Cassandra Partitioning, High Availability, and Consistency - Real-time Analytics with Storm and Cassandra - page 149

• 9 belongs to node H

So as you see, this uses simple hashing to compute the ownership of the key in a ring,
based on owned token range.

Let's look at a practical example of consistent hashing; to explain this let's take a sample
column family where the partition key value is the name.

Let's say the following is the column value data:

Name Gender

Jammy M

Carry F

Jesse M

Sammy F

Here is what the hash-mapping would look like:

Partition key Hash value

Jim 2245462676723220000.00

Carol 7723358927203680000.00

Johnny 6723372854036780000.00

Suzy 1168604627387940000.00

Let's say I have four nodes with the following range; here is how the data would be dis-
tributed: