A generic implementation of the Consistent Hashing algorithm using an AVL tree.
- set number of replicas to create multiple virtual points in the ring for each node
- nodes can be arbitrary data (e.g. a Memcache client instance)
- fast performance through using an AVL tree internally
require 'consistent_hashing' ring = ConsistentHashing::Ring.new ring << "192.168.1.101" << "192.168.1.102" ring.node_for("foobar") # => 192.168.1.101 ring.delete("192.168.1.101") # after removing 192.168.1.101, all keys previously mapped to it move clockwise to # the next node ring.node_for("foobar") # => 192.168.1.102 ring.nodes # => ["192.168.1.101", "192.168.1.102"] ring.points # => [#<ConsistentHashing::VirtualPoint>, #<ConsistentHashing::VirtualPoint>, ...]
For large amounts of nodes, avoid using the
<< method. Use
add instead to add the nodes to the ring. The reason for
this is, that each call to
<< returns a reference to the complete ring, which can get quite big.
[sudo] gem install consistent-hashing
Original author: Dominik Liebler firstname.lastname@example.org
(The MIT License)
Copyright (c) 2013 Dominik Liebler
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