Class: PrometheusExporter::Instrumentation::ActiveRecord

Inherits:
PeriodicStats
  • Object
show all
Defined in:
lib/prometheus_exporter/instrumentation/active_record.rb

Constant Summary collapse

ALLOWED_CONFIG_LABELS = 
%i[database username host port]

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from PeriodicStats

started?, stop, worker_loop

Constructor Details

#initialize(metric_labels, config_labels) ⇒ ActiveRecord

Returns a new instance of ActiveRecord.



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# File 'lib/prometheus_exporter/instrumentation/active_record.rb', line 39

def initialize(metric_labels, config_labels)
  @metric_labels = metric_labels
  @config_labels = config_labels
end

Class Method Details

.start(client: nil, frequency: 30, custom_labels: {}, config_labels: []) ⇒ Object 



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# File 'lib/prometheus_exporter/instrumentation/active_record.rb', line 8

def self.start(client: nil, frequency: 30, custom_labels: {}, config_labels: [])
  client ||= PrometheusExporter::Client.default

  # Not all rails versions support connection pool stats
  unless ::ActiveRecord::Base.connection_pool.respond_to?(:stat)
    client.logger.error(
      "ActiveRecord connection pool stats not supported in your rails version",
    )
    return
  end

  config_labels.map!(&:to_sym)
  validate_config_labels(config_labels)

  active_record_collector = new(custom_labels, config_labels)

  worker_loop do
    metrics = active_record_collector.collect
    metrics.each { |metric| client.send_json metric }
  end

  super
end

.validate_config_labels(config_labels) ⇒ Object 



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# File 'lib/prometheus_exporter/instrumentation/active_record.rb', line 32

def self.validate_config_labels(config_labels)
  return if config_labels.size == 0
  if (config_labels - ALLOWED_CONFIG_LABELS).size > 0
    raise "Invalid Config Labels, available options #{ALLOWED_CONFIG_LABELS}"
  end
end

Instance Method Details

#collect ⇒ Object 



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# File 'lib/prometheus_exporter/instrumentation/active_record.rb', line 44

def collect
  metrics = []
  collect_active_record_pool_stats(metrics)
  metrics
end

#collect_active_record_pool_stats(metrics) ⇒ Object 



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# File 'lib/prometheus_exporter/instrumentation/active_record.rb', line 54

def collect_active_record_pool_stats(metrics)
  ObjectSpace.each_object(::ActiveRecord::ConnectionAdapters::ConnectionPool) do |pool|
    next if pool.connections.nil?

    metric = {
      pid: pid,
      type: "active_record",
      hostname: ::PrometheusExporter.hostname,
      metric_labels: labels(pool),
    }
    metric.merge!(pool.stat)
    metrics << metric
  end
end

#pid ⇒ Object 



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# File 'lib/prometheus_exporter/instrumentation/active_record.rb', line 50

def pid
  @pid = ::Process.pid
end