Now we understand the definition of consistent hashing, let us find out how it works. Assume SHA-1 is used as the hash function f, and the output range of the hash function is: x0, x1, x2, x3, …, xn. In cryptography, SHA-1’s hash space goes from 0 to 2^160 - 1. That means x0 corresponds to 0, xn corresponds to 2^160 – 1, and all the other hash values in the middle fall between 0 and 2^160 - 1. Figure 3 shows the hash space.

Figure 3

Figure 3

By collecting both ends, we get a hash ring as shown in Figure 4: