Trim default metrics (#1086)

Testing has shown that RocksDB and BigQueue metrics has a negative
impact on performance under load.  Disable them by default.


Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

metrics/src/main/java/tech/pegasys/pantheon/metrics/MetricCategory.java

@@ -27,8 +27,9 @@ public enum MetricCategory {
   RPC("rpc"),
   SYNCHRONIZER("synchronizer");
 
+  // Why not BIG_QUEUE and ROCKSDB?  They hurt performance under load.
   public static final Set<MetricCategory> DEFAULT_METRIC_CATEGORIES =
-      EnumSet.allOf(MetricCategory.class);
+      EnumSet.complementOf(EnumSet.of(BIG_QUEUE, ROCKSDB));
 
   private final String name;
   private final boolean pantheonSpecific;

metrics/src/main/java/tech/pegasys/pantheon/metrics/prometheus/MetricsConfiguration.java

@@ -12,12 +12,13 @@
  */
 package tech.pegasys.pantheon.metrics.prometheus;
 
+import static tech.pegasys.pantheon.metrics.MetricCategory.DEFAULT_METRIC_CATEGORIES;
+
 import tech.pegasys.pantheon.metrics.MetricCategory;
 
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.EnumSet;
 import java.util.Objects;
 import java.util.Set;
 
@@ -46,7 +47,7 @@ public class MetricsConfiguration {
     metricsConfiguration.setEnabled(false);
     metricsConfiguration.setPort(DEFAULT_METRICS_PORT);
     metricsConfiguration.setHost(DEFAULT_METRICS_HOST);
-    metricsConfiguration.setMetricCategories(EnumSet.allOf(MetricCategory.class));
+    metricsConfiguration.setMetricCategories(DEFAULT_METRIC_CATEGORIES);
     metricsConfiguration.setPushEnabled(false);
     metricsConfiguration.setPushPort(DEFAULT_METRICS_PUSH_PORT);
     metricsConfiguration.setPushHost(DEFAULT_METRICS_PUSH_HOST);