Class: Scaltainer::ServiceTypeWeb

Inherits:
ServiceTypeBase show all
Defined in:
lib/scaltainer/service_types/web.rb

Instance Method Summary collapse

Methods inherited from ServiceTypeBase

#adjust_desired_replicas, #yield_to_scale

Constructor Details

#initialize(app_endpoint = nil) ⇒ ServiceTypeWeb

Returns a new instance of ServiceTypeWeb.



3
4
5
 
# File 'lib/scaltainer/service_types/web.rb', line 3

def initialize(app_endpoint = nil)
  super
end

Instance Method Details

#determine_desired_replicas(metric, service_config, current_replicas) ⇒ Object 



29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
 
# File 'lib/scaltainer/service_types/web.rb', line 29

def determine_desired_replicas(metric, service_config, current_replicas)
  super
  raise ConfigurationError.new "Missing max_response_time in web service configuration" unless service_config["max_response_time"]
  raise ConfigurationError.new "Missing min_response_time in web service configuration" unless service_config["min_response_time"]
  unless service_config["min_response_time"] <= service_config["max_response_time"]
    raise ConfigurationError.new "min_response_time and max_response_time are not in order"
  end
  desired_replicas = if metric > service_config["max_response_time"]
    current_replicas + service_config["upscale_quantity"]
  elsif metric < service_config["min_response_time"]
    current_replicas - service_config["downscale_quantity"]
  else
    current_replicas
  end
end

#get_metrics(services) ⇒ Object 



7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
 
# File 'lib/scaltainer/service_types/web.rb', line 7

def get_metrics(services)
  super
  nr_key = ENV['NEW_RELIC_API_KEY']
  raise ConfigurationError.new 'NEW_RELIC_API_KEY not set in environment' unless nr_key
  nr = Newrelic::Metrics.new nr_key
  to = Time.now
  from = to - (ENV['RESPONSE_TIME_WINDOW'] || '5').to_i * 60

  services.reduce({}) do |hash, (service_name, service_config)|
    app_id = service_config["newrelic_app_id"]
    raise ConfigurationError.new "Service #{service_name} does not have a corresponding newrelic_app_id" unless app_id

    begin
      metric = nr.get_avg_response_time app_id, from, to
    rescue => e
      raise NetworkError.new "Could not retrieve metrics from New Relic API for #{service_name}: #{e.message}"
    end

    hash.merge!(service_name => metric)
  end
end

#to_s ⇒ Object 



45
46
47
 
# File 'lib/scaltainer/service_types/web.rb', line 45

def to_s
  "Web"
end