Spymemcached Hanging after Operations Completed

Question

I am using Spymemcached to access Memcached on a server. I started memcached using the following command

memcached -m 4096 -p 11211 -u memcache -l 127.0.0.1 -d -vvv

and I am using the following driver to put some key/value pairs into Memcache. For some reason, after the last get operation, the main function just hangs; it never terminates.

import java.net.InetSocketAddress;
import net.spy.memcached.MemcachedClient;

public class memcache {
        public static void main(String args[]) {
                //Connect to Memcache.
                MemcachedClient c=null;
                try{   
                        c = new MemcachedClient(
                                new InetSocketAddress("127.0.0.1", 11211));
                } catch (Exception e) {
                        System.err.println("Could not connect to Memcached.");
                        System.exit(-1);
                }
                System.out.println("Connected to Memcached.");
                Object myObject = null;
                for (int i = 0; i < 10; i++)
                {
                        c.set(new String("HELLO"), 3600, i+1);
                        myObject=c.get("HELLO");
                        String value = myObject.toString();
                        System.out.println("***" + value);
                }
                System.out.println("Done.");
                return;
        }
}

I get the following output, but the application never terminates.

2011-12-04 14:18:31.839 INFO net.spy.memcached.MemcachedConnection:  Added {QA sa=/127.0.0.1:11211, #Rops=0, #Wops=0, #iq=0, topRop=null, topWop=null, toWrite=0, interested=0} to connect queue
Connected to Memcached.
2011-12-04 14:18:31.844 INFO net.spy.memcached.MemcachedConnection:  Connection state changed for sun.nio.ch.SelectionKeyImpl@578088c0
***1
Done.

The server is reporting the following status:

<32 server listening (udp)
<33 new auto-negotiating client connection
33: going from conn_new_cmd to conn_waiting
33: going from conn_waiting to conn_read
33: going from conn_read to conn_parse_cmd
33: Client using the ascii protocol
<33 set HELLO 512 3600 1
33: going from conn_parse_cmd to conn_nread
> NOT FOUND HELLO
>33 STORED
33: going from conn_nread to conn_write
33: going from conn_write to conn_new_cmd
33: going from conn_new_cmd to conn_waiting
33: going from conn_waiting to conn_read
33: going from conn_read to conn_parse_cmd
<33 get HELLO
> FOUND KEY HELLO
>33 sending key HELLO
>33 END
33: going from conn_parse_cmd to conn_mwrite
33: going from conn_mwrite to conn_new_cmd
33: going from conn_new_cmd to conn_waiting
33: going from conn_waiting to conn_read

What problem might be causing the main function to never terminate? Does anyone have any suggestions?

Answer 1

The solution was easy. The client must disconnect when it is done:

c.shutdown(...)

None of the examples include this critical step.