Class: LogStash::Outputs::AmazonES

Inherits:

Base

• Object
• Base
• LogStash::Outputs::AmazonES

Includes:

Stud::Buffer

Defined in:

lib/logstash/outputs/amazon_es.rb

Overview

This output plugin emits data to Amazon Elasticsearch with support for signing requests using AWS V4 Signatures

The configuration and experience is similar to logstash-output-elasticsearch plugin and we have added Signature V4 support for the same Some of the default configurations like connection timeouts have been tuned for optimal performance with Amazon Elasticsearch

Retry Policy

This plugin uses the same retry policy as logstash-output-elasticsearch, It uses bulk API to optimize its imports into Elasticsearch.. These requests may experience either partial or total failures. Events are retried if they fail due to either a network error or the status codes 429 (the server is busy), 409 (Version Conflict), or 503 (temporary overloading/maintenance).

The retry policy’s logic can be described as follows:

• Block and retry all events in the bulk response that experience transient network exceptions until a successful submission is received by Elasticsearch.

• Retry the subset of sent events which resulted in ES errors of a retryable nature.

• Events which returned retryable error codes will be pushed onto a separate queue for retrying events. Events in this queue will be retried a maximum of 5 times by default (configurable through :max_retries). The size of this queue is capped by the value set in :retry_max_items.

• Events from the retry queue are submitted again when the queue reaches its max size or when the max interval time is reached. The max interval time is configurable via :retry_max_interval.

• Events which are not retryable or have reached their max retry count are logged to stderr.

Constant Summary

RETRYABLE_CODES =

[409, 429, 503]

SUCCESS_CODES =

[200, 201]

Instance Attribute Summary

• #client ⇒ Object readonly

  Returns the value of attribute client.

Instance Method Summary

• #flush(actions, teardown = false) ⇒ Object
• #get_template ⇒ Object
• #receive(event) ⇒ Object
• #register ⇒ Object
• #submit(actions) ⇒ Object

  The submit method can be called from both the Stud::Buffer flush thread and from our own retry thread.

• #teardown ⇒ Object

Instance Attribute Details

#client ⇒ Object (readonly)

Returns the value of attribute client.

# File 'lib/logstash/outputs/amazon_es.rb', line 39

def client
  @client
end

Instance Method Details

#flush(actions, teardown = false) ⇒ Object

# File 'lib/logstash/outputs/amazon_es.rb', line 349

def flush(actions, teardown = false)
  begin
    submit(actions)
  rescue Manticore::SocketException => e
    # If we can't even connect to the server let's just print out the URL (:hosts is actually a URL)
    # and let the user sort it out from there
    @logger.error(
      "Attempted to send a bulk request to Elasticsearch configured at '#{@client.client_options[:hosts]}',"+
        " but Elasticsearch appears to be unreachable or down!",
      :client_config => @client.client_options,
      :error_message => e.message
    )
    @logger.debug("Failed actions for last bad bulk request!", :actions => actions)
  rescue => e
    # For all other errors print out full connection issues
    @logger.error(
      "Attempted to send a bulk request to Elasticsearch configured at '#{@client.client_options[:hosts]}'," +
          " but an error occurred and it failed! Are you sure you can reach elasticsearch from this machine using " +
        "the configuration provided?",
      :client_config => @client.client_options,
      :error_message => e.message,
      :error_class => e.class.name,
      :backtrace => e.backtrace
    )

    @logger.debug("Failed actions for last bad bulk request!", :actions => actions)

    raise e
  end
end

#get_template ⇒ Object

# File 'lib/logstash/outputs/amazon_es.rb', line 267

def get_template
  if @template.nil?
    @template = ::File.expand_path('amazon_es/elasticsearch-template.json', ::File.dirname(__FILE__))
    if !File.exists?(@template)
      raise "You must specify 'template => ...' in your elasticsearch output (I looked for '#{@template}')"
    end
  end
  template_json = IO.read(@template).gsub(/\n/,'')
  template = LogStash::Json.load(template_json)
  @logger.info("Using mapping template", :template => template)
  return template
end

#receive(event) ⇒ Object

# File 'lib/logstash/outputs/amazon_es.rb', line 281

def receive(event)
  return unless output?(event)

  # block until we have not maxed out our
  # retry queue. This is applying back-pressure
  # to slow down the receive-rate
  @retry_flush_mutex.synchronize {
    @retry_queue_not_full.wait(@retry_flush_mutex) while @retry_queue.size > @retry_max_items
  }

  event.set('[@metadata][retry_count]', 0)

  # Set the 'type' value for the index.
  type = if @document_type
           event.sprintf(@document_type)
         elsif @index_type # deprecated
           event.sprintf(@index_type)
         else
           event.get('type') || 'logs'
         end

  params = {
    :_id => @document_id ? event.sprintf(@document_id) : nil,
    :_index => event.sprintf(@index),
    :_type => type,
    :_routing => @routing ? event.sprintf(@routing) : nil
  }

  params[:_upsert] = LogStash::Json.load(event.sprintf(@upsert)) if @action == 'update' && @upsert != ""

  buffer_receive([event.sprintf(@action), params, event])
end

#register ⇒ Object

# File 'lib/logstash/outputs/amazon_es.rb', line 194

def register
  @hosts = Array(@hosts)
  # retry-specific variables
  @retry_flush_mutex = Mutex.new
  @retry_teardown_requested = Concurrent::AtomicBoolean.new(false)
  # needs flushing when interval
  @retry_queue_needs_flushing = ConditionVariable.new
  @retry_queue_not_full = ConditionVariable.new
  @retry_queue = Queue.new
  @submit_mutex = Mutex.new

  client_settings = {}
  common_options = {
    :client_settings => client_settings
  }

  client_settings[:path] = "/#{@path}/".gsub(/\/+/, "/") # Normalize slashes
  @logger.debug? && @logger.debug("Normalizing http path", :path => @path, :normalized => client_settings[:path])

  if @hosts.nil? || @hosts.empty?
    @logger.info("No 'host' set in elasticsearch output. Defaulting to localhost")
    @hosts = ["localhost"]
  end

  client_settings.merge! setup_proxy()
  common_options.merge! setup_basic_auth()

  # Update API setup
  update_options = {
    :upsert => @upsert,
    :doc_as_upsert => @doc_as_upsert
  }
  common_options.merge! update_options if @action == 'update'

  @client = LogStash::Outputs::AES::HttpClient.new(
    common_options.merge(:hosts => @hosts, :port => @port, :region => @region, :aws_access_key_id => @aws_access_key_id, :aws_secret_access_key => @aws_secret_access_key,:protocol => @protocol)
  )

  if @manage_template
    begin
      @logger.info("Automatic template management enabled", :manage_template => @manage_template.to_s)
      @client.template_install(@template_name, get_template, @template_overwrite)
    rescue => e
      @logger.error("Failed to install template: #{e.message}")
    end
  end

  @logger.info("New Elasticsearch output", :hosts => @hosts, :port => @port)

  @client_idx = 0

  buffer_initialize(
    :max_items => @flush_size,
    :max_interval => @idle_flush_time,
    :logger => @logger
  )

  @retry_timer_thread = Thread.new do
    loop do
      sleep(@retry_max_interval)
      @retry_flush_mutex.synchronize { @retry_queue_needs_flushing.signal }
    end
  end

  @retry_thread = Thread.new do
    while @retry_teardown_requested.false?
      @retry_flush_mutex.synchronize { @retry_queue_needs_flushing.wait(@retry_flush_mutex) }
      retry_flush
    end
  end
end

#submit(actions) ⇒ Object

The submit method can be called from both the Stud::Buffer flush thread and from our own retry thread.

# File 'lib/logstash/outputs/amazon_es.rb', line 317

def submit(actions)
  @submit_mutex.synchronize do
    es_actions = actions.map { |a, doc, event| [a, doc, event.to_hash] }

    bulk_response = @client.bulk(es_actions)

    if bulk_response["errors"] && bulk_response["items"]
      actions_to_retry = []

      bulk_response['items'].each_with_index do |item,idx|
        action = es_actions[idx]
        action_type, props = item.first # These are all hashes with one value, so we destructure them here

        status = props['status']
        error = props['error']

        if RETRYABLE_CODES.include?(status)
          @logger.warn "retrying failed action with response code: #{status}"
          actions_to_retry << action
        elsif not SUCCESS_CODES.include?(status)
          @logger.warn "failed action", status: status, error: error, action: action
        end
      end

      retry_push(actions_to_retry) unless actions_to_retry.empty?
    end
  end
end

#teardown ⇒ Object

# File 'lib/logstash/outputs/amazon_es.rb', line 381

def teardown

  @retry_teardown_requested.make_true
  # First, make sure retry_timer_thread is stopped
  # to ensure we do not signal a retry based on
  # the retry interval.
  Thread.kill(@retry_timer_thread)
  @retry_timer_thread.join
  # Signal flushing in the case that #retry_flush is in
  # the process of waiting for a signal.
  @retry_flush_mutex.synchronize { @retry_queue_needs_flushing.signal }
  # Now, #retry_flush is ensured to not be in a state of
  # waiting and can be safely joined into the main thread
  # for further final execution of an in-process remaining call.
  @retry_thread.join

  # execute any final actions along with a proceeding retry for any
  # final actions that did not succeed.
  buffer_flush(:final => true)
  retry_flush
end