Class: MemCache::Server
- Inherits:
-
Object
- Object
- MemCache::Server
- Defined in:
- lib/memcache.rb
Overview
This class represents a memcached server instance.
Constant Summary collapse
- RETRY_DELAY =
The amount of time to wait before attempting to re-establish a connection with a server that is marked dead.
30.0
Instance Attribute Summary collapse
-
#host ⇒ Object
readonly
The host the memcached server is running on.
-
#logger ⇒ Object
readonly
Returns the value of attribute logger.
-
#port ⇒ Object
readonly
The port the memcached server is listening on.
-
#retry ⇒ Object
readonly
The time of next retry if the connection is dead.
-
#status ⇒ Object
readonly
A text status string describing the state of the server.
-
#weight ⇒ Object
readonly
The weight given to the server.
Instance Method Summary collapse
-
#alive? ⇒ Boolean
Check whether the server connection is alive.
-
#close ⇒ Object
Close the connection to the memcached server targeted by this object.
- #connect_to(host, port, timeout = nil) ⇒ Object
-
#initialize(memcache, host, port = DEFAULT_PORT, weight = DEFAULT_WEIGHT) ⇒ Server
constructor
Create a new MemCache::Server object for the memcached instance listening on the given host and port, weighted by the given weight.
-
#inspect ⇒ Object
Return a string representation of the server object.
-
#mark_dead(error) ⇒ Object
Mark the server as dead and close its socket.
-
#socket ⇒ Object
Try to connect to the memcached server targeted by this object.
Constructor Details
#initialize(memcache, host, port = DEFAULT_PORT, weight = DEFAULT_WEIGHT) ⇒ Server
Create a new MemCache::Server object for the memcached instance listening on the given host and port, weighted by the given weight.
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# File 'lib/memcache.rb', line 994 def initialize(memcache, host, port = DEFAULT_PORT, weight = DEFAULT_WEIGHT) 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 @weight = weight.to_i @sock = nil @retry = nil @status = 'NOT CONNECTED' @timeout = memcache.timeout @logger = memcache.logger end |
Instance Attribute Details
#host ⇒ Object (readonly)
The host the memcached server is running on.
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# File 'lib/memcache.rb', line 966 def host @host end |
#logger ⇒ Object (readonly)
Returns the value of attribute logger.
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# File 'lib/memcache.rb', line 988 def logger @logger end |
#port ⇒ Object (readonly)
The port the memcached server is listening on.
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# File 'lib/memcache.rb', line 971 def port @port end |
#retry ⇒ Object (readonly)
The time of next retry if the connection is dead.
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# File 'lib/memcache.rb', line 981 def retry @retry end |
#status ⇒ Object (readonly)
A text status string describing the state of the server.
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# File 'lib/memcache.rb', line 986 def status @status end |
#weight ⇒ Object (readonly)
The weight given to the server.
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# File 'lib/memcache.rb', line 976 def weight @weight end |
Instance Method Details
#alive? ⇒ Boolean
Check whether the server connection is alive. This will cause the socket to attempt to connect if it isn’t already connected and or if the server was previously marked as down and the retry time has been exceeded.
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# File 'lib/memcache.rb', line 1022 def alive? !!socket end |
#close ⇒ Object
Close the connection to the memcached server targeted by this object. The server is not considered dead.
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# File 'lib/memcache.rb', line 1086 def close @sock.close if @sock && !@sock.closed? @sock = nil @retry = nil @status = "NOT CONNECTED" end |
#connect_to(host, port, timeout = nil) ⇒ Object
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# File 'lib/memcache.rb', line 1052 def connect_to(host, port, timeout=nil) sock = nil if timeout MemCacheTimer.timeout(timeout) do sock = TCPSocket.new(host, port) end else sock = TCPSocket.new(host, port) end io = MemCache::BufferedIO.new(sock) io.read_timeout = timeout # Getting reports from several customers, including 37signals, # that the non-blocking timeouts in 1.7.5 don't seem to be reliable. # It can't hurt to set the underlying socket timeout also, if possible. if timeout secs = Integer(timeout) usecs = Integer((timeout - secs) * 1_000_000) optval = [secs, usecs].pack("l_2") begin io.setsockopt Socket::SOL_SOCKET, Socket::SO_RCVTIMEO, optval io.setsockopt Socket::SOL_SOCKET, Socket::SO_SNDTIMEO, optval rescue Exception => ex # Solaris, for one, does not like/support socket timeouts. @logger.info "[memcache-client] Unable to use raw socket timeouts: #{ex.class.name}: #{ex.}" if @logger end end io end |
#inspect ⇒ Object
Return a string representation of the server object.
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# File 'lib/memcache.rb', line 1012 def inspect "<MemCache::Server: %s:%d [%d] (%s)>" % [@host, @port, @weight, @status] end |
#mark_dead(error) ⇒ Object
Mark the server as dead and close its socket.
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# File 'lib/memcache.rb', line 1096 def mark_dead(error) @sock.close if @sock && !@sock.closed? @sock = nil @retry = Time.now + RETRY_DELAY reason = "#{error.class.name}: #{error.}" @status = sprintf "%s:%s DEAD (%s), will retry at %s", @host, @port, reason, @retry @logger.info { @status } if @logger end |
#socket ⇒ Object
Try to connect to the memcached server targeted by this object. Returns the connected socket object on success or nil on failure.
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# File 'lib/memcache.rb', line 1030 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 SocketError, SystemCallError, IOError, Timeout::Error => err logger.warn { "Unable to open socket: #{err.class.name}, #{err.}" } if logger mark_dead err end return @sock end |