[overhead] - Add network average read/write to output (#3872)

* add average network read/write to the output results.

* guard against div/zero

benchmark-overhead/src/test/java/io/opentelemetry/results/AppPerfResults.java

@@ -21,6 +21,8 @@ public class AppPerfResults {
   final float maxThreadContextSwitchRate;
   final long startupDurationMs;
   final long peakThreadCount;
+  final long averageNetworkRead;
+  final long averageNetworkWrite;
 
   private AppPerfResults(Builder builder) {
     this.agent = builder.agent;
@@ -35,6 +37,8 @@ public class AppPerfResults {
     this.maxThreadContextSwitchRate = builder.maxThreadContextSwitchRate;
     this.startupDurationMs = builder.startupDurationMs;
     this.peakThreadCount = builder.peakThreadCount;
+    this.averageNetworkRead = builder.averageNetworkRead;
+    this.averageNetworkWrite = builder.averageNetworkWrite;
   }
 
   double getTotalAllocatedMB() {
@@ -61,6 +65,8 @@ public class AppPerfResults {
     private MinMax heapUsed;
     private float maxThreadContextSwitchRate;
     private long peakThreadCount;
+    public long averageNetworkRead;
+    public long averageNetworkWrite;
 
     AppPerfResults build() {
       return new AppPerfResults(this);
@@ -125,6 +131,16 @@ public class AppPerfResults {
       this.peakThreadCount = peakThreadCount;
       return this;
     }
+
+    Builder averageNetworkRead(long averageNetworkRead){
+      this.averageNetworkRead = averageNetworkRead;
+      return this;
+    }
+
+    Builder averageNetworkWrite(long averageNetworkWrite){
+      this.averageNetworkWrite = averageNetworkWrite;
+      return this;
+    }
   }
 
   public static class MinMax {

benchmark-overhead/src/test/java/io/opentelemetry/results/CsvPersister.java

@@ -39,6 +39,8 @@ class CsvPersister implements ResultsPersister {
       sb.append(",").append(result.iterationP95);
       sb.append(",").append(result.requestAvg);
       sb.append(",").append(result.requestP95);
+      sb.append(",").append(result.averageNetworkRead);
+      sb.append(",").append(result.averageNetworkWrite);
       sb.append(",").append(result.peakThreadCount);
     });
     sb.append("\n");
@@ -79,6 +81,8 @@ class CsvPersister implements ResultsPersister {
       sb.append(",").append(agent).append(":iterationP95");
       sb.append(",").append(agent).append(":requestAvg");
       sb.append(",").append(agent).append(":requestP95");
+      sb.append(",").append(agent).append(":netReadAvg");
+      sb.append(",").append(agent).append(":netWriteAvg");
       sb.append(",").append(agent).append(":peakThreadCount");
     });
     sb.append("\n");

benchmark-overhead/src/test/java/io/opentelemetry/results/PrintStreamPersister.java

@@ -41,6 +41,8 @@ class PrintStreamPersister implements ResultsPersister {
     display(sorted, "Req. p95", res -> format(res.requestP95));
     display(sorted, "Iter. mean", res -> format(res.iterationAvg));
     display(sorted, "Iter. p95", res -> format(res.iterationP95));
+    display(sorted, "Net read avg (bps)", res -> format(res.averageNetworkRead));
+    display(sorted, "Net write avg (bps)", res -> format(res.averageNetworkWrite));
     display(sorted, "Peak threads", res -> String.valueOf(res.peakThreadCount));
   }
 

benchmark-overhead/src/test/java/io/opentelemetry/results/ResultsCollector.java

@@ -75,7 +75,17 @@ public class ResultsCollector {
         .totalAllocated(readTotalAllocated(jfrFile))
         .heapUsed(readHeapUsed(jfrFile))
         .maxThreadContextSwitchRate(readMaxThreadContextSwitchRate(jfrFile))
-        .peakThreadCount(readPeakThreadCount(jfrFile));
+        .peakThreadCount(readPeakThreadCount(jfrFile))
+        .averageNetworkRead(computeAverageNetworkRead(jfrFile))
+        .averageNetworkWrite(computeAverageNetworkWrite(jfrFile));
+  }
+
+  private long computeAverageNetworkRead(Path jfrFile) throws IOException {
+    return JFRUtils.findAverageLong(jfrFile, "jdk.NetworkUtilization", "readRate");
+  }
+
+  private long computeAverageNetworkWrite(Path jfrFile) throws IOException {
+    return JFRUtils.findAverageLong(jfrFile, "jdk.NetworkUtilization", "writeRate");
   }
 
   private long readPeakThreadCount(Path jfrFile) throws IOException {

benchmark-overhead/src/test/java/io/opentelemetry/util/JFRUtils.java

@@ -34,6 +34,12 @@ public class JFRUtils {
     });
   }
 
+  public static long findAverageLong(Path jfrFile, String eventName, String valueKey) throws IOException {
+    return reduce(jfrFile, eventName, valueKey,
+        new AverageSupport(),
+        AverageSupport::add).average();
+  }
+
   private static <T, V> T reduce(Path jfrFile, String eventName,
       String valueKey, T initial, BiFunction<T,V,T> reducer) throws IOException {
     RecordingFile recordingFile = new RecordingFile(jfrFile);
@@ -47,4 +53,18 @@ public class JFRUtils {
     }
     return result;
   }
+
+  static class AverageSupport {
+    long count;
+    long total;
+    AverageSupport add(long value){
+      count++;
+      total += value;
+      return this;
+    }
+    long average(){
+      if(count == 0) return -1;
+      return total/count;
+    }
+  }
 }