rustcached - 用rust实现的一个memcached克隆

jopen 9年前

rustcached - 用rust实现的一个memcached克隆

Features:

  • Aside from what's listed in Missing below, we support all memcached commands and are fully compatible

Missing:

  • binary protocol
  • stats
  • UDP
  • unix sockets
  • delete with expires (memcached dropped this support in 1.4)
  • flush_all with expires
  • verbosity is recognised but ignored
  • SASL

Performance

rustcache is about half as fast as memcached according to memslap:

rustcached:

$ memslap --servers=localhost:11211 --test=set --concurrency=10 --debug --execute-number=10000 --flag --flush      Threads connecting to servers 10      Took 3.145 seconds to load data  $ memslap --servers=localhost:11211 --test=get --concurrency=10 --debug --execute-number=10000 --flag --flush      Threads connecting to servers 10      Took 4.976 seconds to read data

memcached:

$ memslap --servers=localhost:11212 --test=set --concurrency=10 --debug --execute-number=10000 --flag --flush      Threads connecting to servers 10      Took 2.736 seconds to load data  $ memslap --servers=localhost:11212 --test=get --concurrency=10 --debug --execute-number=10000 --flag --flush      Threads connecting to servers 10      Took 3.933 seconds to read data

Code organisation:

  • cmd.rs: control starts here, command line arguments parsed, and the server started
  • store.rs: houses the memcached application logic (e.g. what does "add" mean and how do I apply it?)
  • lru.rs: the LRU cache
  • parser.rs: protocol parsing
  • server.rs: socket handling and response writing

Todo:

  • We're using the default rust allocator (jemalloc) for everything, instead of a slab allocator like memcached
  • you can exhaust memory in the parser with an unlimited key/value length
  • you can't set values larger than the memcached length limits, but you can append/prepend past them
  • We copy a lot of stuff around right now that we don't have to, especially in the response builder
  • lru.rs uses Arc<T> but there's probably a way to just use Rc<T> when we go single-threaded

Future features:

  • we use LRU right now like memcached does, but I want to try ARC in a real environment
  • eager deletion of expired items during idle periods

项目地址： https://github.com/ketralnis/rustcached