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A redis clone in Python 3 to disprove some falsehoods about performance.
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csv benchmark suite ready Mar 1, 2019
LICENSE Added "Donations" section to README Mar 9, 2019


pydis is an experiment to disprove some of the falsehoods about performance and optimisation regarding software and interpreted languages in particular.

Unfortunately many programmers, due to their lack of experience, of some knowledge of computer architecture(s), or of an in-depth understanding of the task they are given, spend countless hours by making life harder for themselves in the name of marginal performance gains, often trading many other conveniences (such as type safety, garbage collection, etc) too.

Below you will find a Redis clone, pydis, written in < 250 lines of idiomatic Python code, providing a subset of redis' functionality for which there are official benchmarks.

Briefly, pydis is ~60% as fast as Redis measured in number operations per second.

P.S. This is not a criticism of Redis, which is a brilliant project and a system-level software that powers thousands of infrastructures. It just happened to be one of the fastest software I could imagine and clone the same day.


redis-benchmark -q -t set,get,incr,lpush,rpush,lpop,rpop,sadd,hset,spop,lrange,mset -n 100000 -P 5 
  • 100,000 requests in total per command.
  • Requests are pipelined in groups of 5.

The Bar Graph

Benchmark pydis redis Ratio
SET 301,582 379,944 0.794
GET 264,841 455,237 0.582
INCR 238,670 442,483 0.539
LPUSH 246,867 386,442 0.639
RPUSH 258,845 376,787 0.687
LPOP 297,397 355,276 0.837
RPOP 280,095 399,511 0.701
SADD 223,700 416,842 0.537
HSET 240,649 367,985 0.654
SPOP 285,936 442,747 0.646
LRANGE (100) 26,162 99,703 0.262
LRANGE (300) 9,135 21,211 0.431
LRANGE (500) 5,788 14,649 0.395
LRANGE (600) 4,339 10,659 0.407
MSET 157,963 172,226 0.917

Host System

  • Ubuntu 18.04
  • Python 3.6.7 (GCC 8.2.0)
  • Redis 4.0.9 malloc=jemalloc-3.6.0 bits=64 build=76095d16786fbcba




Cryptocurrencies (Coinbase)

  • BTC: 3BLWjamWug3QQzcDDGwYLwuCqJyjcfYJB8
  • LTC: MRWX5SGCF7EvN15gpzT5b3KQD3Z91gH8qi
  • BCH: qqn07a58hax9l8pckq9j8ys6dsh2cnu4rsyztw2kj9
  • ETH: 0xe5A8e80bAA6129DF7eBB1B5302F9e2Ef4C6f6E62
  • ETC: 0x8964EcC86eaf043Bff2CdfE875E73D8095c26a58


Contributions are very welcome, given that they fall into one of the following categories:

  • Those that improve the performance.
    • The aim of this exercise is to prove that interpreted languages can be just as fast as C. So whilst using a faster parser in C with Python bindings is okay, rewriting pydis in Cython is not.
    • I will accept "minor" deviations from idioms only if the performance gains are worth it; stick to idiomatic Python otherwise!
  • Those to achieve feature parity with Redis for which there are official benchmarks.
    • We are not trying to develop a full-featured Redis clone here so please do not implement commands for which there are no official benchmarks.
  • Those that fix formatting etc.
    • Please do not invent your own style, use PEP 8.
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