HDDS-15. Add memory profiler support to Genesis. Contributed by Anu Engineer.

hadoop-ozone/tools/src/main/java/org/apache/hadoop/ozone/genesis/Genesis.java

@@ -42,9 +42,12 @@ public final class Genesis {
         .include(BenchMarkMetadataStoreReads.class.getSimpleName())
         .include(BenchMarkMetadataStoreWrites.class.getSimpleName())
         .include(BenchMarkDatanodeDispatcher.class.getSimpleName())
-        .include(BenchMarkRocksDbStore.class.getSimpleName())
+// Commenting this test out, till we support either a command line or a config
+        // file based ability to run tests.
+//        .include(BenchMarkRocksDbStore.class.getSimpleName())
         .warmupIterations(5)
         .measurementIterations(20)
+        .addProfiler(GenesisMemoryProfiler.class)
         .shouldDoGC(true)
         .forks(1)
         .build();
@@ -52,3 +55,5 @@ public final class Genesis {
     new Runner(opt).run();
   }
 }
+
+

hadoop-ozone/tools/src/main/java/org/apache/hadoop/ozone/genesis/GenesisMemoryProfiler.java

@@ -0,0 +1,59 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with this
+ * work for additional information regarding copyright ownership.  The ASF
+ * licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ *
+ */
+
+package org.apache.hadoop.ozone.genesis;
+
+import org.openjdk.jmh.infra.BenchmarkParams;
+import org.openjdk.jmh.infra.IterationParams;
+import org.openjdk.jmh.profile.InternalProfiler;
+import org.openjdk.jmh.results.AggregationPolicy;
+import org.openjdk.jmh.results.IterationResult;
+import org.openjdk.jmh.results.Result;
+import org.openjdk.jmh.results.ScalarResult;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+/**
+ * Max memory profiler.
+ */
+public class GenesisMemoryProfiler implements InternalProfiler {
+  @Override
+  public void beforeIteration(BenchmarkParams benchmarkParams,
+      IterationParams iterationParams) {
+
+  }
+
+  @Override
+  public Collection<? extends Result> afterIteration(BenchmarkParams
+      benchmarkParams, IterationParams iterationParams, IterationResult
+      result) {
+    long totalHeap = Runtime.getRuntime().totalMemory();
+
+    Collection<ScalarResult> samples = new ArrayList<>();
+    samples.add(new ScalarResult("Max heap", totalHeap, "bytes",
+        AggregationPolicy.MAX));
+    return samples;
+  }
+
+  @Override
+  public String getDescription() {
+    return "Genesis Memory Profiler. Computes Max Memory used by a test.";
+  }
+}
+