performance.txt @@ -1,3 +1,9 @@ += 1.7.1 + +* Performance optimization. Rely on higher performance operating system socket timeouts for + low-level socket read/writes where possible, instead of the (slower) SystemTimer or (slowest, + unreliable) Timeout libraries. + = 1.7.0 (2009-03-08) * Go through the memcached protocol document and implement any commands not already implemented: History.rdoc @@ -33,7 +33,7 @@ class MemCache ## # The version of MemCache you are using. - VERSION = '1.7.0' + VERSION = '1.7.1' ## # Default options for the cache object. @@ -822,7 +822,7 @@ class MemCache block.call(socket) - rescue SocketError, Timeout::Error => err + rescue SocketError, Errno::EAGAIN, Timeout::Error => err logger.warn { "Socket failure: #{err.message}" } if logger server.mark_dead(err) handle_error(server, err) @@ -922,13 +922,6 @@ class MemCache class Server ## - # The amount of time to wait to establish a connection with a memcached - # server. If a connection cannot be established within this time limit, - # the server will be marked as down. - - CONNECT_TIMEOUT = 0.25 - - ## # The amount of time to wait before attempting to re-establish a # connection with a server that is marked dead. @@ -1011,14 +1004,11 @@ class MemCache # Attempt to connect if not already connected. begin - @sock = @timeout ? TCPTimeoutSocket.new(@host, @port, @timeout) : TCPSocket.new(@host, @port) - - if Socket.constants.include? 'TCP_NODELAY' then - @sock.setsockopt Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1 - end + @sock = connect_to(@host, @port, @timeout) + @sock.setsockopt Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1 @retry = nil @status = 'CONNECTED' - rescue SocketError, SystemCallError, IOError, Timeout::Error => err + rescue SocketError, SystemCallError, IOError => err logger.warn { "Unable to open socket: #{err.class.name}, #{err.message}" } if logger mark_dead err end @@ -1026,6 +1016,33 @@ class MemCache return @sock end + def connect_to(host, port, timeout=nil) + 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 + + # Socket timeouts don't work for more complex IO operations + # like gets which lay on top of read. We need to fall back to + # the standard Timeout mechanism. + sock.instance_eval <<-EOR + alias :blocking_gets :gets + def gets + MemCacheTimer.timeout(#{timeout}) do + self.blocking_gets + end + end + EOR + end + sock.connect(Socket.pack_sockaddr_in(port, addr[0][3])) + sock + end + ## # Close the connection to the memcached server targeted by this # object. The server is not considered dead. @@ -1059,51 +1076,6 @@ class MemCache end -# TCPSocket facade class which implements timeouts. -class TCPTimeoutSocket - - def initialize(host, port, timeout) - MemCacheTimer.timeout(MemCache::Server::CONNECT_TIMEOUT) do - @sock = TCPSocket.new(host, port) - @len = timeout - end - end - - def write(*args) - MemCacheTimer.timeout(@len) do - @sock.write(*args) - end - end - - def gets(*args) - MemCacheTimer.timeout(@len) do - @sock.gets(*args) - end - end - - def read(*args) - MemCacheTimer.timeout(@len) do - @sock.read(*args) - end - end - - def _socket - @sock - end - - def method_missing(meth, *args) - @sock.__send__(meth, *args) - end - - def closed? - @sock.closed? - end - - def close - @sock.close - end -end - module Continuum POINTS_PER_SERVER = 160 # this is the default in libmemcached lib/memcache.rb @@ -1,5 +1,5 @@ HERE = File.dirname(__FILE__) -$LOAD_PATH << "#{HERE}/../lib/" +$LOAD_PATH.unshift "#{HERE}/../lib" #$LOAD_PATH << "/Library/Ruby/Gems/1.8/gems/activesupport-2.2.2/lib/active_support/vendor/memcache-client-1.5.1" require 'benchmark' test/test_benchmark.rb cd4b9982e20b1003e81112e3234128dc4db3b11a Mike Perham mperham@gmail.com http://github.com/mperham/memcache-client/commit/9f5201b77ccb6ef0d021e741cab8468151f2535d 9f5201b77ccb6ef0d021e741cab8468151f2535d 2009-03-15T18:39:11-07:00 2009-03-15T18:39:11-07:00 Optimization: use raw socket timeouts where possible. 7539e489ad83b87bb8d212f15956bdd513fc0856 Mike Perham mperham@gmail.com