log4r-azure

Ruby gem for Log4r that uses Windows Azure Table Storage as an Outputter.

You must already have an Azure storage account created. Once you've nominated the account to use, log4r-azure will use a table called "logging" by default.

The Partition Key will be set to "Logging", for example if we're logging for March 2014, you'd see a partition key of "LoggingMar2014".

Due to the way Azure charges for transactions, you can save money by batching your records together. If you set batch to be a high value (more than 100?), you may notice a delay in your logging. so think about what you can accept for a time / money trade off and set this value carefully. Azure maintains a "CreatedAt" attribute with a timestamp, however this will be the time that the batch is sent to the server - not the time the event actually happened. To determine that, use the RowKey instead. Log4r-azure will create records with the RowKey as a Unix timestamp (seconds since epoch). RowKeys are stored as strings in Azure Table Storage, not timestamps, so unfortunately it's still a bit annoying to retrieve, however if you download your logs you can convert the RowKey to a proper timestamp.

Make sure you're using log4r already, then add it to your Gemfile:

gem 'log4r-azure'

You need to feed log4r-azure your storage account and access key. If you're using Rails, you can create an initializer such as config/initializers/azure_logging.rb

require 'azure_logging'

Azure.configure do |config|
  config.storage_account_name = "YourAccountName"
  config.storage_access_key = "<put your key here>"
end

You can omit the "Azure.configure" block if you set the environment variables instead:

AZURE_STORAGE_ACCOUNT = <your azure storage account name>
AZURE_STORAGE_ACCESS_KEY = <your azure storage access key>

You just need to add the AzureOutputter into your logging configuration, just like any other Outputter. For example, to log to a text file, console and Azure:

log4r_config:
  # define all loggers ...
  loggers:
    - name      : development
      level     : ALL
      trace     : 'true'
      outputters :
      - file
      - azure
      - console
  outputters:
  - type: StdoutOutputter
    name: console
    formatter:
      date_pattern: '%H:%M:%S'
      pattern     : '%d %l: %m '
      type        : PatternFormatter
  - type: FileOutputter
    name: file
    filename: "log/development.log" # notice the file extension is needed! 
    formatter:
      date_pattern: '%H:%M:%S'
      pattern     : '%d %l: %m '
      type        : PatternFormatter
  - type: AzureOutputter
    name: azure
    batch: 5
    formatter:
      date_pattern: '%H:%M:%S'
      pattern     : '%d %l: %m '
      type        : PatternFormatter

This gem does not attempt to solve this problem! There isn't a way to view the data from the Azure console yet, but I've been using Visual Studio 2013 as a client, and that works pretty well. I think there are a few clients on codeplex and the like. Please contact me if you find some good ones - I'll list them here.

I hope this gem is useful to someone! Timothy.