Redis achieves high performance through its memory-centric design and optimization techniques like pipelining, batched writes, and LRU eviction. Although Redis is single-threaded, it can be scaled horizontally with sharding techniques and supports Lua scripting for complex atomic operations.
Redis employs asynchronous I/O to handle multiple connections simultaneously, allowing clients to send multiple commands without waiting for a response after each command, resulting in efficient execution of multiple commands in a single round-trip to the server.
Here's an example of how Redis handles multiple connections simultaneously using asynchronous I/O:
In the above example, the Redis client sends three commands to the server (
INCR) without waiting for a response after each command. The
pipeline() method returns a pipeline object that allows multiple commands to be executed in a single round-trip to the server. The
execute() method sends all the commands to the server and waits for the responses, returning a list of responses in the order that the commands were sent.