Caching

Question 1

“What is caching?”

Answer 1

“Caching is a technique that stores frequently accessed data temporarily in a fast storage layer to improve performance and reduce latency.”

Question 2

“How does caching improve application performance?”

Answer 2

“Caching reduces latency by serving data from a fast storage layer instead of fetching it from a slower database or computation.”

Question 3

“What are the main benefits of caching?”

Answer 3

“Improved performance, reduced server load, cost-efficiency, and better scalability.”

Question 4

“What are some challenges of caching?”

Answer 4

“Ensuring cache consistency, handling stale data, and implementing proper cache invalidation strategies.”

Question 5

“What is client-side caching?”

Answer 5

“Client-side caching stores data locally on the user’s device to minimize server interactions and speed up response times.”

Question 6

“What are examples of client-side caching mechanisms?”

Answer 6

“Browser cache, local storage, and cookies.”

Question 7

“What is a drawback of client-side caching?”

Answer 7

“Limited storage capacity and the risk of serving stale data if not properly refreshed.”

Question 8

“What is CDN caching?”

Answer 8

“CDN caching stores static content on geographically distributed edge servers to serve users from the nearest location.”

Question 9

“How does a CDN improve performance?”

Answer 9

“It reduces latency by serving content from a nearby server instead of the origin server.”

Question 10

“What is a challenge in using a CDN?”

Answer 10

“Managing cache invalidation to ensure users always receive updated content.”

Question 11

“What is web caching?”

Answer 11

“Web caching stores HTTP responses to reduce server load and improve page load times.”

Question 12

“What are the two main types of web caching?”

Answer 12

“Proxy caching and reverse proxy caching.”

Question 13

“How does reverse proxy caching work?”

Answer 13

“It caches content on the server-side to reduce the load on application servers.”

Question 14

“What is database caching?”

Answer 14

“Database caching stores query results or frequently accessed data in a cache layer to reduce database load and improve query response times.”

Question 15

“Which tools are commonly used for database caching?”

Answer 15

“Redis and Memcached.”

Question 16

“What is a key challenge of database caching?”

Answer 16

“Ensuring cache consistency with the database and handling cache invalidation.”

Question 17

“What is application caching?”

Answer 17

“Application caching stores data at the application level to optimize processes and improve responsiveness.”

Question 18

“What are the types of application caching?”

Answer 18

“Session caching, object caching, and page caching.”

Question 19

“How does session caching work?”

Answer 19

“It stores user session data in memory for quick retrieval.”

Question 20

“What is cache aside (lazy loading) caching?”

Answer 20

“Data is loaded into the cache only when requested; if not found, it is retrieved from the database and stored in the cache.”

Question 21

“What is a benefit of cache aside?”

Answer 21

“It prevents unnecessary caching of rarely accessed data.”

Question 22

“What is a downside of cache aside?”

Answer 22

“Cache misses can cause delays as the database must be queried first.”

Question 23

“What is write-through caching?”

Answer 23

“Every time data is written to the database, it is also written to the cache immediately.”

Question 24

“What is a benefit of write-through caching?”

Answer 24

“Ensures cache consistency with the database.”

Question 25

“What is a downside of write-through caching?”

Answer 25

“Slower writes due to double updates.”

Question 26

“What is write-behind caching?”

Answer 26

“Data is written to the cache first and asynchronously updated in the database later.”

Question 27

“What is a benefit of write-behind caching?”

Answer 27

“Improves write performance as database updates happen in the background.”

Question 28

“What is a risk of write-behind caching?”

Answer 28

“Data loss if the cache fails before writing to the database.”

Question 29

“What is refresh-ahead caching?”

Answer 29

“The cache updates data before it expires to prevent stale reads.”

Question 30

“What is a benefit of refresh-ahead caching?”

Answer 30

“Ensures users always receive fresh data.”

Question 31

“What is a challenge of refresh-ahead caching?”

Answer 31

“May waste resources updating unused cached data.”

Question 32

“What is cache invalidation?”

Answer 32

“Cache invalidation is the process of removing or updating outdated data from the cache to ensure consistency with the data source.”

Question 33

“What are common cache invalidation techniques?”

Answer 33

“Time-to-Live (TTL), manual invalidation, and event-driven updates.”

Question 34

“How do you handle cache consistency?”

Answer 34

“By using write-through caching, proper TTL settings, and cache invalidation strategies.”

Question 35

“What is a cache hit?”

Answer 35

“A cache hit occurs when a requested data item is found in the cache, reducing the need for database access.”

Question 36

“What is a cache miss?”

Answer 36

“A cache miss occurs when requested data is not found in the cache, requiring retrieval from the database or other sources.”

Question 37

“What is a cache eviction policy?”

Answer 37

“A set of rules determining how old or unused cache entries are removed when space is needed.”

Question 38

“What are common cache eviction policies?”

Answer 38

“Least Recently Used (LRU), Least Frequently Used (LFU), and First-In, First-Out (FIFO).”

Question 39

“What is the difference between a distributed cache and a local cache?”

Answer 39

“A distributed cache is shared across multiple nodes, while a local cache exists only within a single application instance.”

Question 40

“Why is Redis a popular caching solution?”

Answer 40

“Redis is in-memory, supports multiple data structures, and provides high-speed performance.”

Question 41

“What is Memcached used for?”

Answer 41

“Memcached is used for caching key-value data to improve response times and reduce database load.”

Question 42

“How does caching help with scalability?”

Answer 42

“By reducing the load on backend systems, caching allows applications to handle more users and traffic efficiently.”