Cluster mode

.gitignore

@@ -1,2 +1,4 @@
 .bundle/
 vendor/
+# Remove if using rbenv
+.ruby-version

Gemfile

@@ -1,4 +1,7 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
-gem 'redis'
 gem 'hiredis'
+gem 'redis'
+gem 'redis-clustering'

Gemfile.lock

@@ -1,8 +1,12 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    hiredis (0.6.0)
-    redis (3.2.2)
+    connection_pool (2.4.1)
+    hiredis (0.6.3)
+    redis (5.1.0)
+      redis-client (>= 0.17.0)
+    redis-client (0.21.0)
+      connection_pool
 
 PLATFORMS
   ruby
@@ -12,4 +16,4 @@ DEPENDENCIES
   redis
 
 BUNDLED WITH
-   1.11.2
+   2.4.19

README.md

@@ -2,7 +2,7 @@
 
 This script samples a number of the Redis keys in a database and then groups them with other *similar* looking keys. It then displays key 
 metrics around those groups of keys to help you spot where efficiencies can be made in the memory usage of your Redis database.  
-_Warning_: The script cannot be used with AWS Elasticache Redis instances, as the debug command is restricted.
+_Warning_: The script cannot provide idle time on AWS Elasticache Redis instances, as the debug command is restricted.  Use the memory flag instead.
 
 ## Installation
    `bundle install` will take care of everything!
@@ -24,7 +24,7 @@ The legacy option looks like this:
 
 You can also specify the arguments with declarations, which also adds the ability to use a Redis URL and pass in authentication credentials:
 
-    redis-audit.rb -h/--host [host] -p/--port [port] -a/--password [password] -d/--dbnum [dbnum] -s/--sample [(optional)sample_size]
+    redis-audit.rb -h/--host [host] -p/--port [port] -a/--password [password] -d/--dbnum [dbnum] -s/--sample [(optional)sample_size] -c/--cluster (optional) -m/--memory (optional)
 
     or
 
@@ -39,6 +39,8 @@ will enable you to see that keys are being grouped properly. If you omit this pa
 greater than the number of keys in the database the script will walk all the keys in the Redis database. **DO NOT** run this with a lot of keys on 
 a production master database. Keys * will block for a long time and cause timeouts!
 - **Url**: Follows the normal syntax for Redis Urls
+- **Cluster Mode**: Connect to a cluster endpoint
+- **Memory Flag**: Use the memory command for key sizing.  Idle time will not be available if this flag is used.
 
 `redis-audit.rb --help` will print out the argument options as well.
 

redis-audit.rb

@@ -22,7 +22,8 @@
 
 require 'bundler/setup'
 require 'redis'
-require 'redis/connection/hiredis'
+require 'redis-clustering'
+require 'hiredis'
 require 'optparse'
 
 # Container class for stats around a key group
@@ -76,11 +77,12 @@ class RedisAudit
   # Configure regular expressions here if you need to guarantee that certain keys are grouped together
   @@key_group_regex_list = []
 
-  def initialize(redis, sample_size)
+  def initialize(redis, sample_size, use_memory)
     @redis = redis
     @keys = Hash.new {|h,k| h[k] = KeyStats.new}
     @sample_size = sample_size
     @dbsize = 0
+    @use_memory = use_memory
   end
 
   def audit_keys
@@ -117,14 +119,23 @@ def audit_keys
   end
 
   def audit_key(key)
-    pipeline = @redis.pipelined do
-      @redis.debug("object", key)
-      @redis.type(key)
-      @redis.ttl(key)
+    pipeline = @redis.pipelined {|p|
+      if @use_memory
+        p.memory("usage", key)
+      else
+        p.debug("object", key)
+      end
+      p.type(key)
+      p.ttl(key)
+    }
+    if @use_memory
+      serialized_length = pipeline[0].nil? ? 0 : pipeline[0]
+      idle_time = 1
+    else
+      debug_fields = @@debug_regex.match(pipeline[0])
+      serialized_length = debug_fields[1].to_i
+      idle_time = debug_fields[2].to_i
     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)
@@ -301,6 +312,15 @@ def make_proportion_percentage(value)
     options[:sample_size] = sample_size.to_i
   end
 
+  # Note: Cluster mode and memory flag not present in backwards compatible command line
+  opts.on("-c", "--cluster", "Cluster Mode") do |cluster|
+    options[:cluster] = cluster
+  end
+
+  opts.on("-m", "--memory", "Memory Flag") do |mem|
+    options[:memory] = mem
+  end
+
   opts.on('--help', 'Displays Help') do
     puts opts
     exit
@@ -323,7 +343,11 @@ def make_proportion_percentage(value)
 
 # create our connection to the redis db
 if !options[:url].nil?
-  redis = Redis.new(:url => options[:url])
+  if options[:cluster].nil?
+    redis = Redis.new(:url => options[:url])
+  else
+    redis = Redis::Cluster.new(nodes: [url], replica: true)
+  end
 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
@@ -335,11 +359,22 @@ def make_proportion_percentage(value)
   if options[:dbnum].nil?
     options[:dbnum] = 0
   end
+  # Build a url for use with connecting in cluster mode
+  url = "redis://#{options[:host]}:#{options[:port]}/#{options[:dbnum]}"
   # 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])
+    if options[:cluster].nil?
+      redis = Redis.new(:host => options[:host], :port => options[:port], :db => options[:dbnum])
+    else
+      redis = Redis::Cluster.new(nodes: [url], replica: true)
+    end
   else
-    redis = Redis.new(:host => options[:host], :port => options[:port], :password => options[:password], :db => options[:dbnum])
+    if options[:cluster].nil?
+      redis = Redis.new(:host => options[:host], :port => options[:port], :password => options[:password], :db => options[:dbnum])
+    else
+      puts "Password not supported with cluster option"
+      exit 1
+    end
   end
 end
 
@@ -348,8 +383,14 @@ def make_proportion_percentage(value)
   options[:sample_size] = 0
 end
 
+# Use the Redis debug command by default
+# TODO: We could try a debug call, and if it fails fall back to memory command
+if options[:memory].nil?
+  options[:memory] = false
+end
+
 # audit our data
-auditor = RedisAudit.new(redis, options[:sample_size])
+auditor = RedisAudit.new(redis, options[:sample_size], options[:memory])
 if !options[:url].nil?
   puts "Auditing #{options[:url]} sampling #{options[:sample_size]} keys"
 else