Class MemCache::Server
In: lib/memcache.rb  (CVS)
Parent: Object

A Multiton datatype to represent a potential memcached server connection.

Methods

alive?   inspect   mark_dead   new   socket  

Constants

ConnectTimeout = 0.25   Default timeout for connections to memcached servers.

Attributes

connect_timeout  [RW]  The number of (floating-point) seconds before a connection fails.
host  [R]  The host the memcached server is running on
port  [R]  The port the memcached is listening on
retry  [R]  The Time of next connection retry if the object is dead.
status  [R]  A text status string describing the state of the server.
weight  [R]  The weight given to the server

Public Class methods

new( host, port=11211, weight=DefaultServerWeight, timeout=ConnectTimeout )

Create a new MemCache::Server object for the memcached instance listening on the given host and port, weighted with the given weight.

[Source]

# File lib/memcache.rb, line 1184
        def initialize( host, port=11211, weight=DefaultServerWeight, timeout=ConnectTimeout )
            if host.nil? || host.empty?
                raise ArgumentError, "Illegal host %p" % host
            elsif port.nil? || port.to_i.zero?
                raise ArgumentError, "Illegal port %p" % port
            end

            @host     = host
            @port     = port
            @weight   = weight

            @connect_timeout = timeout

            @sock     = nil
            @retry    = nil
            @status   = "not yet connected"
        end

Public Instance methods

alive?()

Test the server for aliveness, returning true if the object was able to connect. This will cause the socket connection to be opened if it isn’t already.

[Source]

# File lib/memcache.rb, line 1240
        def alive?
            return !self.socket.nil?
        end
inspect()

Return a string representation of the server object.

[Source]

# File lib/memcache.rb, line 1227
        def inspect
            return "<MemCache::Server: %s:%d [%d] (%s)>" % [
                @host,
                @port,
                @weight,
                @status,
            ]
        end
mark_dead( reason="Unknown error" )

Mark the server as dead for 30 seconds and close its socket. The specified reason will be used to construct an appropriate status message.

[Source]

# File lib/memcache.rb, line 1278
        def mark_dead( reason="Unknown error" )
            @sock.close if @sock && !@sock.closed?
            @sock = nil
            @retry = Time::now + ( 30 + rand(10) )
            @status = "DEAD: %s: Will retry at %s" %
                [ reason, @retry ]
        end
socket()

Try to connect to the memcached targeted by this object. Returns the connected socket object on success; sets @dead and returns nil on any failure.

[Source]

# File lib/memcache.rb, line 1248
        def socket

            # Connect if not already connected
            unless @sock || (!@sock.nil? && @sock.closed?)

                # If the host was dead, don't retry for a while
                if @retry
                    return nil if @retry > Time::now
                end

                # Attempt to connect, 
                begin
                    @sock = timeout( @connect_timeout ) {
                        TCPSocket::new( @host, @port )
                    }
                    @status = "connected"
                rescue SystemCallError, IOError, TimeoutError => err
                    # $deferr.puts "Error while connecting to %s:%d: %s" %
                    #  [ @host, @port, err.message ]
                    self.mark_dead( err.message )
                end
            end

            return @sock
        end

[Validate]