CHash

A lightweight library for load distribution.

Description

Combines modular hashing and consistent hashing. The algorithm distributes partitions between nodes using consistent hashing, then uses modular hashing to determine partition for key (and thus the node for key).

The algorithm limits the load on a node, which makes distribution more or less even as you can see in the table below.

Nodes	Next	Median Partitions	Min Partitions	Max Partitions	Partitions Moved
16	17	753	704	754	6.49%
17	18	708	674	709	6.42%
18	19	669	625	670	5.69%
19	20	634	595	635	5.53%
20	21	602	556	603	5.53%
...	...	...	...	...	...
66	67	182	164	183	2.22%
67	68	180	159	181	2.30%
68	69	177	159	178	2.38%
69	70	174	161	175	2.37%
70	71	172	154	173	2.05%