Class: Scaltainer::ServiceTypeBase

Inherits:
Object
  • Object
show all
Defined in:
lib/scaltainer/service_types/base.rb

Direct Known Subclasses

ServiceTypeWeb, ServiceTypeWorker

Instance Method Summary collapse

Constructor Details

#initialize(app_endpoint) ⇒ ServiceTypeBase

Returns a new instance of ServiceTypeBase.



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# File 'lib/scaltainer/service_types/base.rb', line 3

def initialize(app_endpoint)
  @app_endpoint = app_endpoint.sub('$HIREFIRE_TOKEN', ENV['HIREFIRE_TOKEN'] || '') if app_endpoint
end

Instance Method Details

#adjust_desired_replicas(desired_replicas, config) ⇒ Object 



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# File 'lib/scaltainer/service_types/base.rb', line 17

def adjust_desired_replicas(desired_replicas, config)
  desired_replicas = [config["max"], desired_replicas].min if config["max"]
  [config["min"], desired_replicas].max
end

#determine_desired_replicas(metric, service_config, current_replicas) ⇒ Object 



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# File 'lib/scaltainer/service_types/base.rb', line 12

def determine_desired_replicas(metric, service_config, current_replicas)
  raise ConfigurationError.new 'No metric found for requested service' unless metric
  raise ConfigurationError.new 'No configuration found for requested service' unless service_config
end

#get_metrics(services) ⇒ Object 



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# File 'lib/scaltainer/service_types/base.rb', line 7

def get_metrics(services)
  services_count = services.keys.length rescue 0
  raise Scaltainer::Warning.new "No services found for #{self.class.name}" if services_count == 0
end

#to_s ⇒ Object 



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# File 'lib/scaltainer/service_types/base.rb', line 62

def to_s
  "Base"
end

#yield_to_scale(replica_diff, config, state, metric, service_name, logger) ⇒ Object 



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# File 'lib/scaltainer/service_types/base.rb', line 22

def yield_to_scale(replica_diff, config, state, metric, service_name, logger)
  # Force up/down when below/above min/max?
  # one could argue that this could only happen on first deployment or when manually
  # scaled outside the scope of scaltainer. It is OK in this case to still apply sensitivity rules
  if replica_diff > 0
    # breach: change state and scale up
    state["upscale_sensitivity"] ||= 0
    state["upscale_sensitivity"] += 1
    state["downscale_sensitivity"] = 0
    if state["upscale_sensitivity"] >= config["upscale_sensitivity"]
      yield
      state["upscale_sensitivity"] = 0
    else
      logger.debug "Scaling up of service #{service_name} blocked by upscale_sensitivity at level " +
        "#{state["upscale_sensitivity"]} while level #{config["upscale_sensitivity"]} is required"
    end
  elsif replica_diff < 0  # TODO force down when above max?
    # breach: change state and scale down
    if can_scale_down? metric, config
      state["downscale_sensitivity"] ||= 0
      state["downscale_sensitivity"] += 1
      state["upscale_sensitivity"] = 0
      if state["downscale_sensitivity"] >= config["downscale_sensitivity"]
        yield
        state["downscale_sensitivity"] = 0
      else
        logger.debug "Scaling down of service #{service_name} blocked by downscale_sensitivity at level " +
          "#{state["downscale_sensitivity"]} while level #{config["downscale_sensitivity"]} is required"
      end
    else
      logger.debug "Scaling down of service #{service_name} to #{metric} replicas blocked by a non-decrementable config"
    end
  else
    # no breach, change state
    state["upscale_sensitivity"] = 0
    state["downscale_sensitivity"] = 0
    logger.info "No need to scale service #{service_name}"
  end
end