soloestoy / rebloom

Bloom Filter Datatype for Redis

ReBloom - Bloom Filter Module for Redis

This module provides a scalable bloom filter as a Redis data type. Bloom filters are probabilistic data structures that do a very good job of quickly determining if something is contained within a set.

Building

In order to use this module, build it using make and load it into Redis.

Using

Invoking redis with the module loaded

$ redis-server --loadmodule /path/to/rebloom.so

Adding items to filter

127.0.0.1:6379> BF.MADD bf foo bar baz
1) (integer) 1
2) (integer) 1
3) (integer) 1

Checking if items exist

127.0.0.1:6379> BF.MEXISTS bf foo nonexist 3
1) (integer) 1
2) (integer) 0
3) (integer) 0

You can find a command reference in docs/Commands.md

Module Options

You can adjust the default error ratio and the initial filter size using the ERROR_RATE and INITIAL_SIZE options respectively when loading the module, e.g.:

$ redis-server --loadmodule /path/to/rebloom.so INITIAL_SIZE 400 ERROR_RATE 0.004

The default error rate is 0.01 and the default initial capacity is 100.