sergey-alekseev

Keybase proof

I hereby claim:

• I am sergey-alekseev on github.
• I am sergeyalekseev (https://keybase.io/sergeyalekseev) on keybase.
• I have a public key whose fingerprint is 2D4B 460A 441B D5A9 F42E 97A9 781C 4863 C8D7 8D81

To claim this, I am signing this object:

sergey-alekseev

=========== [mysql2] Single column with unique index (1000 records) ============

Warming up --------------------------------------
validate_only_if_changed_by_default = true
                         2.014k i/100ms
validate_only_if_changed_by_default = false
                       227.000  i/100ms
Calculating -------------------------------------
validate_only_if_changed_by_default = true
                         21.060k (± 3.1%) i/s -    106.742k in   5.073537s

sergey-alekseev

# this is a simple Ruby script written by https://github.com/sergey-alekseev
# to automate dummy "UP"s for adverts on the most popular local Belarusian
# online flea market – http://baraholka.onliner.by
# feel free to create a recurring task from the script 
# using launchd on Mac or cron on Linux

begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"

sergey-alekseev

begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"
  raise e
end

gemfile(true) do
  source "https://rubygems.org"
  gem "rails", github: "rails/rails"

sergey-alekseev

input {
  # Read all documents from Elasticsearch matching the given query
  elasticsearch {
    hosts => "localhost"
    index => "index_name"
    query => '{"query":{"regexp":{"not_analyzed_field":".*"}}}'
  }
}

output {

sergey-alekseev

Finding a Ruby memory leak using a time analysis

When developing a program in Ruby, you may sometimes encounter a memory leak. For a while now, Ruby has a facility to gather information about what objects are laying around: ObjectSpace.

There are several approaches one can take to debug a leak. This discusses a time-based approach, where a full memory dump is generated every, say, 5 minutes, during a time that the memory leak is showing up. Afterwards, one can look at all the objects, and find out which ones are staying around, causing the

sergey-alekseev

Benchmark.ips do |x|
  x.report('merge')  { {}.merge  :a => 1 }  
  x.report('merge!') { {}.merge! :a => 1 }  
  x.compare!  
end  
Calculating -------------------------------------
               merge    34.220k i/100ms
              merge!    33.039k i/100ms
-------------------------------------------------
               merge      1.923M (±32.2%) i/s -      7.631M

sergey-alekseev

Benchmark.ips do |x|
  x.report('exists?')    { User.exists?(:id => 1)    }
  x.report('where-any?') { User.where(:id => 1).any? }
  x.compare!
end

Comparison:
             exists?:      636.0 i/s
          where-any?:      567.1 i/s - 1.12x slower

sergey-alekseev

Benchmark.ips do |x|
  x.report('exists?') { user.printers.exists? }
  x.report('any?')    { user.printers.any?    }
  x.compare!
end

Comparison:
                any?:      615.6 i/s
             exists?:      601.8 i/s - 1.02x slower

sergey-alekseev

Benchmark.ips do |x|
  x.report('object comparison') { item.user    == print.user    }
  x.report('id comparison')     { item.user_id == print.user_id }
  x.compare!
end

Calculating -------------------------------------
    object comparison 1.204k i/100ms
    id comparison     1.972k i/100ms
-------------------------------------------------