PmcMiller

PmcMiller provides an interface to read and analyze data gathered by (Puppet Metrics Collector)[https://github.com/puppetlabs/puppetlabs-puppet_metrics_collector].

Installation

Add this line to your application's Gemfile:

gem "pmc_miller"

And then execute:

$ bundle

Or install it yourself as:

$ gem install pmc_miller

Usage

Reader

The PmcMiller::Reader class can be used to accumulate service data for a given key. This provides a ruby object based approach to grepping metrics.

The following code snippet initializes the reader object to a specified puppet-metrics-collector path and then accumulates the data for queue_depth associated with the puppetdb service.

require "pmc_miller/reader"

reader = PmcMiller::Reader.new("/path/to/puppet-metrics-collector")
reader.service = "puppetdb"
data = reader.read("queue_depth")

The data object returned is an array of PmcMiller::DataPoint objects. These objects are a struct consisting of the Time and value of the data point for the key that was used for the lookup. From our previous example, the Data object would appear as follows.

puts data    # produces:

#<struct PmcMiller::DataPoint time_string="1970-01-01T00:00:01Z", value=0>
#<struct PmcMiller::DataPoint time_string="1971-01-01T00:00:01Z", value=10>
#<struct PmcMiller::DataPoint time_string="1972-01-01T00:00:01Z", value=20>

Analyzer

PmcMiller contains analyzer classes. These consume a Data object and return an object that contains the following methods.

summary : String of the summary of the analysis (pass/fail).

results : Hash of calculations created to feed the analysis.

settings : Hash of configuration settings used to influence the analysis.

to_json : JSON string of the previous three methods.

require "pmc_miller/reader"

reader = PmcMiller::Reader.new("/path/to/puppet-metrics-collector")
reader.service = "puppetdb"

data = reader.read("queue_depth")

qd = PmcMiller::PuppetDB::QueueDepth.new(data)

json = qd.to_json

puts json    #=> {"results":{"rate_of_change":3153600.0},"settings":{},"summary":"fail"}

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/puppetlabs/pmc_miller.