What is cache consistency and why is it important?

What is cache consistency and why is it important?

Cache consistency refers to the uniformity of data stored in cache memory across multiple nodes in a distributed system. It's crucial because it ensures that all users see the same data at the same time, preventing issues like stale data.

How does cache inconsistency occur?

Cache inconsistency can occur due to various reasons, such as concurrent updates to the data, network partitions, or failures in communication between nodes. When one node updates its cache without informing others, inconsistencies arise.

What are some strategies to maintain cache consistency?

Some strategies include using cache coherence protocols, implementing write-through or write-back caching, and employing distributed locking mechanisms to synchronize updates.

Can you explain the difference between strong and eventual consistency?

Strong consistency ensures that all reads return the most recent write, while eventual consistency guarantees that, given enough time, all updates will propagate to all nodes, but not necessarily immediately.

What are the trade-offs between different consistency models?

The trade-offs often involve balancing performance and availability against the accuracy of data. Strong consistency can lead to higher latency, while eventual consistency may improve performance but risks serving stale data.