Lower thread count for improved stability. (#98)

By reducing thread count to 10x CPUs we found that on the same instances we only lose about 4% of throughput but seem more than 40% improvement in latency. More importantly the variation between runs drops significantly. This variation was greater than 10% on Java 11 and 3% on Java 8. When lowered to 10x threads we see closer to 1% variation for both Java 11 and 8.

geode-benchmarks/src/main/java/org/apache/geode/benchmark/tests/GeodeBenchmark.java

@@ -34,7 +34,7 @@ public class GeodeBenchmark {
   /**
    * Number of threads to run benchmark.
    */
-  private static final int THREADS = Runtime.getRuntime().availableProcessors() * 16;
+  private static final int THREADS = Runtime.getRuntime().availableProcessors() * 10;
 
 
   public static TestConfig createConfig() {