net.spy.memcached
Class KetamaNodeLocator

java.lang.Object
  net.spy.memcached.compat.SpyObject
      net.spy.memcached.KetamaNodeLocator

All Implemented Interfaces:

NodeLocator

public final class KetamaNodeLocator
extends SpyObject
implements NodeLocator

This is an implementation of the Ketama consistent hash strategy from last.fm. This implementation may not be compatible with libketama as hashing is considered separate from node location. Note that this implementation does not currently supported weighted nodes.

See Also:

RJ's blog post

Constructor Summary

KetamaNodeLocator(List<MemcachedNode> nodes, HashAlgorithm alg)

KetamaNodeLocator(List<MemcachedNode> nodes, HashAlgorithm alg, KetamaNodeLocatorConfiguration conf)

Method Summary

Collection<MemcachedNode>	getAll() Get all memcached nodes.
MemcachedNode	getPrimary(String k) Get the primary location for the given key.
NodeLocator	getReadonlyCopy() Create a read-only copy of this NodeLocator.
Iterator<MemcachedNode>	getSequence(String k) Get an iterator over the sequence of nodes that make up the backup locations for a given key.

Methods inherited from class net.spy.memcached.compat.SpyObject

getLogger

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

KetamaNodeLocator

public KetamaNodeLocator(List<MemcachedNode> nodes,
                         HashAlgorithm alg)

KetamaNodeLocator

public KetamaNodeLocator(List<MemcachedNode> nodes,
                         HashAlgorithm alg,
                         KetamaNodeLocatorConfiguration conf)

Method Detail

getAll

public Collection<MemcachedNode> getAll()

Description copied from interface: NodeLocator

Get all memcached nodes. This is useful for broadcasting messages.

Specified by:

getAll in interface NodeLocator

getPrimary

public MemcachedNode getPrimary(String k)

Description copied from interface: NodeLocator

Get the primary location for the given key.

Specified by:

getPrimary in interface NodeLocator

Parameters:

k - the object key

Returns:

the QueueAttachment containing the primary storage for a key

getSequence

public Iterator<MemcachedNode> getSequence(String k)

Description copied from interface: NodeLocator

Get an iterator over the sequence of nodes that make up the backup locations for a given key.

Specified by:

getSequence in interface NodeLocator

Parameters:

k - the object key

Returns:

the sequence of backup nodes.

getReadonlyCopy

public NodeLocator getReadonlyCopy()

Description copied from interface: NodeLocator

Create a read-only copy of this NodeLocator.

Specified by:

getReadonlyCopy in interface NodeLocator