class LogStash::Outputs::Graphite
This output allows you to pull metrics from your logs and ship them to Graphite
. Graphite
is an open source tool for storing and graphing metrics.
An example use case: Some applications emit aggregated stats in the logs every 10 seconds. Using the grok filter and this output, it is possible to capture the metric values from the logs and emit them to Graphite
.
Constants
- DEFAULT_METRICS_FORMAT
- EXCLUDE_ALWAYS
- METRIC_PLACEHOLDER
Public Instance Methods
connect()
click to toggle source
# File lib/logstash/outputs/graphite.rb, line 92 def connect # TODO(sissel): Test error cases. Catch exceptions. Find fortune and glory. Retire to yak farm. begin @socket = TCPSocket.new(@host, @port) rescue Errno::ECONNREFUSED => e @logger.warn("Connection refused to graphite server, sleeping...", :host => @host, :port => @port) sleep(@reconnect_interval) retry end end
construct_metric_name(event, metric)
click to toggle source
# File lib/logstash/outputs/graphite.rb, line 103 def construct_metric_name(event, metric) if @metrics_format sprinted = event.sprintf(@metrics_format) return sprinted.gsub(METRIC_PLACEHOLDER, metric) end metric end
receive(event)
click to toggle source
# File lib/logstash/outputs/graphite.rb, line 112 def receive(event) # Graphite message format: metric value timestamp\n # compact to remove nil messages which produces useless \n messages = ( @fields_are_metrics \ ? messages_from_event_fields(event, @include_metrics, @exclude_metrics) : messages_from_event_metrics(event, @metrics) ).compact if messages.empty? @logger.debug? && @logger.debug("Message is empty, not sending anything to Graphite", :messages => messages, :host => @host, :port => @port) else message = messages.join("\n") @logger.debug? && @logger.debug("Sending carbon messages", :messages => messages, :host => @host, :port => @port) # Catch exceptions like ECONNRESET and friends, reconnect on failure. # TODO(sissel): Test error cases. Catch exceptions. Find fortune and glory. begin @socket.puts(message) rescue Errno::EPIPE, Errno::ECONNRESET, IOError => e @logger.warn("Connection to graphite server died", :exception => e.class, :message => e.message, :host => @host, :port => @port) sleep(@reconnect_interval) connect retry if @resend_on_failure rescue => e @logger.warn("Failed to send data", :exception => e.class, :message => e.message, :host => @host, :port => @port) sleep(@reconnect_interval) connect retry if @resend_on_failure end end end
register()
click to toggle source
# File lib/logstash/outputs/graphite.rb, line 79 def register @include_metrics.collect!{|regexp| Regexp.new(regexp)} @exclude_metrics.collect!{|regexp| Regexp.new(regexp)} if @metrics_format && !@metrics_format.include?(METRIC_PLACEHOLDER) @logger.warn("metrics_format does not include placeholder #{METRIC_PLACEHOLDER} .. falling back to default format: #{DEFAULT_METRICS_FORMAT.inspect}") @metrics_format = DEFAULT_METRICS_FORMAT end connect end
Private Instance Methods
dotify(hash, prefix = nil)
click to toggle source
Take a nested ruby hash of the form {:a => {:b => 2}, c: => 3} and turn it into a hash of the form { “a.b” => 2, “c” => 3}
# File lib/logstash/outputs/graphite.rb, line 195 def dotify(hash, prefix = nil) hash.reduce({}) do |acc, kv| k, v = kv pk = prefix ? "#{prefix}#{@nested_object_separator}#{k}" : k.to_s if v.is_a?(Hash) acc.merge!(dotify(v, pk)) elsif v.is_a?(Array) # There's no right answer here, so we do nothing @logger.warn("Array values not supported for graphite metrics! Ignoring #{hash} @ #{prefix}") else acc[pk] = v end acc end end
event_timestamp(event)
click to toggle source
# File lib/logstash/outputs/graphite.rb, line 174 def event_timestamp(event) event.get(@timestamp_field).to_i end
messages_from_event_fields(event, include_metrics, exclude_metrics)
click to toggle source
# File lib/logstash/outputs/graphite.rb, line 148 def messages_from_event_fields(event, include_metrics, exclude_metrics) @logger.debug? && @logger.debug("got metrics event", :metrics => event.to_hash) timestamp = event_timestamp(event) event.to_hash.flat_map do |metric,value| next if EXCLUDE_ALWAYS.include?(metric) next unless include_metrics.empty? || include_metrics.any? { |regexp| metric.match(regexp) } next if exclude_metrics.any? {|regexp| metric.match(regexp)} metrics_lines_for_event(event, metric, value, timestamp) end end
messages_from_event_metrics(event, metrics)
click to toggle source
# File lib/logstash/outputs/graphite.rb, line 161 def messages_from_event_metrics(event, metrics) timestamp = event_timestamp(event) metrics.flat_map do |metric, value| @logger.debug? && @logger.debug("processing", :metric => metric, :value => value) metric = event.sprintf(metric) next unless @include_metrics.any? {|regexp| metric.match(regexp)} next if @exclude_metrics.any? {|regexp| metric.match(regexp)} metrics_lines_for_event(event, metric, value, timestamp) end end
metrics_line(event, name, value, timestamp)
click to toggle source
# File lib/logstash/outputs/graphite.rb, line 188 def metrics_line(event, name, value, timestamp) "#{construct_metric_name(event, name)} #{value} #{timestamp}" end
metrics_lines_for_event(event, metric, value, timestamp)
click to toggle source
# File lib/logstash/outputs/graphite.rb, line 178 def metrics_lines_for_event(event, metric, value, timestamp) if event.get(metric).is_a?(Hash) dotify(event.get(metric), metric).map do |k, v| metrics_line(event, k, v, timestamp) end else metrics_line(event, event.sprintf(metric), event.sprintf(value).to_f, timestamp) end end