Class: RightAws::AWSErrorHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/awsbase/right_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



1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
 
# File 'lib/awsbase/right_awsbase.rb', line 1015

def initialize(aws, parser, params={}) #:nodoc:     
  @aws           = aws              # Link to RightEc2 | RightSqs | RightS3 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 



1003
1004
1005
 
# File 'lib/awsbase/right_awsbase.rb', line 1003

def self.close_on_4xx_probability 
  @@close_on_4xx_probability 
end

.close_on_4xx_probability=(close_on_4xx_probability) ⇒ Object 



1006
1007
1008
 
# File 'lib/awsbase/right_awsbase.rb', line 1006

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

.close_on_error ⇒ Object 



995
996
997
 
# File 'lib/awsbase/right_awsbase.rb', line 995

def self.close_on_error 
  @@close_on_error 
end

.close_on_error=(close_on_error) ⇒ Object 



998
999
1000
 
# File 'lib/awsbase/right_awsbase.rb', line 998

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

.reiteration_start_delay ⇒ Object 



979
980
981
 
# File 'lib/awsbase/right_awsbase.rb', line 979

def self.reiteration_start_delay
  @@reiteration_start_delay
end

.reiteration_start_delay=(reiteration_start_delay) ⇒ Object 



982
983
984
 
# File 'lib/awsbase/right_awsbase.rb', line 982

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

.reiteration_time ⇒ Object 



987
988
989
 
# File 'lib/awsbase/right_awsbase.rb', line 987

def self.reiteration_time
  @@reiteration_time
end

.reiteration_time=(reiteration_time) ⇒ Object 



990
991
992
 
# File 'lib/awsbase/right_awsbase.rb', line 990

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

Instance Method Details

#check(request) ⇒ Object

Returns false if



1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
 
# File 'lib/awsbase/right_awsbase.rb', line 1029

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[:protocol]}://#{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

  # Extract error/redirection message from the response body
  # Amazon claims that a redirection must have a body but somethimes it is nil....
  if response.body && response.body[/^(<\?xml|<ErrorResponse)/]
    error_parser = RightErrorResponseParser.new
    @aws.class.bench_xml.add! do
      error_parser.parse(response.body)
    end
    @aws.last_errors     = error_parser.errors
    @aws.last_request_id = error_parser.requestID
    last_errors_text     = @aws.last_errors.flatten.join("\n")
  else
    @aws.last_errors     = [[response.code, "#{response.message} (#{request_text_data})"]]
    @aws.last_request_id = '-undefined-'
    last_errors_text     = response.message
  end
  
  # Ok, it is a redirect, find the new destination location
  if redirect_detected
    location = response['location']
    # As for 301 ( Moved Permanently) Amazon does not return a 'Location' header but
    # it is possible to extract a new endpoint from the response body
    if location.right_blank? && response.code=='301' && response.body
      new_endpoint = response.body[/<Endpoint>(.*?)<\/Endpoint>/] && $1
      location     = "#{request[:protocol]}://#{new_endpoint}:#{request[:port]}#{request[:request].path}"
    end
    # ... log information and ...
    @aws.logger.info("##### #{@aws.class.name} redirect requested: #{response.code} #{response.message} #####")
    @aws.logger.info("      Old location: #{request_text_data}")
    @aws.logger.info("      New location: #{location}")
    @aws.logger.info("      Request Verb: #{request[:request].class.name}")
    # ... fix the connection data
    request[:server]   = URI.parse(location).host
    request[:protocol] = URI.parse(location).scheme
    request[:port]     = URI.parse(location).port
  else
    # Not a redirect but an error: try to find the error in our list
    @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.destroy_connection(request, "#{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

      else
        @aws.logger.info("##### Retry ##{@retries} is being performed due to a redirect.  ####")
      end

      # 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

      result = @aws.request_info(request, @parser)
    else
      @aws.logger.warn("##### Ooops, time is over... ####")
    end 
  # aha, this is unhandled error: 
  elsif @close_on_error 
    # On 5xx(Server errors), 403(RequestTimeTooSkewed) and 408(Request Timeout) a conection has to be closed
    if @aws.last_response.code.to_s[/^(5\d\d|403|408)$/]
      @aws.destroy_connection(request, "#{self.class.name}: code: #{@aws.last_response.code}: '#{@aws.last_response.message}'")
    # Is this a 4xx error ? 
    elsif @aws.last_response.code.to_s[/^4\d\d$/] && @close_on_4xx_probability > rand(100) 
      @aws.destroy_connection(request, "#{self.class.name}: code: #{@aws.last_response.code}: '#{@aws.last_response.message}', " +
                                       "probability: #{@close_on_4xx_probability}%")
    end
  end
  result
end