Caching Flashcards
“What is caching?”
“Caching is a technique that stores frequently accessed data temporarily in a fast storage layer to improve performance and reduce latency.”
“How does caching improve application performance?”
“Caching reduces latency by serving data from a fast storage layer instead of fetching it from a slower database or computation.”
“What are the main benefits of caching?”
“Improved performance, reduced server load, cost-efficiency, and better scalability.”
“What are some challenges of caching?”
“Ensuring cache consistency, handling stale data, and implementing proper cache invalidation strategies.”
“What is client-side caching?”
“Client-side caching stores data locally on the user’s device to minimize server interactions and speed up response times.”
“What are examples of client-side caching mechanisms?”
“Browser cache, local storage, and cookies.”
“What is a drawback of client-side caching?”
“Limited storage capacity and the risk of serving stale data if not properly refreshed.”
“What is CDN caching?”
“CDN caching stores static content on geographically distributed edge servers to serve users from the nearest location.”
“How does a CDN improve performance?”
“It reduces latency by serving content from a nearby server instead of the origin server.”
“What is a challenge in using a CDN?”
“Managing cache invalidation to ensure users always receive updated content.”
“What is web caching?”
“Web caching stores HTTP responses to reduce server load and improve page load times.”
“What are the two main types of web caching?”
“Proxy caching and reverse proxy caching.”
“How does reverse proxy caching work?”
“It caches content on the server-side to reduce the load on application servers.”
“What is database caching?”
“Database caching stores query results or frequently accessed data in a cache layer to reduce database load and improve query response times.”
“Which tools are commonly used for database caching?”
“Redis and Memcached.”
“What is a key challenge of database caching?”
“Ensuring cache consistency with the database and handling cache invalidation.”
“What is application caching?”
“Application caching stores data at the application level to optimize processes and improve responsiveness.”
“What are the types of application caching?”
“Session caching, object caching, and page caching.”
“How does session caching work?”
“It stores user session data in memory for quick retrieval.”
“What is cache aside (lazy loading) caching?”
“Data is loaded into the cache only when requested; if not found, it is retrieved from the database and stored in the cache.”
“What is a benefit of cache aside?”
“It prevents unnecessary caching of rarely accessed data.”
“What is a downside of cache aside?”
“Cache misses can cause delays as the database must be queried first.”
“What is write-through caching?”
“Every time data is written to the database, it is also written to the cache immediately.”
“What is a benefit of write-through caching?”
“Ensures cache consistency with the database.”
“What is a downside of write-through caching?”
“Slower writes due to double updates.”
“What is write-behind caching?”
“Data is written to the cache first and asynchronously updated in the database later.”
“What is a benefit of write-behind caching?”
“Improves write performance as database updates happen in the background.”
“What is a risk of write-behind caching?”
“Data loss if the cache fails before writing to the database.”
“What is refresh-ahead caching?”
“The cache updates data before it expires to prevent stale reads.”
“What is a benefit of refresh-ahead caching?”
“Ensures users always receive fresh data.”
“What is a challenge of refresh-ahead caching?”
“May waste resources updating unused cached data.”
“What is cache invalidation?”
“Cache invalidation is the process of removing or updating outdated data from the cache to ensure consistency with the data source.”
“What are common cache invalidation techniques?”
“Time-to-Live (TTL), manual invalidation, and event-driven updates.”
“How do you handle cache consistency?”
“By using write-through caching, proper TTL settings, and cache invalidation strategies.”
“What is a cache hit?”
“A cache hit occurs when a requested data item is found in the cache, reducing the need for database access.”
“What is a cache miss?”
“A cache miss occurs when requested data is not found in the cache, requiring retrieval from the database or other sources.”
“What is a cache eviction policy?”
“A set of rules determining how old or unused cache entries are removed when space is needed.”
“What are common cache eviction policies?”
“Least Recently Used (LRU), Least Frequently Used (LFU), and First-In, First-Out (FIFO).”
“What is the difference between a distributed cache and a local cache?”
“A distributed cache is shared across multiple nodes, while a local cache exists only within a single application instance.”
“Why is Redis a popular caching solution?”
“Redis is in-memory, supports multiple data structures, and provides high-speed performance.”
“What is Memcached used for?”
“Memcached is used for caching key-value data to improve response times and reduce database load.”
“How does caching help with scalability?”
“By reducing the load on backend systems, caching allows applications to handle more users and traffic efficiently.”
