Not all Description config fields should be compared

lib/mongo/server/description.rb

@@ -124,6 +124,11 @@ class Description
       # @since 2.0.0
       TAGS = 'tags'.freeze
 
+      # Fields to exclude when comparing two descriptions.
+      #
+      # @since 2.0.6
+      EXCLUDE_FOR_COMPARISON = [ 'localTime' ]
+
       # @return [ Address ] address The server's address.
       attr_reader :address
 
@@ -496,7 +501,9 @@ def replica_set_member?
       # @since 2.0.6
       def ==(other)
         return false if self.class != other.class
-        config == other.config
+        !config.keys.empty? && config.keys.all? do |k|
+          config[k] == other.config[k] || EXCLUDE_FOR_COMPARISON.include?(k)
+        end
       end
       alias_method :eql?, :==
     end

spec/mongo/server/description_spec.rb

@@ -22,6 +22,7 @@
       'maxWriteBatchSize' => 1000,
       'maxWireVersion' => 2,
       'minWireVersion' => 0,
+      'localTime' => Time.now,
       'ok' => 1
     }
   end
@@ -691,6 +692,18 @@
 
   describe '#==' do
 
+    let(:description) do
+      described_class.new(address, replica)
+    end
+
+    let(:other) do
+      described_class.new(address, replica.merge('localTime' => 1))
+    end
+
+    it 'excludes certain fields' do
+      expect(description == other).to be(true)
+    end
+
     context 'when the classes do not match' do
 
       let(:description) do