Twitter : Find out Twemproxy : To bound the number of connections on the cache servers from africa

Twemproxy is used by Twitter to bound the number of connections on the cache servers by deploying it as a local proxy on each of the front-ends. The Unicorns on each front-end connect to the cache servers through the local proxy, which multiplexes and pipelines the front-end requests over a single connection to each cache server. This reduces the number of connections to each cache server by a significant factor.

Twemproxy has been instrumental in allowing front-end and cache server pools to scale independently as capacity requirements change.

Actually Twemproxy can:

• Maintain persistent server connections
• Keep connection count on cache servers low
• Pipeline requests and responses
• Use multiple server pools simultaneously
• Proxy the complete memcached ASCII protocol
• Easily configure server pools using a YAML file
• Use multiple hashing modes, including consistent hashing
• Increase observability using stats exposed on a monitoring port