+##
+# This class represents a redis server instance.
+
+class Server
+
+ ##
+ # The amount of time to wait before attempting to re-establish a
+ # connection with a server that is marked dead.
+
+ RETRY_DELAY = 30.0
+
+ ##
+ # The host the redis server is running on.
+
+ attr_reader :host
+
+ ##
+ # The port the redis server is listening on.
+
+ attr_reader :port
+
+ ##
+ #
+
+ attr_reader :replica
+
+ ##
+ # The time of next retry if the connection is dead.
+
+ attr_reader :retry
+
+ ##
+ # A text status string describing the state of the server.
+
+ attr_reader :status
+
+ ##
+ # Create a new Redis::Server object for the redis instance
+ # listening on the given host and port.
+
+ def initialize(host, port = DEFAULT_PORT)
+ raise ArgumentError, "No host specified" if host.nil? or host.empty?
+ raise ArgumentError, "No port specified" if port.nil? or port.to_i.zero?
+
+ @host = host
+ @port = port.to_i
+
+ @sock = nil
+ @retry = nil
+ @status = 'NOT CONNECTED'
+ @timeout = 1
+ end
+
+ ##
+ # Return a string representation of the server object.
+ def inspect
+ "<Redis::Server: %s:%d (%s)>" % [@host, @port, @status]
+ end
+
+ ##
+ # Try to connect to the redis server targeted by this object.
+ # Returns the connected socket object on success or nil on failure.
+
+ def socket
+ return @sock if @sock and not @sock.closed?
+
+ @sock = nil
+
+ # If the host was dead, don't retry for a while.
+ return if @retry and @retry > Time.now
+
+ # Attempt to connect if not already connected.
+ begin
+ @sock = connect_to(@host, @port, @timeout)
+ @sock.setsockopt Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1
+ @retry = nil
+ @status = 'CONNECTED'
+ rescue Errno::EPIPE, Errno::ECONNREFUSED => e
+ puts "Socket died... socket: #{@sock.inspect}\n" if $debug
+ @sock.close
+ retry
+ rescue SocketError, SystemCallError, IOError => err
+ puts "Unable to open socket: #{err.class.name}, #{err.message}" if $debug
+ mark_dead err
+ end
+
+ return @sock
+ end
+
+ def connect_to(host, port, timeout=nil)
+ addrs = Socket.getaddrinfo('localhost', nil)
+ addr = addrs.detect { |ad| ad[0] == 'AF_INET' }
+ sock = Socket.new(Socket::AF_INET, Socket::SOCK_STREAM, 0)
+ #addr = Socket.getaddrinfo(host, nil)
+ #sock = Socket.new(Socket.const_get(addr[0][0]), Socket::SOCK_STREAM, 0)
+
+ if timeout
+ secs = Integer(timeout)
+ usecs = Integer((timeout - secs) * 1_000_000)
+ optval = [secs, usecs].pack("l_2")
+ sock.setsockopt Socket::SOL_SOCKET, Socket::SO_RCVTIMEO, optval
+ sock.setsockopt Socket::SOL_SOCKET, Socket::SO_SNDTIMEO, optval
+ end
+ sock.connect(Socket.pack_sockaddr_in('6379', addr[3]))
+ sock
+ end
+
+ ##
+ # Close the connection to the redis server targeted by this
+ # object. The server is not considered dead.
+
+ def close
+ @sock.close if @sock && !@sock.closed?
+ @sock = nil
+ @retry = nil
+ @status = "NOT CONNECTED"
+ end
+
+ ##
+ # Mark the server as dead and close its socket.
+ def mark_dead(error)
+ @sock.close if @sock && !@sock.closed?
+ @sock = nil
+ @retry = Time.now #+ RETRY_DELAY
+
+ reason = "#{error.class.name}: #{error.message}"
+ @status = sprintf "%s:%s DEAD (%s), will retry at %s", @host, @port, reason, @retry
+ puts @status
+ end
+
+end
projects / redis.git / commitdiff
