title: Has the StackExchange Redis connection config changed?
body: <p>I have been using the following to connect to Redis without issue until today, now I have to explicitly state provide a database parameter because of this:</p>
  
  <pre><code>ArgumentOutOfRangeException 
  Specified argument was out of the range of valid values. Parameter name: db at StackExchange.Redis.ConnectionMultiplexer.GetDatabase(Int32 db, Object  asyncState) at MyServer.MyClass..cctor()  
  </code></pre>
  
  <p>This is the config I have been using:</p>
  
  <pre><code> private static Lazy&lt;ConnectionMultiplexer&gt; MyConnection = new   Lazy&lt;ConnectionMultiplexer&gt;(() =&gt;
      {
          return ConnectionMultiplexer.Connect(MyRedisConnString);
      });
  
      public static ConnectionMultiplexer ConnGer
      {
          get
          {
              return MyConnection.Value;
          }
      }
  </code></pre>
  
  <p>and at class level: </p>
  
  <pre><code>private static readonly IDatabase RedisDb = RedisConfig.ConnGer.GetDatabase();
  </code></pre>
  
  <p>Providing the db parameter thus:
      RedisConfig.ConnGer.GetDatabase(0);
   fixed the error of course; more of a concern is  whether there have been any seeming breaking changes recently as my class libraries are littered with Redis!</p>
  
  <p>UPDATE
  After thinking I had resolved the issue, for no apparent reason the ConnectionMultiplexer started failing again with the above config. I tried <code>defaultDatabase=0</code> in the string and also tried as a Configuration.Option and got this error: </p>
  
  <p><code>Exception type: ArgumentException 
      Exception message: Keyword 'defaultDatabase' is not supported
     at StackExchange.Redis.ConfigurationOptions.OptionKeys.Unknown(String key)
     at StackExchange.Redis.ConfigurationOptions.DoParse(String configuration, Boolean ignoreUnknown)
     at StackExchange.Redis.ConnectionMultiplexer.CreateMultiplexer(Object configuration)
     at StackExchange.Redis.ConnectionMultiplexer.ConnectImpl(Func 1 multiplexerFactory, TextWriter log)
     at System.Lazy</code>1.CreateValue()`</p>
  
  <p>and with the ConfigOption mode:</p>
  
  <p><code>Exception type: TypeInitializationException 
  Method not found: 'Void StackExchange.Redis.ConfigurationOptions.set_DefaultDatabase(System.Nullable 1&lt;Int32&gt;)'.</code></p>
  
  <p>I also removed the System.Lazy part of the config too, same errors.</p>
  
  <p>Putting the 0 value in as a GetDatabase() parameter stopped the error for now; the concern remains that this doesn't match the documented implementation.</p>