Class: Connection

Inherits:
Object
  • Object
show all
Defined in:
lib/connection/connection.rb

Direct Known Subclasses

TCPConnection

Constant Summary collapse

STATUS_OK = 
"ok"
PROTOCOL = 
"pb0"
DEFAULT_REQUEST_LIMIT_PER_NODE = 
500

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(db_name, hosts, request_limit_per_node = DEFAULT_REQUEST_LIMIT_PER_NODE) ⇒ Connection

Returns a new instance of Connection.



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# File 'lib/connection/connection.rb', line 20

def initialize(db_name, hosts, request_limit_per_node = DEFAULT_REQUEST_LIMIT_PER_NODE)
  self.db_name = db_name
  self.hosts   = hosts
  self.nodes   = hosts.collect{ |h|
                  n = h.split(":")
                  node = VoldemortNode.new
                  node.host = n[0]
                  node.port = n[1]
                  node
                 }
  self.request_count = 0
  self.request_limit_per_node = request_limit_per_node
end

Instance Attribute Details

#connected_node ⇒ Object

The VoldemortNode we are connected to.



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# File 'lib/connection/connection.rb', line 8

def connected_node
  @connected_node
end

#db_name ⇒ Object

The DB store name.



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# File 'lib/connection/connection.rb', line 7

def db_name
  @db_name
end

#hosts ⇒ Object

The hosts from where we bootstrapped.



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# File 'lib/connection/connection.rb', line 5

def hosts
  @hosts
end

#key_serializer_schemas ⇒ Object

Returns the value of attribute key_serializer_schemas.



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# File 'lib/connection/connection.rb', line 11

def key_serializer_schemas
  @key_serializer_schemas
end

#key_serializer_type ⇒ Object

Returns the value of attribute key_serializer_type.



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# File 'lib/connection/connection.rb', line 13

def key_serializer_type
  @key_serializer_type
end

#nodes ⇒ Object

The array of VoldemortNodes available.



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# File 'lib/connection/connection.rb', line 6

def nodes
  @nodes
end

#request_count ⇒ Object

Used to track the number of request a node receives.



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# File 'lib/connection/connection.rb', line 9

def request_count
  @request_count
end

#request_limit_per_node ⇒ Object

Limit the number of request per node.



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# File 'lib/connection/connection.rb', line 10

def request_limit_per_node
  @request_limit_per_node
end

#value_serializer_schemas ⇒ Object

Returns the value of attribute value_serializer_schemas.



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# File 'lib/connection/connection.rb', line 12

def value_serializer_schemas
  @value_serializer_schemas
end

#value_serializer_type ⇒ Object

Returns the value of attribute value_serializer_type.



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# File 'lib/connection/connection.rb', line 14

def value_serializer_type
  @value_serializer_type
end

Instance Method Details

#bootstrap ⇒ Object 



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# File 'lib/connection/connection.rb', line 34

def bootstrap
  cluster_response = self.get_from("metadata", "cluster.xml", false)
  cluster_xml_doc = Nokogiri::XML(cluster_response[1][0][1])
  self.nodes = self.parse_nodes_from(cluster_xml_doc)

  stores_response = self.get_from("metadata", "stores.xml", false)

  stores_xml = stores_response[1][0][1]

  doc = Nokogiri::XML(stores_xml)

  self.key_serializer_type = self.parse_schema_type(doc, 'key-serializer')
  self.value_serializer_type = self.parse_schema_type(doc, 'value-serializer')
  self.key_serializer_schemas = self.parse_schema_from(doc, 'key-serializer')
  self.value_serializer_schemas = self.parse_schema_from(doc, 'value-serializer')

  self.connect_to_random_node

rescue StandardError => e
   raise("There was an error trying to bootstrap from the specified servers: #{e}")
end

#connect ⇒ Object 



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# File 'lib/connection/connection.rb', line 103

def connect
  self.connect!
end

#connect_to_random_node ⇒ Object 



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# File 'lib/connection/connection.rb', line 56

def connect_to_random_node
  nodes = self.nodes.sort_by { rand }
  for node in nodes do
    if self.connect_to(node.host, node.port)
      self.connected_node = node
      self.request_count = 0
      return node
    end
  end
end

#delete(key) ⇒ Object 



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# File 'lib/connection/connection.rb', line 144

def delete(key)
  self.delete_from(self.db_name, key)
end

#disconnect ⇒ Object 



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# File 'lib/connection/connection.rb', line 111

def disconnect
  self.disconnect!
end

#get(key) ⇒ Object 



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# File 'lib/connection/connection.rb', line 129

def get(key)
  self.rebalance_connection_if_needed
  self.get_from(self.db_name, key, false)
end

#get_all(keys) ⇒ Object 



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# File 'lib/connection/connection.rb', line 134

def get_all(keys)
  self.rebalance_connection_if_needed
  self.get_all_from(self.db_name, keys, false)
end

#parse_nodes_from(doc) ⇒ Object 



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# File 'lib/connection/connection.rb', line 84

def parse_nodes_from(doc)
  nodes = []
  doc.xpath("/cluster/server").each do |n|
    node = VoldemortNode.new      
    node.id = n.xpath("id").text
    node.host = n.xpath("host").text
    node.port = n.xpath("socket-port").text
    node.http_port = n.xpath("http_port").text
    node.admin_port = n.xpath("admin-port").text
    node.partitions = n.xpath("partitions").text
    nodes << node
  end
  nodes
end

#parse_schema_from(doc, serializer = 'value-serializer') ⇒ Object 



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# File 'lib/connection/connection.rb', line 76

def parse_schema_from(doc, serializer = 'value-serializer')
  parsed_schemas = {}
  doc.xpath("//stores/store[name = \"#{self.db_name}\"]/#{serializer}/schema-info").each do |value_serializer|
    parsed_schemas[value_serializer.attributes['version'].text] = value_serializer.text
  end
  return parsed_schemas
end

#parse_schema_type(doc, serializer = 'value-serializer') ⇒ Object 



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# File 'lib/connection/connection.rb', line 67

def parse_schema_type(doc, serializer = 'value-serializer')
  type_doc = doc.xpath("//stores/store[name = \"#{self.db_name}\"]/#{serializer}/type")
  if(type_doc != nil)
    return type_doc.text
  else
    return nil
  end
end

#protocol_version ⇒ Object 



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# File 'lib/connection/connection.rb', line 99

def protocol_version
  PROTOCOL
end

#put(key, value, version = nil, route = false) ⇒ Object 



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# File 'lib/connection/connection.rb', line 139

def put(key, value, version = nil, route = false)
  self.rebalance_connection_if_needed
  self.put_from(self.db_name, key, value, version, route)
end

#rebalance_connection? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/connection/connection.rb', line 120

def rebalance_connection?
  self.request_count >= self.request_limit_per_node
end

#rebalance_connection_if_needed ⇒ Object 



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# File 'lib/connection/connection.rb', line 124

def rebalance_connection_if_needed
  self.reconnect if self.rebalance_connection?
  self.request_count += 1
end

#reconnect ⇒ Object 



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# File 'lib/connection/connection.rb', line 107

def reconnect
  self.reconnect!
end

#reconnect_when_errors_in(response = nil) ⇒ Object 



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# File 'lib/connection/connection.rb', line 115

def reconnect_when_errors_in(response = nil)
  return unless response
  self.reconnect! if response.error
end