[PIE-1846] Add an experimental flag for disabling timers (#1837)

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

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

@@ -31,6 +31,7 @@ public class MetricsConfiguration {
 
   private static final String DEFAULT_METRICS_PUSH_HOST = "127.0.0.1";
   public static final int DEFAULT_METRICS_PUSH_PORT = 9001;
+  public static final Boolean DEFAULT_TIMERS_ENABLED = true;
 
   private final boolean enabled;
   private final int port;
@@ -42,6 +43,7 @@ public class MetricsConfiguration {
   private final int pushInterval;
   private final String prometheusJob;
   private final List<String> hostsWhitelist;
+  private final boolean timersEnabled;
 
   public static Builder builder() {
     return new Builder();
@@ -57,7 +59,8 @@ public class MetricsConfiguration {
       final String pushHost,
       final int pushInterval,
       final String prometheusJob,
-      final List<String> hostsWhitelist) {
+      final List<String> hostsWhitelist,
+      final boolean timersEnabled) {
     this.enabled = enabled;
     this.port = port;
     this.host = host;
@@ -68,6 +71,7 @@ public class MetricsConfiguration {
     this.pushInterval = pushInterval;
     this.prometheusJob = prometheusJob;
     this.hostsWhitelist = hostsWhitelist;
+    this.timersEnabled = timersEnabled;
   }
 
   public boolean isEnabled() {
@@ -110,6 +114,10 @@ public class MetricsConfiguration {
     return Collections.unmodifiableCollection(this.hostsWhitelist);
   }
 
+  public boolean isTimersEnabled() {
+    return timersEnabled;
+  }
+
   @Override
   public String toString() {
     return MoreObjects.toStringHelper(this)
@@ -173,6 +181,7 @@ public class MetricsConfiguration {
     private int pushInterval = 15;
     private String prometheusJob = "pantheon-client";
     private List<String> hostsWhitelist = Arrays.asList("localhost", "127.0.0.1");
+    private boolean timersEnabled = DEFAULT_TIMERS_ENABLED;
 
     private Builder() {}
 
@@ -226,6 +235,11 @@ public class MetricsConfiguration {
       return this;
     }
 
+    public Builder timersEnabled(final boolean timersEnabled) {
+      this.timersEnabled = timersEnabled;
+      return this;
+    }
+
     public MetricsConfiguration build() {
       return new MetricsConfiguration(
           enabled,
@@ -237,7 +251,8 @@ public class MetricsConfiguration {
           pushHost,
           pushInterval,
           prometheusJob,
-          hostsWhitelist);
+          hostsWhitelist,
+          timersEnabled);
     }
   }
 }

metrics/core/src/main/java/tech/pegasys/pantheon/metrics/prometheus/PrometheusMetricsSystem.java

@@ -58,9 +58,12 @@ public class PrometheusMetricsSystem implements MetricsSystem {
       cachedTimers = new ConcurrentHashMap<>();
 
   private final Set<MetricCategory> enabledCategories;
+  private final boolean timersEnabled;
 
-  PrometheusMetricsSystem(final Set<MetricCategory> enabledCategories) {
+  PrometheusMetricsSystem(
+      final Set<MetricCategory> enabledCategories, final boolean timersEnabled) {
     this.enabledCategories = ImmutableSet.copyOf(enabledCategories);
+    this.timersEnabled = timersEnabled;
   }
 
   public static MetricsSystem init(final MetricsConfiguration metricsConfiguration) {
@@ -68,7 +71,8 @@ public class PrometheusMetricsSystem implements MetricsSystem {
       return new NoOpMetricsSystem();
     }
     final PrometheusMetricsSystem metricsSystem =
-        new PrometheusMetricsSystem(metricsConfiguration.getMetricCategories());
+        new PrometheusMetricsSystem(
+            metricsConfiguration.getMetricCategories(), metricsConfiguration.isTimersEnabled());
     if (metricsSystem.isCategoryEnabled(StandardMetricCategory.PROCESS)) {
       metricsSystem.collectors.put(
           StandardMetricCategory.PROCESS,
@@ -117,7 +121,7 @@ public class PrometheusMetricsSystem implements MetricsSystem {
     return cachedTimers.computeIfAbsent(
         metricName,
         (k) -> {
-          if (isCategoryEnabled(category)) {
+          if (timersEnabled && isCategoryEnabled(category)) {
             final Summary summary =
                 Summary.build(metricName, help)
                     .quantile(0.2, 0.02)

metrics/core/src/test/java/tech/pegasys/pantheon/metrics/prometheus/PrometheusMetricsSystemTest.java

@@ -45,7 +45,7 @@ public class PrometheusMetricsSystemTest {
           .thenComparing((o1, o2) -> o1.getLabels().equals(o2.getLabels()) ? 0 : 1);
 
   private final MetricsSystem metricsSystem =
-      new PrometheusMetricsSystem(DEFAULT_METRIC_CATEGORIES);
+      new PrometheusMetricsSystem(DEFAULT_METRIC_CATEGORIES, true);
 
   @Test
   public void shouldCreateObservationFromCounter() {
@@ -155,6 +155,19 @@ public class PrometheusMetricsSystemTest {
             new Observation(RPC, "request", null, asList("method", "count")));
   }
 
+  @Test
+  public void shouldNotCreateObservationsFromTimerWhenTimersDisabled() {
+    final MetricsSystem metricsSystem =
+        new PrometheusMetricsSystem(DEFAULT_METRIC_CATEGORIES, false);
+    final LabelledMetric<OperationTimer> timer =
+        metricsSystem.createLabelledTimer(RPC, "request", "Some help", "methodName");
+
+    //noinspection EmptyTryBlock
+    try (final TimingContext ignored = timer.labels("method").startTimer()) {}
+
+    assertThat(metricsSystem.streamObservations()).isEmpty();
+  }
+
   @Test
   public void shouldCreateObservationFromGauge() {
     metricsSystem.createGauge(JVM, "myValue", "Help", () -> 7d);

pantheon/src/main/java/tech/pegasys/pantheon/cli/PantheonCommand.java

@@ -41,6 +41,7 @@ import tech.pegasys.pantheon.cli.custom.JsonRPCWhitelistHostsProperty;
 import tech.pegasys.pantheon.cli.custom.RpcAuthFileValidator;
 import tech.pegasys.pantheon.cli.error.PantheonExceptionHandler;
 import tech.pegasys.pantheon.cli.options.EthProtocolOptions;
+import tech.pegasys.pantheon.cli.options.MetricsCLIOptions;
 import tech.pegasys.pantheon.cli.options.NetworkingOptions;
 import tech.pegasys.pantheon.cli.options.RocksDBOptions;
 import tech.pegasys.pantheon.cli.options.SynchronizerOptions;
@@ -160,6 +161,7 @@ public class PantheonCommand implements DefaultCommandValues, Runnable {
   final NetworkingOptions networkingOptions = NetworkingOptions.create();
   final SynchronizerOptions synchronizerOptions = SynchronizerOptions.create();
   final EthProtocolOptions ethProtocolOptions = EthProtocolOptions.create();
+  final MetricsCLIOptions metricsCLIOptions = MetricsCLIOptions.create();
   final RocksDBOptions rocksDBOptions = RocksDBOptions.create();
   final TransactionPoolOptions transactionPoolOptions = TransactionPoolOptions.create();
   private final RunnerBuilder runnerBuilder;
@@ -715,19 +717,18 @@ public class PantheonCommand implements DefaultCommandValues, Runnable {
 
   private PantheonCommand handleUnstableOptions() {
     // Add unstable options
-    UnstableOptionsSubCommand.createUnstableOptions(
-        commandLine,
-        ImmutableMap.of(
-            "P2P Network",
-            networkingOptions,
-            "Synchronizer",
-            synchronizerOptions,
-            "RocksDB",
-            rocksDBOptions,
-            "Ethereum Wire Protocol",
-            ethProtocolOptions,
-            "TransactionPool",
-            transactionPoolOptions));
+    final ImmutableMap.Builder<String, Object> unstableOptionsBuild = ImmutableMap.builder();
+    final ImmutableMap<String, Object> unstableOptions =
+        unstableOptionsBuild
+            .put("Ethereum Wire Protocol", ethProtocolOptions)
+            .put("Metrics", metricsCLIOptions)
+            .put("P2P Network", networkingOptions)
+            .put("RocksDB", rocksDBOptions)
+            .put("Synchronizer", synchronizerOptions)
+            .put("TransactionPool", transactionPoolOptions)
+            .build();
+
+    UnstableOptionsSubCommand.createUnstableOptions(commandLine, unstableOptions);
     return this;
   }
 
@@ -1006,7 +1007,8 @@ public class PantheonCommand implements DefaultCommandValues, Runnable {
             "--metrics-push-interval",
             "--metrics-push-prometheus-job"));
 
-    return MetricsConfiguration.builder()
+    return metricsCLIOptions
+        .toDomainObject()
         .enabled(isMetricsEnabled)
         .host(metricsHost)
         .port(metricsPort)

pantheon/src/main/java/tech/pegasys/pantheon/cli/options/MetricsCLIOptions.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed 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 tech.pegasys.pantheon.cli.options;
+
+import tech.pegasys.pantheon.metrics.prometheus.MetricsConfiguration;
+
+import java.util.Arrays;
+import java.util.List;
+
+import picocli.CommandLine;
+
+public class MetricsCLIOptions implements CLIOptions<MetricsConfiguration.Builder> {
+  private static final String TIMERS_ENABLED_FLAG = "--Xmetrics-timers-enabled";
+
+  @CommandLine.Option(
+      names = TIMERS_ENABLED_FLAG,
+      hidden = true,
+      defaultValue = "true",
+      description = "Whether to enable timer metrics (default: ${DEFAULT-VALUE}).")
+  private Boolean timersEnabled = MetricsConfiguration.DEFAULT_TIMERS_ENABLED;
+
+  private MetricsCLIOptions() {}
+
+  public static MetricsCLIOptions create() {
+    return new MetricsCLIOptions();
+  }
+
+  public static MetricsCLIOptions fromConfiguration(final MetricsConfiguration config) {
+    final MetricsCLIOptions metricsOptions = create();
+    metricsOptions.timersEnabled = config.isTimersEnabled();
+    return metricsOptions;
+  }
+
+  @Override
+  public MetricsConfiguration.Builder toDomainObject() {
+    return MetricsConfiguration.builder().timersEnabled(timersEnabled);
+  }
+
+  @Override
+  public List<String> getCLIOptions() {
+    return Arrays.asList(TIMERS_ENABLED_FLAG + "=" + timersEnabled.toString());
+  }
+}

pantheon/src/test/java/tech/pegasys/pantheon/cli/CommandTestAbstract.java

@@ -25,6 +25,7 @@ import tech.pegasys.pantheon.Runner;
 import tech.pegasys.pantheon.RunnerBuilder;
 import tech.pegasys.pantheon.cli.config.EthNetworkConfig;
 import tech.pegasys.pantheon.cli.options.EthProtocolOptions;
+import tech.pegasys.pantheon.cli.options.MetricsCLIOptions;
 import tech.pegasys.pantheon.cli.options.NetworkingOptions;
 import tech.pegasys.pantheon.cli.options.RocksDBOptions;
 import tech.pegasys.pantheon.cli.options.SynchronizerOptions;
@@ -288,5 +289,9 @@ public abstract class CommandTestAbstract {
     public TransactionPoolOptions getTransactionPoolOptions() {
       return transactionPoolOptions;
     }
+
+    public MetricsCLIOptions getMetricsCLIOptions() {
+      return metricsCLIOptions;
+    }
   }
 }

pantheon/src/test/java/tech/pegasys/pantheon/cli/options/MetricsCLIOptionsTest.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed 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 tech.pegasys.pantheon.cli.options;
+
+import tech.pegasys.pantheon.metrics.prometheus.MetricsConfiguration;
+
+public class MetricsCLIOptionsTest
+    extends AbstractCLIOptionsTest<MetricsConfiguration.Builder, MetricsCLIOptions> {
+
+  @Override
+  MetricsConfiguration.Builder createDefaultDomainObject() {
+    return MetricsConfiguration.builder();
+  }
+
+  @Override
+  MetricsConfiguration.Builder createCustomizedDomainObject() {
+    return MetricsConfiguration.builder()
+        .timersEnabled(!MetricsConfiguration.DEFAULT_TIMERS_ENABLED);
+  }
+
+  @Override
+  MetricsCLIOptions optionsFromDomainObject(final MetricsConfiguration.Builder domainObject) {
+    return MetricsCLIOptions.fromConfiguration(domainObject.build());
+  }
+
+  @Override
+  MetricsCLIOptions getOptionsFromPantheonCommand(final TestPantheonCommand pantheonCommand) {
+    return pantheonCommand.getMetricsCLIOptions();
+  }
+}