Class: RubyZipkin::RackHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/rubyzipkin.rb

Instance Method Summary collapse

Constructor Details

#initialize(app, service_name, scribe_server, scribe_port, uri_filter_list = [], http_header_filter_list = [], uri_sample_filter_list = {}, sampling_rate = 0.0001, scribe_max_buffer = 50, redis_config = 'config/redis.yml') ⇒ RackHandler

Returns a new instance of RackHandler.



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# File 'lib/rubyzipkin.rb', line 18

def initialize(app, service_name, scribe_server, scribe_port, uri_filter_list = [], http_header_filter_list = [], uri_sample_filter_list = {}, sampling_rate = 0.0001, scribe_max_buffer = 50, redis_config = 'config/redis.yml')
  @app = app
  @lock = Mutex.new

  @service_name = service_name
  @scribe_port = scribe_port
  @sample_rate = sampling_rate
  @uri_filter_list = uri_filter_list
  @http_header_filter_list = http_header_filter_list
  @uri_sample_filter_list = uri_sample_filter_list
  @scribe = Scribe.new("#{scribe_server}:#{scribe_port}")
  @redis_config = redis_config
  @sampled_ids = []
  $redis_check_time = Time.now
  ::Trace.tracer = ::Trace::ZipkinTracer.new(Scriber.new(@scribe), scribe_max_buffer)

  begin
    @redis = redis_from_config(redis_config) if File.exists?(@redis_config)
  rescue => e
    $stderr.puts "No Redis instance"
  end
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/rubyzipkin.rb', line 50

def call(env)
  begin
    ::Trace.default_endpoint = ::Trace.default_endpoint.with_service_name(@service_name + "/#{top_level_path(env['PATH_INFO'])}")
    set_sample_rate(env)
    trace_id = get_or_create_trace_id(env)
    env[ZipkinTraceHeader::PARENT_SPAN_ID] = @spanid
    env[ZipkinTraceHeader::TRACE_ID] = @tid

  rescue => e
    $stderr.puts "ZIPKIN [ERR] #{e}"
  end

  begin
    @status, @headers, @response = @app.call(env)
    redis_sampling
    tracing_filter(trace_id, env, @headers)
  rescue => e
    # we want to do the call even if zipkin fails
    $stderr.puts "ZIPKIN [ERR] #{e} \n\n\n #{e.backtrace}"
  end
  [@status, @headers, @response]
end

#redis_from_config(file_name) ⇒ Object 



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# File 'lib/rubyzipkin.rb', line 41

def redis_from_config(file_name)
  config = YAML.load_file(file_name)['production']
  if config && (host = config['host']) && (port = config['port'])
    instance = Redis.new(:host => host, :port => port, :logger => Rails.logger, :thread_safe => true)
    instance.select(config['db']) if config['db']
    instance
  end
end