During a festival, almost every write for a street-closure feed uses one popular event id as the partition key and one shard saturates. What problem is this?
Select an answer to reveal the explanation.
Short Explanation
When one festival event id eats nearly every write, that partition becomes the crowded checkout lane. That is a hot key, not a CAP theorem gotcha or proof that partitioning does not matter. Spread the key design or you cook one shard.
Full Explanation
Hot partitions occur when a skewed key concentrates traffic on one shard while others stay idle. Using a single popular event id as the partition key for most festival writes is a classic imbalance. CAP theorem does not forbid festival data; even distribution is the opposite of this symptom; HDFS NameNode failover is unrelated to NoSQL partition hotspots.