What Bloom filter is?
Bloom filter can be understood as a very precise set configuration, when you use it contains a method of determining whether the object exists, it may be false. However, Bloom filter is not particularly precise, as long as a reasonable set of parameters, it is sufficiently precise relative accuracy can be controlled, there will only be a small probability of false positives
Bloom filter using substantially
Bloom filter has two basic instruction, bf.add add elements, bf.exists query element is present, if you want to add more, you need to use bf.madd instruction. Likewise if you need a query whether there is more than one element, you need to use bf.mexists instruction.
127.0.0.1:6379> bf.add codehole user1
(integer) 1
127.0.0.1:6379> bf.add codehole user2
(integer) 1
127.0.0.1:6379> bf.add codehole user3
(integer) 1
127.0.0.1:6379> bf.exists codehole user1
(integer) 1
127.0.0.1:6379> bf.exists codehole user2
(integer) 1
127.0.0.1:6379> bf.exists codehole user3
(integer) 1
127.0.0.1:6379> bf.exists codehole user4
(integer) 0
127.0.0.1:6379> bf.madd codehole user4 user5 user6
1) (integer) 1
2) (integer) 1
3) (integer) 1
127.0.0.1:6379> bf.mexists codehole user4 user5 user6 user7
1) (integer) 1
2) (integer) 1
3) (integer) 1
4) (integer) 0