debian-mirror-gitlab/lib/gitlab/tracing/jaeger_factory.rb
2019-03-02 22:35:43 +05:30

97 lines
3 KiB
Ruby

# frozen_string_literal: true
require 'jaeger/client'
module Gitlab
module Tracing
class JaegerFactory
# When the probabilistic sampler is used, by default 0.1% of requests will be traced
DEFAULT_PROBABILISTIC_RATE = 0.001
# The default port for the Jaeger agent UDP listener
DEFAULT_UDP_PORT = 6831
# Reduce this from default of 10 seconds as the Ruby jaeger
# client doesn't have overflow control, leading to very large
# messages which fail to send over UDP (max packet = 64k)
# Flush more often, with smaller packets
FLUSH_INTERVAL = 5
def self.create_tracer(service_name, options)
kwargs = {
service_name: service_name,
sampler: get_sampler(options[:sampler], options[:sampler_param]),
reporter: get_reporter(service_name, options[:http_endpoint], options[:udp_endpoint])
}.compact
extra_params = options.except(:sampler, :sampler_param, :http_endpoint, :udp_endpoint, :strict_parsing, :debug) # rubocop: disable CodeReuse/ActiveRecord
if extra_params.present?
message = "jaeger tracer: invalid option: #{extra_params.keys.join(", ")}"
if options[:strict_parsing]
raise message
else
warn message
end
end
Jaeger::Client.build(kwargs)
end
def self.get_sampler(sampler_type, sampler_param)
case sampler_type
when "probabilistic"
sampler_rate = sampler_param ? sampler_param.to_f : DEFAULT_PROBABILISTIC_RATE
Jaeger::Samplers::Probabilistic.new(rate: sampler_rate)
when "const"
const_value = sampler_param == "1"
Jaeger::Samplers::Const.new(const_value)
else
nil
end
end
private_class_method :get_sampler
def self.get_reporter(service_name, http_endpoint, udp_endpoint)
encoder = Jaeger::Encoders::ThriftEncoder.new(service_name: service_name)
if http_endpoint.present?
sender = get_http_sender(encoder, http_endpoint)
elsif udp_endpoint.present?
sender = get_udp_sender(encoder, udp_endpoint)
else
return nil
end
Jaeger::Reporters::RemoteReporter.new(
sender: sender,
flush_interval: FLUSH_INTERVAL
)
end
private_class_method :get_reporter
def self.get_http_sender(encoder, address)
Jaeger::HttpSender.new(
url: address,
encoder: encoder,
logger: Logger.new(STDOUT)
)
end
private_class_method :get_http_sender
def self.get_udp_sender(encoder, address)
pair = address.split(":", 2)
host = pair[0]
port = pair[1] ? pair[1].to_i : DEFAULT_UDP_PORT
Jaeger::UdpSender.new(
host: host,
port: port,
encoder: encoder,
logger: Logger.new(STDOUT)
)
end
private_class_method :get_udp_sender
end
end
end