Memcached:  a general-purpose distributed memory caching system

Memcached is a general-purpose distributed memory caching system that is aimed at speeding up dynamic database-driven websites. It is used to reduce the number of times an external data source (like a database or API) is read by caching data and objects in RAM. The Memcached system uses a client–server architecture. The server maintain a key–value associative array, while the clients populate this array and query it. Keys are up to 250 bytes long and...

Redis: an open source in-memory data structure store

Redis is an open source, in-memory data structure store, used as a database, cache and message broker. It supports data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs and geospatial indexes with radius queries. Redis has built-in replication, Lua scripting, LRU eviction, transactions and different levels of on-disk persistence, and provides high availability via Redis Sentinel and automatic partitioning with Redis Cluster. Many popular languages use Redis bindings, including:...

The Computer CPU – Principles Of Execution

The real complexity of any computer system resides in the processor, but do you know how it works? I mean how it really works? How does the code that you write turn into something that does something? When you know how, it’s not magic – just a matter of “fetch” and “execute”. So far we have looked at the overall workings of a computer and specifically the memory principle. Memories are devices that when given...