While using a Redis database for speeding up an application, cache eviction policies become critical as data volume increases and the cache fills up. Understanding cache eviction is essential for achieving optimal performance and consistency. Cache eviction strategies dictate how to remove specific data from a cache when it reaches its maximum storage capacity. The effectiveness of these strategies depends on the specific use case, and setting the right policy can prevent potential headaches. Monitoring tools like Redis's INFO command and third-party tools like New Relic and Datadog are crucial for determining when to act and tuning cache performance. Understanding the intricacies of scaling cache with Redis is vital for achieving reliable and efficient caching solutions for diverse applications.