Merge 52692569-warn-if-memory-close-to-default to master

Glyn Normington · Glyn Normington · commit e76b65f861f9 · 2013-07-08T16:58:19.000+01:00
[Completes #52692569]
diff --git a/lib/java_buildpack/jre/memory/stack_memory_bucket.rb b/lib/java_buildpack/jre/memory/stack_memory_bucket.rb
@@ -33,20 +33,29 @@ class StackMemoryBucket < MemoryBucket
     # @param [Numeric] total_memory the total virtual memory size of the operating system process in KB
     def initialize(weighting, size, total_memory)
       super('stack', weighting, size, false, total_memory)
+      @weighting = weighting
+      @total_memory = total_memory
       set_size(DEFAULT_STACK_SIZE) unless size
     end
 
     # Returns the excess memory in this memory bucket.
     #
     # @return [Numeric] the excess memory in KB
     def excess
-      if default_size
-        size ? default_size * ((size - DEFAULT_STACK_SIZE) / DEFAULT_STACK_SIZE) : 0
+      if @total_memory
+        size ? @total_memory * @weighting * ((size - DEFAULT_STACK_SIZE) / DEFAULT_STACK_SIZE) : 0
       else
         MemorySize.ZERO
       end
     end
 
+    # Returns the default stack size.
+    #
+    # @return [MemorySize, nil] the default memory size or nil if there is no default
+    def default_size
+      DEFAULT_STACK_SIZE
+    end
+
     private
 
     DEFAULT_STACK_SIZE = MemorySize.new('1024K') # 1 MB
diff --git a/lib/java_buildpack/jre/memory/weight_balancing_memory_heuristic.rb b/lib/java_buildpack/jre/memory/weight_balancing_memory_heuristic.rb
@@ -58,6 +58,7 @@ def resolve
 
       balance_buckets(@sizes, buckets, memory_limit)
       issue_memory_wastage_warning(buckets) if memory_limit
+      issue_close_to_default_warnings(buckets, @heuristics, memory_limit)
 
       buckets.map { |type, bucket| "#{@java_opts[type]}#{bucket.size}" if bucket.size && @java_opts.has_key?(type) }.compact
     end
@@ -66,6 +67,8 @@ def resolve
 
     NATIVE_MEMORY_WARNING_FACTOR = 3
 
+    CLOSE_TO_DEFAULT_FACTOR = 0.1
+
     def balance_buckets(sizes, buckets, memory_limit)
       total_excess = MemorySize.ZERO
       total_adjustable_weighting = 0
@@ -122,6 +125,22 @@ def validate(type, expected, actual)
       end
     end
 
+    def issue_close_to_default_warnings(buckets, heuristics, memory_limit)
+      # Check each specified memory size to see if it is close to the default.
+      buckets.each do |type, bucket|
+        if @sizes[type]
+          default_size = bucket.default_size
+          actual_size = bucket.size
+          if default_size != MemorySize.ZERO
+            factor = ((actual_size - default_size) / default_size).abs
+          end
+          if (default_size == MemorySize.ZERO && actual_size == MemorySize.ZERO) || factor < CLOSE_TO_DEFAULT_FACTOR
+            $stderr.puts "-----> WARNING: the configured value #{actual_size} of memory size #{type} is close to the default value #{default_size}. Consider deleting the configured value and taking the default."
+          end
+        end
+      end
+    end
+
   end
 
 end
diff --git a/spec/java_buildpack/jre/memory/weight_balancing_memory_heuristic_spec.rb b/spec/java_buildpack/jre/memory/weight_balancing_memory_heuristic_spec.rb
@@ -183,7 +183,29 @@ module JavaBuildpack::Jre
         expect(output).to include('-Xss2M')
         expect($stderr.string).to match(/WARNING:/)
       end
+    end
+
+    it 'should issue a warning when the specified stack size is close to the default' do
+      with_memory_limit('4096m') do
+        WeightBalancingMemoryHeuristic.new({'stack' => '1025k'}, TEST_WEIGHTINGS, VALID_SIZES, VALID_HEURISTICS, JAVA_OPTS).resolve
+        expect($stderr.string).to match(/WARNING:.*close to the default/)
+      end
+    end
+
+    it 'should issue a warning when the specified maximum heap size is close to the default' do
+      with_memory_limit('4096m') do
+        WeightBalancingMemoryHeuristic.new({'heap' => '2049m'}, TEST_WEIGHTINGS, VALID_SIZES, VALID_HEURISTICS, JAVA_OPTS).resolve
+        expect($stderr.string).to match(/WARNING:.*close to the default/)
       end
+    end
+
+   it 'should issue a warning when the specified maximum permgen size is close to the default' do
+      with_memory_limit('4096m') do
+        WeightBalancingMemoryHeuristic.new({'permgen' => '1339m'}, TEST_WEIGHTINGS, VALID_SIZES, VALID_HEURISTICS, JAVA_OPTS).resolve
+        expect($stderr.string).to match(/WARNING:.*close to the default/)
+      end
+    end
+
 
     it 'should fail when the specified maximum memory is larger than the total memory size' do
       with_memory_limit('4096m') do
