1. Redis is atomic, so we use the SETNX operation to ensure that only one write ...

kchandra on May 28, 2017 | parent | context | favorite | on: View Counting at Reddit

1. Redis is atomic, so we use the SETNX operation to ensure that only one write succeeds.

2. We have HLLs in Redis, so we just issue a PFCOUNT and store the result of that in Cassandra as an integer value. We don't use counters in Cassandra.