How do you handle a hot partition problem in Cassandra?

Hot partition = one partition gets disproportionate traffic: 1) Detection: nodetool tpstats shows one node overwhelmed; cfhistograms for latency distribution by partition. 2) Causes: bad partition key (low cardinality like status:ACTIVE), or one entity has massive data (one celebrity's posts). 3) Solutions: a) Add bucket to partition key: {(user_id, bucket_date), event_time} instead of just {user_