redis-audit.rb

#!/usr/bin/env ruby

#    Copyright (c) 2012, Simon Maynard
#    http://snmaynard.com
#    
#    Permission is hereby granted, free of charge, to any person obtaining a 
#    copy of this software and associated documentation files (the "Software"), 
#    to deal in the Software without restriction, including without limitation 
#    the rights to use, copy, modify, merge, publish, distribute, sublicense, 
#    and/or sell copies of the Software, and to permit persons to whom the 
#    Software is furnished to do so, subject to the following conditions:
#
#    The above copyright notice and this permission notice shall be included 
#    in all copies or substantial portions of the Software.
#
#    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
#    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
#    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
#    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
#    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
#    CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

require 'bundler/setup'
require 'redis'
require 'redis/connection/hiredis'
require 'optparse'

# Container class for stats around a key group
class KeyStats
  attr_accessor :total_instances, 
                :total_idle_time, 
                :total_serialized_length,
                :total_expirys_set,
                :min_serialized_length,
                :max_serialized_length,
                :min_idle_time,
                :max_idle_time,
                :max_ttl,
                :sample_keys
  
  def initialize
    @total_instances = 0
    @total_idle_time = 0
    @total_serialized_length = 0
    @total_expirys_set = 0
    
    @min_serialized_length = nil
    @max_serialized_length = nil
    @min_idle_time = nil
    @max_idle_time = nil
    @max_ttl = nil
    
    @sample_keys = {}
  end
  
  def add_stats_for_key(key, type, idle_time, serialized_length, ttl)
    @total_instances += 1
    @total_idle_time += idle_time
    @total_expirys_set += 1 if ttl != nil
    @total_serialized_length += serialized_length
    
    @min_idle_time = idle_time if @min_idle_time.nil? || @min_idle_time > idle_time
    @max_idle_time = idle_time if @max_idle_time.nil? || @max_idle_time < idle_time
    @min_serialized_length = serialized_length if @min_serialized_length.nil? || @min_serialized_length > serialized_length
    @max_serialized_length = serialized_length if @max_serialized_length.nil? || @max_serialized_length < serialized_length
    @max_ttl = ttl if ttl != nil && ( @max_ttl == nil || @max_ttl < ttl )
    
    @sample_keys[key] = type if @sample_keys.count < 10
  end
end

class RedisAudit
  @@key_regex = /^(.*):(.*)$/
  @@debug_regex = /serializedlength:(\d*).*lru_seconds_idle:(\d*)/
  
  # Configure regular expressions here if you need to guarantee that certain keys are grouped together
  @@key_group_regex_list = []
  
  def initialize(redis, sample_size)
    @redis = redis
    @keys = Hash.new {|h,k| h[k] = KeyStats.new}
    @sample_size = sample_size
    @dbsize = 0
  end
  
  def audit_keys
    @dbsize = @redis.dbsize.to_i
    
    if @sample_size == 0 || @sample_size.nil?
      @sample_size = (0.1 * @dbsize).to_i
    end
    
    if @sample_size < @dbsize
      puts "Sampling #{@sample_size} keys..."
      sample_progress = @sample_size/10
    
      @sample_size.times do |index|
        key = @redis.randomkey
        audit_key(key)
        if sample_progress > 0 && (index + 1) % sample_progress == 0
          puts "#{index + 1} keys sampled - #{(((index + 1)/@sample_size.to_f) * 100).round}% complete - #{Time.now}"
        end
      end
    else
      sample_progress = @dbsize/10
      
      puts "Getting a list of all #{@dbsize} keys..."
      keys = @redis.keys("*")
      puts "Auditing #{@dbsize} keys..."
      keys.each_with_index do |key, index|
        audit_key(key)
        if sample_progress > 0 && (index + 1) % sample_progress == 0
          puts "#{index + 1} keys sampled - #{(((index + 1)/@dbsize.to_f) * 100).round}% complete - #{Time.now}"
        end
      end
    end
  end
  
  def audit_key(key)
    pipeline = @redis.pipelined do
      @redis.debug("object", key)
      @redis.type(key)
      @redis.ttl(key)
    end
    debug_fields = @@debug_regex.match(pipeline[0])
    serialized_length = debug_fields[1].to_i
    idle_time = debug_fields[2].to_i
    type = pipeline[1]
    ttl = pipeline[2] == -1 ? nil : pipeline[2]
    @keys[group_key(key, type)].add_stats_for_key(key, type, idle_time, serialized_length, ttl)
  rescue Redis::CommandError
    $stderr.puts "Skipping key #{key}"
  end
  
  # This function defines what keys are grouped together. Currently it looks for a key that
  # matches at least a third of the key from the start, and groups those together. It also 
  # removes any numbers as they are (generally) ids. 
  def group_key(key, type)
    @@key_group_regex_list.each_with_index do |regex, index|
      return "#{regex.to_s}:#{type}" if regex.match(key)
    end
    
    # This makes the odds of finding a correct match higher, as mostly these are ids
    key = key.delete("0-9")
    
    matching_key = nil
    length_of_best_match = 0
    threshold = key.length / 3
    matching_portion = nil
    key_codepoints = key.codepoints.to_a
    
    @keys.keys.each do |current_key|
      next if matching_key && !current_key.start_with?(matching_portion) # we know it wont be longer
      length_of_match = 0
      
      current_key.each_codepoint.with_index do |codepoint, index|
        next if index < length_of_best_match
        break unless key_codepoints[index] == codepoint
        length_of_match += 1
      end
      
      # Minimum length of match is 1/3 of the new key length
      if length_of_match >= threshold && length_of_match > length_of_best_match && @@key_regex.match(current_key)[2] == type
        matching_key = current_key
        length_of_best_match = length_of_match
        matching_portion = matching_key[0...length_of_match]
      end
    end
    if matching_key != nil
      return matching_key
    else
      return "#{key}:#{type}"
    end
  end
  
  def output_duration(seconds)
    m, s = seconds.divmod(60)
    h, m = m.divmod(60)
    d, h = h.divmod(24)
    
    output = []
    output << "#{d} days" if d != 0
    output << "#{h} hours" if h != 0
    output << "#{m} minutes" if m != 0
    output << "#{s} seconds" if s != 0
    return "0 seconds" if output.count == 0
    return output.join(", ") 
  end
  
  def output_bytes(bytes)
    kb, b = bytes.divmod(1024)
    mb, kb = kb.divmod(1024)
    gb, mb = mb.divmod(1024)
    
    if gb != 0
      result = ((gb + mb/1024.0)*100).round()/100.0
      return "#{result} GB"
    elsif mb != 0
      result = ((mb + kb/1024.0)*100).round()/100.0
      return "#{result} MB"
    elsif kb != 0
      result = ((kb + b/1024.0)*100).round()/100.0
      return "#{result} kB"
    else
      return "#{b} bytes"
    end
  end
  
  def output_stats
    complete_serialized_length = @keys.map {|key, value| value.total_serialized_length }.reduce(:+)
    sorted_keys = @keys.keys.sort{|a,b| @keys[a].total_serialized_length <=> @keys[b].total_serialized_length}
    
    if complete_serialized_length == 0 || complete_serialized_length.nil?
      complete_serialized_length = 0
    end

    puts "DB has #{@dbsize} keys"
    puts "Sampled #{output_bytes(complete_serialized_length)} of Redis memory"
    puts
    puts "Found #{@keys.count} key groups"
    puts
    sorted_keys.each do |key|
      value = @keys[key]
      key_fields = @@key_regex.match(key)
      common_key = key_fields[1]
      common_type = key_fields[2]
      
      puts "=============================================================================="
      puts "Found #{value.total_instances} keys containing #{common_type}s, like:"
      puts "\e[0;33m#{value.sample_keys.keys.join(", ")}\e[0m"
      puts
      puts "These keys use \e[0;1;4m#{make_proportion_percentage(value.total_serialized_length/complete_serialized_length.to_f)}\e[0m of the total sampled memory (#{output_bytes(value.total_serialized_length)})"
      if value.total_expirys_set == 0
        puts "\e[0;1;4mNone\e[0m of these keys expire"
      else
        puts "\e[0;1;4m#{make_proportion_percentage(value.total_expirys_set/value.total_instances.to_f)}\e[0m of these keys expire (#{value.total_expirys_set}), with maximum ttl of #{output_duration(value.max_ttl)}"
      end
      
      puts "Average last accessed time: \e[0;1;4m#{output_duration(value.total_idle_time/value.total_instances)}\e[0m - (Max: #{output_duration(value.max_idle_time)} Min:#{output_duration(value.min_idle_time)})"
      puts
    end
    summary_columns = [{
      :title => "Key",
      :width => 50
    },{
      :title => "Memory Usage",
      :width => 12
    },{
      :title => "Expiry Proportion",
      :width => 17
    },{
      :title => "Last Access Time",
      :width => 50
    }]
    format = summary_columns.map{|c| "%-#{c[:width]}s" }.join(' | ')
    
    puts "=============================================================================="
    puts "Summary"
    puts
    puts format.tr(' |', '-+') % summary_columns.map{|c| '-'*c[:width] }
    puts format % summary_columns.map{|c| c[:title]}
    puts format.tr(' |', '-+') % summary_columns.map{|c| '-'*c[:width] }
    sorted_keys.reverse.each do |key|
      value = @keys[key]
      puts format % [value.sample_keys.keys[0][0...50], make_proportion_percentage(value.total_serialized_length/complete_serialized_length.to_f), make_proportion_percentage(value.total_expirys_set/value.total_instances.to_f), output_duration(value.min_idle_time)[0...50]]
    end
    puts format.tr(' |', '-+') % summary_columns.map{|c| '-'*c[:width] }
  end
  
  def make_proportion_percentage(value)
    return "#{(value * 10000).round/100.0}%"
  end
end

# take in our command line options and parse
options = {}
OptionParser.new do |opts|
  opts.banner = "Usage: redis-audit.rb [options]"

  opts.on("-u", "--url URL", "Connection Url") do |url|
    options[:url] = url
  end

  opts.on("-h", "--host HOST", "Redis Host") do |host|
    options[:host] = host
  end

  opts.on("-p", "--port PORT", "Redis Port") do |port|
    options[:port] = port
  end

  opts.on("-a", "--password PASSWORD", "Redis Password") do |password|
    options[:password] = password
  end

  opts.on("-d", "--dbnum DBNUM", "Redis DB Number") do |dbnum|
    options[:dbnum] = dbnum
  end

  opts.on("-s", "--sample NUM", "Sample Size") do |sample_size|
    options[:sample_size] = sample_size.to_i
  end

  opts.on('--help', 'Displays Help') do
    puts opts
    exit
  end
end.parse!

# allows non-paramaterized/backwards compatible command line
if options[:host].nil? && options[:url].nil?
  if ARGV.length < 4 || ARGV.length > 5
    puts "Run redis-audit.rb --help for information on how to use this tool."
    exit 1
  else
    options[:host] = ARGV[0]
    options[:port] = ARGV[1].to_i
    options[:password] = ARGV[2].to_i
    options[:dbnum] = ARGV[3].to_i
    options[:sample_size] = ARGV[4].to_i
  end
end

# create our connection to the redis db
if !options[:url].nil?
  redis = Redis.new(:url => options[:url])
else
  # with url empty, assume that --host has been set, but since we don't enforce
  # port or dbnum to be set, allow sane defaults
  # set default port if no port is set
  if options[:port].nil?
    options[:port] = 6379
  end
  # set default dbnum if no dbnum is set
  if options[:dbnum].nil?
    options[:dbnum] = 0
  end
  # don't pass the password argument unless it is set
  if options[:password].nil?
    redis = Redis.new(:host => options[:host], :port => options[:port], :db => options[:dbnum])
  else
    redis = Redis.new(:host => options[:host], :port => options[:port], :password => options[:password], :db => options[:dbnum])
  end
end

# set sample_size to a default if not passed in
if options[:sample_size].nil?
  options[:sample_size] = 0
end

# audit our data
auditor = RedisAudit.new(redis, options[:sample_size])
if !options[:url].nil?
  puts "Auditing #{options[:url]} sampling #{options[:sample_size]} keys"
else
  puts "Auditing #{options[:host]}:#{options[:port]} dbnum:#{options[:dbnum]} sampling #{options[:sample_size]} keys"
end
auditor.audit_keys
auditor.output_stats