.mongo_collection_name]

Find all requests for a specific user (with id):

>> cursor = collection.find(:user_id => '12355')
>> cursor.count
=> 5

Find all requests that took more that one second to complete:

>> collection.find({:runtime => {'$gt' => 1000}}).count
=> 3

MongodbLogger: querying via the Rails console

Find all requests with an exception that contains "RoutingError":

>> collection.find({"messages.error" => /RoutingError/})

Find all requests with errors:

>> collection.find({"is_exception" => true})

Find all requests by params in request

>> collection.find({"params.activity" => {'$exists' => true}})

MongodbLogger: Restrictions

• The database doesn't allow update the existing objects in the collection (for logging this is plus!);
• The database doesn't allow deleting objects from a capped collection (for logging this is plus!);
• Capped collection are not shardable;
• More indexes - slower inserts (common case for all databases :));