Class: Aws::AWSErrorHandler

Inherits:
Object show all
Defined in:
lib/awsbase/awsbase.rb

Constant Summary collapse

DEFAULT_CLOSE_ON_4XX_PROBABILITY =

0-100 (%)

10
@@reiteration_start_delay = 
0.2
@@reiteration_time = 
5
@@close_on_error = 
true
@@close_on_4xx_probability = 
DEFAULT_CLOSE_ON_4XX_PROBABILITY

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(aws, parser, params = {}) ⇒ AWSErrorHandler

params:

:reiteration_time
:errors_list
:close_on_error           = true | false
:close_on_4xx_probability = 1-100



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# File 'lib/awsbase/awsbase.rb', line 481

def initialize(aws, parser, params={}) #:nodoc:
  @aws           = aws              # Link to Ec2 | Sqs | S3 instance
  @parser        = parser           # parser to parse Amazon response
  @started_at    = Time.now
  @stop_at       = @started_at  + (params[:reiteration_time] || @@reiteration_time)
  @errors_list   = params[:errors_list] || []
  @reiteration_delay = @@reiteration_start_delay
  @retries       = 0
  # close current HTTP(S) connection on 5xx, errors from list and 4xx errors
  @close_on_error           = params[:close_on_error].nil? ? @@close_on_error : params[:close_on_error]
  @close_on_4xx_probability = params[:close_on_4xx_probability] || @@close_on_4xx_probability
end

Class Method Details

.close_on_4xx_probability ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 469

def self.close_on_4xx_probability
  @@close_on_4xx_probability
end

.close_on_4xx_probability=(close_on_4xx_probability) ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 472

def self.close_on_4xx_probability=(close_on_4xx_probability)
  @@close_on_4xx_probability = close_on_4xx_probability
end

.close_on_error ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 461

def self.close_on_error
  @@close_on_error
end

.close_on_error=(close_on_error) ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 464

def self.close_on_error=(close_on_error)
  @@close_on_error = close_on_error
end

.reiteration_start_delay ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 445

def self.reiteration_start_delay
  @@reiteration_start_delay
end

.reiteration_start_delay=(reiteration_start_delay) ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 448

def self.reiteration_start_delay=(reiteration_start_delay)
  @@reiteration_start_delay = reiteration_start_delay
end

.reiteration_time ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 453

def self.reiteration_time
  @@reiteration_time
end

.reiteration_time=(reiteration_time) ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 456

def self.reiteration_time=(reiteration_time)
  @@reiteration_time = reiteration_time
end

Instance Method Details

#check(request) ⇒ Object

Returns false if



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# File 'lib/awsbase/awsbase.rb', line 495

def check(request)  #:nodoc:
  result           = false
  error_found      = false
  redirect_detected= false
  error_match      = nil
  last_errors_text = ''
  response         = @aws.last_response
  # log error
  request_text_data = "#{request[:server]}:#{request[:port]}#{request[:request].path}"
  # is this a redirect?
  # yes!
  if response.is_a?(Net::HTTPRedirection)
    redirect_detected = true
  else
    # no, it's an error ...
    @aws.logger.warn("##### #{@aws.class.name} returned an error: #{response.code} #{response.message}\n#{response.body} #####")
    @aws.logger.warn("##### #{@aws.class.name} request: #{request_text_data} ####")
  end
  # Check response body: if it is an Amazon XML document or not:
  if redirect_detected || (response.body && response.body[/<\?xml/])   # ... it is a xml document
    @aws.class.bench_xml.add! do
      error_parser = ErrorResponseParser.new
      error_parser.parse(response)
      @aws.last_errors     = error_parser.errors
      @aws.last_request_id = error_parser.requestID
      last_errors_text     = @aws.last_errors.flatten.join("\n")
      # on redirect :
      if redirect_detected
        location = response['location']
        # ... log information and ...
        @aws.logger.info("##### #{@aws.class.name} redirect requested: #{response.code} #{response.message} #####")
        @aws.logger.info("##### New location: #{location} #####")
        # ... fix the connection data
        request[:server]   = URI.parse(location).host
        request[:protocol] = URI.parse(location).scheme
        request[:port]     = URI.parse(location).port
      end
    end
  else                               # ... it is not a xml document(probably just a html page?)
    @aws.last_errors     = [[response.code, "#{response.message} (#{request_text_data})"]]
    @aws.last_request_id = '-undefined-'
    last_errors_text     = response.message
  end
  # now - check the error
  unless redirect_detected
    @errors_list.each do |error_to_find|
      if last_errors_text[/#{error_to_find}/i]
        error_found = true
        error_match = error_to_find
        @aws.logger.warn("##### Retry is needed, error pattern match: #{error_to_find} #####")
        break
      end
    end
  end
  # check the time has gone from the first error come
  if redirect_detected || error_found
    # Close the connection to the server and recreate a new one.
    # It may have a chance that one server is a semi-down and reconnection
    # will help us to connect to the other server
    if !redirect_detected && @close_on_error
      @aws.connection.finish "#{self.class.name}: error match to pattern '#{error_match}'"
    end

    if (Time.now < @stop_at)
      @retries += 1
      unless redirect_detected
        @aws.logger.warn("##### Retry ##{@retries} is being performed. Sleeping for #{@reiteration_delay} sec. Whole time: #{Time.now-@started_at} sec ####")
        sleep @reiteration_delay
        @reiteration_delay *= 2

        # Always make sure that the fp is set to point to the beginning(?)
        # of the File/IO. TODO: it assumes that offset is 0, which is bad.
        if(request[:request].body_stream && request[:request].body_stream.respond_to?(:pos))
          begin
            request[:request].body_stream.pos = 0
          rescue Exception => e
            @logger.warn("Retry may fail due to unable to reset the file pointer" +
                         " -- #{self.class.name} : #{e.inspect}")
          end
        end
      else
        @aws.logger.info("##### Retry ##{@retries} is being performed due to a redirect.  ####")
      end
      result = @aws.request_info(request, @parser)
    else
      @aws.logger.warn("##### Ooops, time is over... ####")
    end
    # aha, this is unhandled error:
  elsif @close_on_error
    # Is this a 5xx error ?
    if @aws.last_response.code.to_s[/^5\d\d$/]
      @aws.connection.finish "#{self.class.name}: code: #{@aws.last_response.code}: '#{@aws.last_response.message}'"
      # Is this a 4xx error ?
    elsif @aws.last_response.code.to_s[/^4\d\d$/] && @close_on_4xx_probability > rand(100)
      @aws.connection.finish "#{self.class.name}: code: #{@aws.last_response.code}: '#{@aws.last_response.message}', " +
        "probability: #{@close_on_4xx_probability}%"
    end
  end
  result
end