Benchmarking redis gem vs hiredis vs custom Redis client

benchmark.rb

require 'bundler/inline'

require 'socket'
class MyRedis
  CRLF = "\r\n"

  def initialize
    @connection = TCPSocket.new('localhost', 6379)
    @connection.sync = false
  end

  def get(key)
    @connection << "*2\r\n$3\r\nget\r\n$#{key.bytesize}\r\n#{key}\r\n"
    @connection.flush
    result = @connection.gets
    if result.start_with?('$')
      value = ''
      bytesize = result.tap { |r| r[0] = '' }.to_i
      return nil if bytesize < 0 # Key does not exist
      @connection.read bytesize + 2, value
      value.chomp! CRLF
      value
    else
      raise "idk what to do with this: #{result.inspect}"
    end
  end
end

gemfile true do
  source 'https://rubygems.org'
  gem 'redis'
  gem 'hiredis'
  gem 'benchmark-ips'
end

require 'benchmark'
require 'benchmark/ips'
require 'redis'
require 'hiredis'

redis = Redis.new(driver: :ruby)
hiredis = Redis.new(driver: :hiredis)
myredis = MyRedis.new
key = "foo"
cpu_time_iterations = 100_000

# Quick functionality check on our custom Redis
redis.set key, "test"
if (myredis_value = myredis.get(key)) == (redis_value = redis.get(key))
  puts "Cache-hit function check passed"
else
  raise "Value mismatch. Redis: #{redis_value.inspect}, MyRedis: #{myredis_value.inspect}"
end
redis.del key
if myredis_value = myredis.get(key).nil?
  puts "Cache-miss function check passed"
else
  raise "MyRedis cache miss broken: #{myredis_value.inspect}"
end


puts
puts "Cache hit (returns a 2KB string)"
redis.set key, "." * 2048 # 2KB cache entry
Benchmark.ips do |x|
  x.report("ruby") { redis.get key }
  x.report("hiredis") { hiredis.get key }
  x.report("myredis") { myredis.get key  }

  x.compare!
end

puts
puts "Cache hit CPU time"
puts "ruby   : #{Benchmark.measure { cpu_time_iterations.times { redis.get key } }.total}"
puts "hiredis: #{Benchmark.measure { cpu_time_iterations.times { hiredis.get key } }.total}"
puts "myredis: #{Benchmark.measure { cpu_time_iterations.times { myredis.get key } }.total}"

puts
puts "Cache miss (returns nil)"
redis.del key
Benchmark.ips do |x|
  x.report("ruby") { redis.get key }
  x.report("hiredis") { hiredis.get key }
  x.report("myredis") { myredis.get key  }

  x.compare!
end

puts
puts "Cache miss CPU time"
puts "ruby   : #{Benchmark.measure { cpu_time_iterations.times { redis.get key } }.total}"
puts "hiredis: #{Benchmark.measure { cpu_time_iterations.times { hiredis.get key } }.total}"
puts "myredis: #{Benchmark.measure { cpu_time_iterations.times { myredis.get key } }.total}"

output-intel.txt

Fetching gem metadata from https://rubygems.org/....
Resolving dependencies...
Using benchmark-ips 2.8.4
Using bundler 2.2.3
Using hiredis 0.6.3
Using redis 4.2.5
Cache-hit function check passed
Cache-miss function check passed

Cache hit (returns a 2KB string)
Warming up --------------------------------------
                ruby     1.857k i/100ms
             hiredis     3.124k i/100ms
             myredis     3.184k i/100ms
Calculating -------------------------------------
                ruby     22.082k (±14.1%) i/s -    107.706k in   5.021179s
             hiredis     31.506k (± 1.7%) i/s -    159.324k in   5.058568s
             myredis     31.997k (± 2.8%) i/s -    162.384k in   5.079019s

Comparison:
             myredis:    31997.4 i/s
             hiredis:    31505.6 i/s - same-ish: difference falls within error
                ruby:    22081.8 i/s - 1.45x  (± 0.00) slower


Cache hit CPU time
ruby   : 3.7590459999999997
hiredis: 1.9650980000000011
myredis: 1.7395270000000007

Cache miss (returns nil)
Warming up --------------------------------------
                ruby     2.666k i/100ms
             hiredis     3.352k i/100ms
             myredis     3.440k i/100ms
Calculating -------------------------------------
                ruby     25.796k (± 8.2%) i/s -    127.968k in   5.006173s
             hiredis     33.267k (± 1.0%) i/s -    167.600k in   5.038516s
             myredis     34.693k (± 2.3%) i/s -    175.440k in   5.059694s

Comparison:
             myredis:    34693.1 i/s
             hiredis:    33267.0 i/s - 1.04x  (± 0.00) slower
                ruby:    25795.8 i/s - 1.34x  (± 0.00) slower


Cache miss CPU time
ruby   : 3.0532809999999984
hiredis: 1.840083
myredis: 1.5741099999999975

output-m1.txt

Fetching gem metadata from https://rubygems.org/....
Resolving dependencies...
Using bundler 2.2.15
Using hiredis 0.6.3
Using redis 4.2.5
Using benchmark-ips 2.8.4
Cache-hit function check passed
Cache-miss function check passed

Cache hit (returns a 2KB string)
Warming up --------------------------------------
                ruby     2.638k i/100ms
             hiredis     5.080k i/100ms
             myredis     5.741k i/100ms
Calculating -------------------------------------
                ruby     35.924k (±12.0%) i/s -    176.746k in   5.013467s
             hiredis     52.624k (± 4.7%) i/s -    264.160k in   5.034100s
             myredis     59.541k (± 1.1%) i/s -    298.532k in   5.014476s

Comparison:
             myredis:    59541.4 i/s
             hiredis:    52623.8 i/s - 1.13x  (± 0.00) slower
                ruby:    35924.1 i/s - 1.66x  (± 0.00) slower


Cache hit CPU time
ruby   : 1.751384999999999
hiredis: 0.9159620000000004
myredis: 0.6444190000000001

Cache miss (returns nil)
Warming up --------------------------------------
                ruby     4.234k i/100ms
             hiredis     5.594k i/100ms
             myredis     6.340k i/100ms
Calculating -------------------------------------
                ruby     42.602k (± 9.1%) i/s -    211.700k in   5.020637s
             hiredis     55.257k (± 4.7%) i/s -    279.700k in   5.074557s
             myredis     63.400k (± 1.6%) i/s -    317.000k in   5.001319s

Comparison:
             myredis:    63399.9 i/s
             hiredis:    55256.9 i/s - 1.15x  (± 0.00) slower
                ruby:    42601.6 i/s - 1.49x  (± 0.00) slower


Cache miss CPU time
ruby   : 1.417432999999999
hiredis: 0.832987000000001
myredis: 0.5722979999999982