Prajna

Caching is a cop-out Cache stores such as Memcached and Redis are often used to speed up slow database queries or avoid recomputing expensive HTTP responses. Caching is critical for scalability, but it should not become a crutch. It should be introduced only after the underlying performance problem has been understood and other reasonable optimizations have been considered. I think running a cache for every encountered slow query is a cop-out. I believe understanding the cause of performance degradation is key; otherwise, the cache is just a duct-tape. If it is a database query, look at the plan. Do you need an index? Are there a lot of logical reads? Can you rewrite the query or include an additional filter to predict to minimize the search space? If it is an RPC, consider why the calls are chatty in the first place, and can you eliminate the calls at the client side? Oftentimes, libraries and frameworks can issue a fleet of queries when misused. Another reason black-boxes must be understood. After running out of tuning options, a cache might be needed. I emphasis in my fundamentals courses the importance of understanding the root cause, whether a database, backend end point or a networking protocol. If you want to elevate your skill set, check the courses on my website.