Prober metrics collection (#222)

* Added MetricsHandler and Clock to ProbingSequences

* Minor fixes after rebase onto master

* Added metrics gathering to ProbingSequences

* Added testing of MetricsCollector method calls in ProbingSequenceTest

* Added tests on latency recording to ProbingSequenceTest

* Added response name as label to metrics

prober/build.gradle

@@ -25,6 +25,7 @@ dependencies {
     compile deps['com.google.dagger:dagger']
     compile deps['com.google.flogger:flogger']
     compile deps['com.google.guava:guava']
+    compile deps['com.google.monitoring-client:metrics']
     compile deps['io.netty:netty-buffer']
     compile deps['io.netty:netty-codec-http']
     compile deps['io.netty:netty-codec']
@@ -41,10 +42,12 @@ dependencies {
     runtime deps['com.google.auto.value:auto-value']
     runtime deps['io.netty:netty-tcnative-boringssl-static']
 
+    testCompile deps['com.google.monitoring-client:contrib']
     testCompile deps['com.google.truth:truth']
     testCompile deps['junit:junit']
     testCompile deps['org.mockito:mockito-core']
     testCompile project(':third_party')
+    testCompile project(path: ':core', configuration: 'testRuntime')
 
     // Include auto-value in compile until nebula-lint understands
     // annotationProcessor

prober/src/main/java/google/registry/monitoring/blackbox/ProberModule.java

@@ -21,6 +21,8 @@ import google.registry.monitoring.blackbox.connection.ProbingAction;
 import google.registry.monitoring.blackbox.modules.CertificateModule;
 import google.registry.monitoring.blackbox.modules.EppModule;
 import google.registry.monitoring.blackbox.modules.WebWhoisModule;
+import google.registry.util.Clock;
+import google.registry.util.SystemClock;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.EventLoopGroup;
@@ -54,6 +56,13 @@ public class ProberModule {
     return OpenSsl.isAvailable() ? SslProvider.OPENSSL : SslProvider.JDK;
   }
 
+  /** {@link Provides} one global {@link Clock} shared by each {@link ProbingSequence}. */
+  @Provides
+  @Singleton
+  static Clock provideClock() {
+    return new SystemClock();
+  }
+
   /** {@link Provides} one global {@link EventLoopGroup} shared by each {@link ProbingSequence}. */
   @Provides
   @Singleton

prober/src/main/java/google/registry/monitoring/blackbox/ProbingSequence.java

@@ -16,9 +16,12 @@ package google.registry.monitoring.blackbox;
 
 import com.google.common.flogger.FluentLogger;
 import google.registry.monitoring.blackbox.connection.ProbingAction;
+import google.registry.monitoring.blackbox.exceptions.FailureException;
 import google.registry.monitoring.blackbox.exceptions.UnrecoverableStateException;
+import google.registry.monitoring.blackbox.metrics.MetricsCollector;
 import google.registry.monitoring.blackbox.tokens.Token;
 import google.registry.util.CircularList;
+import google.registry.util.Clock;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.AbstractChannel;
 import io.netty.channel.ChannelFuture;
@@ -45,6 +48,12 @@ public class ProbingSequence extends CircularList<ProbingStep> {
 
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
+  /** Shared {@link MetricsCollector} used to record metrics on any step performed. */
+  private MetricsCollector metrics;
+
+  /** Shared {@link Clock} used to record latency on any step performed. */
+  private Clock clock;
+
   /** Each {@link ProbingSequence} requires a start token to begin running. */
   private Token startToken;
 
@@ -57,9 +66,16 @@ public class ProbingSequence extends CircularList<ProbingStep> {
   /** {@link ProbingSequence} object that represents first step in the sequence. */
   private ProbingSequence first;
 
-  /** Standard constructor for {@link ProbingSequence} in the list that assigns value and token. */
-  private ProbingSequence(ProbingStep value, Token startToken) {
+  /**
+   * Standard constructor for first {@link ProbingSequence} in the list that assigns value and
+   * token.
+   */
+  private ProbingSequence(
+      ProbingStep value, MetricsCollector metrics, Clock clock, Token startToken) {
+
     super(value);
+    this.metrics = metrics;
+    this.clock = clock;
     this.startToken = startToken;
   }
 
@@ -95,6 +111,8 @@ public class ProbingSequence extends CircularList<ProbingStep> {
    *     get().generateAction}.
    */
   private void runStep(Token token) {
+    long start = clock.nowUtc().getMillis();
+
     ProbingAction currentAction;
     ChannelFuture future;
 
@@ -108,12 +126,28 @@ public class ProbingSequence extends CircularList<ProbingStep> {
     } catch (UnrecoverableStateException e) {
       // On an UnrecoverableStateException, terminate the sequence.
       logger.atSevere().withCause(e).log("Unrecoverable error in generating or calling action.");
+
+      // Records gathered metrics.
+      metrics.recordResult(
+          get().protocol().name(),
+          get().messageTemplate().name(),
+          get().messageTemplate().responseName(),
+          MetricsCollector.ResponseType.ERROR,
+          clock.nowUtc().getMillis() - start);
       return;
 
     } catch (Exception e) {
       // On any other type of error, restart the sequence at the very first step.
       logger.atWarning().withCause(e).log("Error in generating or calling action.");
 
+      // Records gathered metrics.
+      metrics.recordResult(
+          get().protocol().name(),
+          get().messageTemplate().name(),
+          get().messageTemplate().responseName(),
+          MetricsCollector.ResponseType.ERROR,
+          clock.nowUtc().getMillis() - start);
+
       // Restart the sequence at the very first step.
       restartSequence();
       return;
@@ -125,10 +159,34 @@ public class ProbingSequence extends CircularList<ProbingStep> {
             // On a successful result, we log as a successful step, and note a success.
             logger.atInfo().log(String.format("Successfully completed Probing Step: %s", this));
 
+            // Records gathered metrics.
+            metrics.recordResult(
+                get().protocol().name(),
+                get().messageTemplate().name(),
+                get().messageTemplate().responseName(),
+                MetricsCollector.ResponseType.SUCCESS,
+                clock.nowUtc().getMillis() - start);
           } else {
             // On a failed result, we log the failure and note either a failure or error.
             logger.atSevere().withCause(f.cause()).log("Did not result in future success");
 
+            // Records gathered metrics as either FAILURE or ERROR depending on future's cause.
+            if (f.cause() instanceof FailureException) {
+              metrics.recordResult(
+                  get().protocol().name(),
+                  get().messageTemplate().name(),
+                  get().messageTemplate().responseName(),
+                  MetricsCollector.ResponseType.FAILURE,
+                  clock.nowUtc().getMillis() - start);
+            } else {
+              metrics.recordResult(
+                  get().protocol().name(),
+                  get().messageTemplate().name(),
+                  get().messageTemplate().responseName(),
+                  MetricsCollector.ResponseType.ERROR,
+                  clock.nowUtc().getMillis() - start);
+            }
+
             // If not unrecoverable, we restart the sequence.
             if (!(f.cause() instanceof UnrecoverableStateException)) {
               restartSequence();
@@ -181,12 +239,18 @@ public class ProbingSequence extends CircularList<ProbingStep> {
 
     private Token startToken;
 
+    private MetricsCollector metrics;
+
+    private Clock clock;
+
     /**
      * This Builder must also be supplied with a {@link Token} to construct a {@link
      * ProbingSequence}.
      */
-    public Builder(Token startToken) {
+    public Builder(Token startToken, MetricsCollector metrics, Clock clock) {
       this.startToken = startToken;
+      this.metrics = metrics;
+      this.clock = clock;
     }
 
     /** We take special note of the first repeated step. */
@@ -205,7 +269,7 @@ public class ProbingSequence extends CircularList<ProbingStep> {
 
     @Override
     protected ProbingSequence create(ProbingStep value) {
-      return new ProbingSequence(value, startToken);
+      return new ProbingSequence(value, metrics, clock, startToken);
     }
 
     /**

prober/src/main/java/google/registry/monitoring/blackbox/messages/EppRequestMessage.java

@@ -44,6 +44,12 @@ import java.util.function.BiFunction;
  */
 public class EppRequestMessage extends EppMessage implements OutboundMessageType {
 
+  /**
+   * String that describes the type of EppRequestMessage: hello, login, create, check, delete,
+   * logout.
+   */
+  private String name;
+
   /** Corresponding {@link EppResponseMessage} that we expect to receive on a successful request. */
   private EppResponseMessage expectedResponse;
 
@@ -60,10 +66,12 @@ public class EppRequestMessage extends EppMessage implements OutboundMessageType
    * Private constructor for {@link EppRequestMessage} that its subclasses use for instantiation.
    */
   public EppRequestMessage(
+      String name,
       EppResponseMessage expectedResponse,
       String template,
       BiFunction<String, String, Map<String, String>> getReplacements) {
 
+    this.name = name;
     this.expectedResponse = expectedResponse;
     this.template = template;
     this.getReplacements = getReplacements;
@@ -125,8 +133,18 @@ public class EppRequestMessage extends EppMessage implements OutboundMessageType
     return buf;
   }
 
-  /** */
+  /** Returns the {@link EppResponseMessage} we expect. */
   public EppResponseMessage getExpectedResponse() {
     return expectedResponse;
   }
+
+  @Override
+  public String name() {
+    return name;
+  }
+
+  @Override
+  public String responseName() {
+    return expectedResponse.name();
+  }
 }

prober/src/main/java/google/registry/monitoring/blackbox/messages/HttpRequestMessage.java

@@ -79,7 +79,12 @@ public class HttpRequestMessage extends DefaultFullHttpRequest implements Outbou
   }
 
   @Override
-  public String toString() {
+  public String name() {
     return String.format("Http(s) Request on: %s", headers().get("host"));
   }
+
+  @Override
+  public String responseName() {
+    return "Http Response";
+  }
 }

prober/src/main/java/google/registry/monitoring/blackbox/messages/OutboundMessageType.java

@@ -30,8 +30,15 @@ public interface OutboundMessageType {
 
   /**
    * Necessary to inform metrics collector what kind of message is sent down {@link
-   * io.netty.channel.ChannelPipeline}
+   * io.netty.channel.ChannelPipeline}. Not equivalent to toString, as to different instances will
+   * have the same name if they perform the same action.
    */
-  @Override
-  String toString();
+  String name();
+
+  /**
+   * Necessary to inform metrics collector what kind of message is sent inbound {@link
+   * io.netty.channel.ChannelPipeline}. Equivalent to {@code name} but for {@link
+   * InboundMessageType}.
+   */
+  String responseName();
 }

prober/src/main/java/google/registry/monitoring/blackbox/metrics/MetricsCollector.java

@@ -0,0 +1,92 @@
+// Copyright 2019 The Nomulus Authors. All Rights Reserved.
+//
+// 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 google.registry.monitoring.blackbox.metrics;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.monitoring.metrics.EventMetric;
+import com.google.monitoring.metrics.ExponentialFitter;
+import com.google.monitoring.metrics.IncrementableMetric;
+import com.google.monitoring.metrics.LabelDescriptor;
+import com.google.monitoring.metrics.MetricRegistryImpl;
+import google.registry.util.NonFinalForTesting;
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+/** Metrics collection instrumentation. */
+@Singleton
+public class MetricsCollector {
+
+  /** Three standard Response types to be recorded as metrics: SUCCESS, FAILURE, or ERROR. */
+  public enum ResponseType {
+    SUCCESS,
+    FAILURE,
+    ERROR
+  }
+
+  // Maximum 1 hour latency, this is not specified by the spec, but given we have a one hour idle
+  // timeout, it seems reasonable that maximum latency is set to 1 hour as well. If we are
+  // approaching anywhere near 1 hour latency, we'd be way out of SLO anyway.
+  private static final ExponentialFitter DEFAULT_LATENCY_FITTER =
+      ExponentialFitter.create(22, 2, 1.0);
+
+  private static final ImmutableSet<LabelDescriptor> LABELS =
+      ImmutableSet.of(
+          LabelDescriptor.create("protocol", "Name of the protocol."),
+          LabelDescriptor.create("request", "Name of outbound request"),
+          LabelDescriptor.create("response", "Name of inbound response"),
+          LabelDescriptor.create("responseType", "Status of action performed"));
+
+  static final IncrementableMetric responsesCounter =
+      MetricRegistryImpl.getDefault()
+          .newIncrementableMetric(
+              "/prober/responses",
+              "Total number of responses received by the prober.",
+              "Responses",
+              LABELS);
+
+  static final EventMetric latencyMs =
+      MetricRegistryImpl.getDefault()
+          .newEventMetric(
+              "/prober/latency_specific_ms",
+              "Round-trip time between a request sent and its corresponding response received.",
+              "Latency Milliseconds",
+              LABELS,
+              DEFAULT_LATENCY_FITTER);
+
+  @Inject
+  MetricsCollector() {}
+
+  /**
+   * Resets all backend metrics.
+   *
+   * <p>This should only used in tests to clear out states. No production code should call this
+   * function.
+   */
+  void resetMetric() {
+    responsesCounter.reset();
+    latencyMs.reset();
+  }
+
+  @NonFinalForTesting
+  public void recordResult(
+      String protocolName,
+      String requestName,
+      String responseName,
+      ResponseType status,
+      long latency) {
+    latencyMs.record(latency, protocolName, requestName, responseName, status.name());
+    responsesCounter.increment(protocolName, requestName, responseName, status.name());
+  }
+}

prober/src/main/java/google/registry/monitoring/blackbox/modules/EppModule.java

@@ -34,8 +34,10 @@ import google.registry.monitoring.blackbox.handlers.SslClientInitializer;
 import google.registry.monitoring.blackbox.messages.EppMessage;
 import google.registry.monitoring.blackbox.messages.EppRequestMessage;
 import google.registry.monitoring.blackbox.messages.EppResponseMessage;
+import google.registry.monitoring.blackbox.metrics.MetricsCollector;
 import google.registry.monitoring.blackbox.modules.CertificateModule.LocalSecrets;
 import google.registry.monitoring.blackbox.tokens.EppToken;
+import google.registry.util.Clock;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.socket.nio.NioSocketChannel;
@@ -86,13 +88,15 @@ public class EppModule {
   @IntoSet
   static ProbingSequence provideEppLoginCreateCheckDeleteCheckProbingSequence(
       EppToken.Persistent token,
+      MetricsCollector metrics,
+      Clock clock,
       @Named("hello") ProbingStep helloStep,
       @Named("loginSuccess") ProbingStep loginSuccessStep,
       @Named("createSuccess") ProbingStep createSuccessStep,
       @Named("checkExists") ProbingStep checkStepFirst,
       @Named("deleteSuccess") ProbingStep deleteSuccessStep,
       @Named("checkNotExists") ProbingStep checkStepSecond) {
-    return new ProbingSequence.Builder(token)
+    return new ProbingSequence.Builder(token, metrics, clock)
         .add(helloStep)
         .add(loginSuccessStep)
         .add(createSuccessStep)
@@ -112,6 +116,8 @@ public class EppModule {
   @IntoSet
   static ProbingSequence provideEppLoginCreateCheckDeleteCheckLogoutProbingSequence(
       EppToken.Transient token,
+      MetricsCollector metrics,
+      Clock clock,
       @Named("hello") ProbingStep helloStep,
       @Named("loginSuccess") ProbingStep loginSuccessStep,
       @Named("createSuccess") ProbingStep createSuccessStep,
@@ -119,7 +125,7 @@ public class EppModule {
       @Named("deleteSuccess") ProbingStep deleteSuccessStep,
       @Named("checkNotExists") ProbingStep checkStepSecond,
       @Named("logout") ProbingStep logoutStep) {
-    return new ProbingSequence.Builder(token)
+    return new ProbingSequence.Builder(token, metrics, clock)
         .add(helloStep)
         .add(loginSuccessStep)
         .add(createSuccessStep)
@@ -253,7 +259,7 @@ public class EppModule {
   static EppRequestMessage provideHelloRequestMessage(
       @Named("greeting") EppResponseMessage greetingResponse) {
 
-    return new EppRequestMessage(greetingResponse, null, (a, b) -> ImmutableMap.of());
+    return new EppRequestMessage("hello", greetingResponse, null, (a, b) -> ImmutableMap.of());
   }
 
   /**
@@ -270,6 +276,7 @@ public class EppModule {
       @Named("eppUserId") String userId,
       @Named("eppPassword") String userPassword) {
     return new EppRequestMessage(
+        "login",
         successResponse,
         loginTemplate,
         (clTrid, domain) ->
@@ -288,6 +295,7 @@ public class EppModule {
       @Named("eppUserId") String userId,
       @Named("eppPassword") String userPassword) {
     return new EppRequestMessage(
+        "login",
         failureResponse,
         loginTemplate,
         (clTrid, domain) ->
@@ -304,6 +312,7 @@ public class EppModule {
       @Named("success") EppResponseMessage successResponse,
       @Named("create") String createTemplate) {
     return new EppRequestMessage(
+        "create",
         successResponse,
         createTemplate,
         (clTrid, domain) ->
@@ -319,6 +328,7 @@ public class EppModule {
       @Named("failure") EppResponseMessage failureResponse,
       @Named("create") String createTemplate) {
     return new EppRequestMessage(
+        "create",
         failureResponse,
         createTemplate,
         (clTrid, domain) ->
@@ -334,6 +344,7 @@ public class EppModule {
       @Named("success") EppResponseMessage successResponse,
       @Named("delete") String deleteTemplate) {
     return new EppRequestMessage(
+        "delete",
         successResponse,
         deleteTemplate,
         (clTrid, domain) ->
@@ -349,6 +360,7 @@ public class EppModule {
       @Named("failure") EppResponseMessage failureResponse,
       @Named("delete") String deleteTemplate) {
     return new EppRequestMessage(
+        "delete",
         failureResponse,
         deleteTemplate,
         (clTrid, domain) ->
@@ -364,6 +376,7 @@ public class EppModule {
       @Named("success") EppResponseMessage successResponse,
       @Named("logout") String logoutTemplate) {
     return new EppRequestMessage(
+        "logout",
         successResponse,
         logoutTemplate,
         (clTrid, domain) -> ImmutableMap.of(CLIENT_TRID_KEY, clTrid));
@@ -376,6 +389,7 @@ public class EppModule {
       @Named("domainExists") EppResponseMessage domainExistsResponse,
       @Named("check") String checkTemplate) {
     return new EppRequestMessage(
+        "check",
         domainExistsResponse,
         checkTemplate,
         (clTrid, domain) ->
@@ -391,6 +405,7 @@ public class EppModule {
       @Named("domainNotExists") EppResponseMessage domainNotExistsResponse,
       @Named("check") String checkTemplate) {
     return new EppRequestMessage(
+        "check",
         domainNotExistsResponse,
         checkTemplate,
         (clTrid, domain) ->

prober/src/main/java/google/registry/monitoring/blackbox/modules/WebWhoisModule.java

@@ -25,8 +25,10 @@ import google.registry.monitoring.blackbox.handlers.SslClientInitializer;
 import google.registry.monitoring.blackbox.handlers.WebWhoisActionHandler;
 import google.registry.monitoring.blackbox.handlers.WebWhoisMessageHandler;
 import google.registry.monitoring.blackbox.messages.HttpRequestMessage;
+import google.registry.monitoring.blackbox.metrics.MetricsCollector;
 import google.registry.monitoring.blackbox.tokens.WebWhoisToken;
 import google.registry.util.CircularList;
+import google.registry.util.Clock;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandler;
@@ -172,9 +174,11 @@ public class WebWhoisModule {
   @Singleton
   @IntoSet
   ProbingSequence provideWebWhoisSequence(
-      @WebWhoisProtocol ProbingStep probingStep, WebWhoisToken webWhoisToken) {
-
-    return new ProbingSequence.Builder(webWhoisToken).add(probingStep).build();
+      @WebWhoisProtocol ProbingStep probingStep,
+      WebWhoisToken webWhoisToken,
+      MetricsCollector metrics,
+      Clock clock) {
+    return new ProbingSequence.Builder(webWhoisToken, metrics, clock).add(probingStep).build();
   }
 
   @Provides

prober/src/test/java/google/registry/monitoring/blackbox/ProbingSequenceTest.java

@@ -16,9 +16,9 @@ package google.registry.monitoring.blackbox;
 
 import static com.google.common.truth.Truth.assertThat;
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doCallRealMethod;
 import static org.mockito.Mockito.doReturn;
-import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
@@ -27,10 +27,16 @@ import google.registry.monitoring.blackbox.connection.Protocol;
 import google.registry.monitoring.blackbox.exceptions.FailureException;
 import google.registry.monitoring.blackbox.exceptions.UndeterminedStateException;
 import google.registry.monitoring.blackbox.exceptions.UnrecoverableStateException;
+import google.registry.monitoring.blackbox.messages.OutboundMessageType;
+import google.registry.monitoring.blackbox.metrics.MetricsCollector;
+import google.registry.monitoring.blackbox.metrics.MetricsCollector.ResponseType;
 import google.registry.monitoring.blackbox.tokens.Token;
+import google.registry.testing.FakeClock;
+import google.registry.util.Clock;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.embedded.EmbeddedChannel;
+import org.joda.time.Duration;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -53,6 +59,11 @@ import org.mockito.Mockito;
 @RunWith(JUnit4.class)
 public class ProbingSequenceTest {
 
+  private static final String PROTOCOL_NAME = "PROTOCOL";
+  private static final String MESSAGE_NAME = "MESSAGE";
+  private static final String RESPONSE_NAME = "RESPONSE";
+  private static final Duration LATENCY = Duration.millis(2L);
+
   /** Default mock {@link ProbingAction} returned when generating an action with a mockStep. */
   private ProbingAction mockAction = Mockito.mock(ProbingAction.class);
 
@@ -71,22 +82,39 @@ public class ProbingSequenceTest {
    */
   private Protocol mockProtocol = Mockito.mock(Protocol.class);
 
+  /**
+   * Default mock {@link OutboundMessageType} returned by {@code mockStep} and occasionally other
+   * mock {@link ProbingStep}s.
+   */
+  private OutboundMessageType mockMessage = Mockito.mock(OutboundMessageType.class);
+
   /**
    * {@link EmbeddedChannel} used to create new {@link ChannelPromise} objects returned by mock
    * {@link ProbingAction}s on their {@code call} methods.
    */
   private EmbeddedChannel channel = new EmbeddedChannel();
 
+  /** Default mock {@link MetricsCollector} passed into each {@link ProbingSequence} tested */
+  private MetricsCollector metrics = Mockito.mock(MetricsCollector.class);
+
+  /** Default mock {@link Clock} passed into each {@link ProbingSequence} tested */
+  private Clock clock = new FakeClock();
+
   @Before
   public void setup() {
     // To avoid a NullPointerException, we must have a protocol return persistent connection as
     // false.
     doReturn(true).when(mockProtocol).persistentConnection();
+    doReturn(PROTOCOL_NAME).when(mockProtocol).name();
 
     // In order to avoid a NullPointerException, we must have the protocol returned that stores
     // persistent connection as false.
     doReturn(mockProtocol).when(mockStep).protocol();
 
+    doReturn(MESSAGE_NAME).when(mockMessage).name();
+    doReturn(RESPONSE_NAME).when(mockMessage).responseName();
+    doReturn(mockMessage).when(mockStep).messageTemplate();
+
     // Allows for test if channel is accurately set.
     doCallRealMethod().when(mockToken).setChannel(any(Channel.class));
     doCallRealMethod().when(mockToken).channel();
@@ -102,7 +130,7 @@ public class ProbingSequenceTest {
     ProbingStep thirdStep = Mockito.mock(ProbingStep.class);
 
     ProbingSequence sequence =
-        new ProbingSequence.Builder(mockToken)
+        new ProbingSequence.Builder(mockToken, metrics, clock)
             .add(firstStep)
             .add(secondStep)
             .add(thirdStep)
@@ -127,7 +155,7 @@ public class ProbingSequenceTest {
     ProbingStep thirdStep = Mockito.mock(ProbingStep.class);
 
     ProbingSequence sequence =
-        new ProbingSequence.Builder(mockToken)
+        new ProbingSequence.Builder(mockToken, metrics, clock)
             .add(thirdStep)
             .add(secondStep)
             .markFirstRepeated()
@@ -148,8 +176,15 @@ public class ProbingSequenceTest {
 
   @Test
   public void testRunStep_Success() throws UndeterminedStateException {
-    // Always returns a succeeded future on call to mockAction.
-    doReturn(channel.newSucceededFuture()).when(mockAction).call();
+    // Always returns a succeeded future on call to mockAction. Also advances the FakeClock by
+    // standard LATENCY to check right latency is recorded.
+    doAnswer(
+            answer -> {
+              ((FakeClock) clock).advanceBy(LATENCY);
+              return channel.newSucceededFuture();
+            })
+        .when(mockAction)
+        .call();
 
     // Has mockStep always return mockAction on call to generateAction.
     doReturn(mockAction).when(mockStep).generateAction(any(Token.class));
@@ -165,7 +200,10 @@ public class ProbingSequenceTest {
 
     // Build testable sequence from mocked components.
     ProbingSequence sequence =
-        new ProbingSequence.Builder(mockToken).add(mockStep).add(secondStep).build();
+        new ProbingSequence.Builder(mockToken, metrics, clock)
+            .add(mockStep)
+            .add(secondStep)
+            .build();
 
     sequence.start();
 
@@ -182,12 +220,25 @@ public class ProbingSequenceTest {
 
     // We should have modified the token's channel after the first, succeeded step.
     assertThat(mockToken.channel()).isEqualTo(channel);
+
+    // Verifies that metrics records the right kind of result (a success with the input protocol
+    // name and message name).
+    verify(metrics)
+        .recordResult(
+            PROTOCOL_NAME, MESSAGE_NAME, RESPONSE_NAME, ResponseType.SUCCESS, LATENCY.getMillis());
   }
 
   @Test
   public void testRunLoop_Success() throws UndeterminedStateException {
-    // Always returns a succeeded future on call to mockAction.
-    doReturn(channel.newSucceededFuture()).when(mockAction).call();
+    // Always returns a succeeded future on call to mockAction. Also advances the FakeClock by
+    // standard LATENCY to check right latency is recorded.
+    doAnswer(
+            answer -> {
+              ((FakeClock) clock).advanceBy(LATENCY);
+              return channel.newSucceededFuture();
+            })
+        .when(mockAction)
+        .call();
 
     // Has mockStep always return mockAction on call to generateAction
     doReturn(mockAction).when(mockStep).generateAction(mockToken);
@@ -199,9 +250,21 @@ public class ProbingSequenceTest {
     // Necessary for success of ProbingSequence runStep method as it calls get().protocol().
     doReturn(mockProtocol).when(secondStep).protocol();
 
+    // Necessary for success of ProbingSequence recording metrics as it calls get()
+    // .messageTemplate.name().
+    doReturn(mockMessage).when(secondStep).messageTemplate();
+
     // We ensure that secondStep has necessary attributes to be successful step to pass on to
-    // mockStep once more.
-    doReturn(channel.newSucceededFuture()).when(secondAction).call();
+    // mockStep once more. Also have clock time pass by standard LATENCY to ensure right latency
+    // is recorded.
+    doAnswer(
+            answer -> {
+              ((FakeClock) clock).advanceBy(LATENCY);
+              return channel.newSucceededFuture();
+            })
+        .when(secondAction)
+        .call();
+
     doReturn(secondAction).when(secondStep).generateAction(mockToken);
 
     // We get a secondToken that is returned when we are on our second loop in the sequence. This
@@ -217,12 +280,15 @@ public class ProbingSequenceTest {
 
     // Build testable sequence from mocked components.
     ProbingSequence sequence =
-        new ProbingSequence.Builder(mockToken).add(mockStep).add(secondStep).build();
+        new ProbingSequence.Builder(mockToken, metrics, clock)
+            .add(mockStep)
+            .add(secondStep)
+            .build();
 
     sequence.start();
 
     // We expect to have generated actions from mockStep twice (once for mockToken and once for
-    // secondToken), and we expectto have called each generated action only once, as when we move
+    // secondToken), and we expect to have called each generated action only once, as when we move
     // on to mockStep the second time, it will terminate the sequence after calling thirdAction.
     verify(mockStep).generateAction(mockToken);
     verify(mockStep).generateAction(secondToken);
@@ -236,6 +302,18 @@ public class ProbingSequenceTest {
 
     // We should have modified the token's channel after the first, succeeded step.
     assertThat(mockToken.channel()).isEqualTo(channel);
+
+    // Verifies that metrics records the right kind of result (a success with the input protocol
+    // name and message name) two times: once for mockStep and once for secondStep.
+    verify(metrics, times(2))
+        .recordResult(
+            PROTOCOL_NAME, MESSAGE_NAME, RESPONSE_NAME, ResponseType.SUCCESS, LATENCY.getMillis());
+
+    // Verify that on second pass, since we purposely throw UnrecoverableStateException, we
+    // record the ERROR. Also, we haven't had any time pass in the fake clock, so recorded
+    // latency should be 0.
+    verify(metrics)
+        .recordResult(PROTOCOL_NAME, MESSAGE_NAME, RESPONSE_NAME, ResponseType.ERROR, 0L);
   }
 
   /**
@@ -250,14 +328,26 @@ public class ProbingSequenceTest {
     ProbingStep secondStep = Mockito.mock(ProbingStep.class);
 
     // We create a second token that when used to generate an action throws an
-    // UnrecoverableStateException to terminate the sequence
+    // UnrecoverableStateException to terminate the sequence.
     Token secondToken = Mockito.mock(Token.class);
     doReturn(secondToken).when(mockToken).next();
-    doThrow(new UnrecoverableStateException("")).when(mockStep).generateAction(secondToken);
+
+    // When we throw the UnrecoverableStateException, we ensure that the right latency is
+    // recorded by advancing the clock by LATENCY.
+    doAnswer(
+            answer -> {
+              ((FakeClock) clock).advanceBy(LATENCY);
+              throw new UnrecoverableStateException("");
+            })
+        .when(mockStep)
+        .generateAction(secondToken);
 
     // Build testable sequence from mocked components.
     ProbingSequence sequence =
-        new ProbingSequence.Builder(mockToken).add(mockStep).add(secondStep).build();
+        new ProbingSequence.Builder(mockToken, metrics, clock)
+            .add(mockStep)
+            .add(secondStep)
+            .build();
 
     sequence.start();
 
@@ -278,8 +368,15 @@ public class ProbingSequenceTest {
 
   @Test
   public void testRunStep_FailureRunning() throws UndeterminedStateException {
-    // Returns a failed future when calling the generated mock action.
-    doReturn(channel.newFailedFuture(new FailureException(""))).when(mockAction).call();
+    // Returns a failed future when calling the generated mock action. Also advances FakeClock by
+    // LATENCY in order to check right latency is recorded.
+    doAnswer(
+            answer -> {
+              ((FakeClock) clock).advanceBy(LATENCY);
+              return channel.newFailedFuture(new FailureException(""));
+            })
+        .when(mockAction)
+        .call();
 
     // Returns mock action on call to generate action for ProbingStep.
     doReturn(mockAction).when(mockStep).generateAction(mockToken);
@@ -290,16 +387,42 @@ public class ProbingSequenceTest {
     // We only expect to have called this action once, as we only get it from one generateAction
     // call.
     verify(mockAction).call();
+
+    // Verifies that metrics records the right kind of result (a failure with the input protocol
+    // name and message name).
+    verify(metrics)
+        .recordResult(
+            PROTOCOL_NAME, MESSAGE_NAME, RESPONSE_NAME, ResponseType.FAILURE, LATENCY.getMillis());
+
+    // Verify that on second pass, since we purposely throw UnrecoverableStateException, we
+    // record the ERROR. We also should make sure LATENCY seconds have passed.
+    verify(metrics)
+        .recordResult(
+            PROTOCOL_NAME, MESSAGE_NAME, RESPONSE_NAME, ResponseType.ERROR, LATENCY.getMillis());
   }
 
   @Test
   public void testRunStep_FailureGenerating() throws UndeterminedStateException {
-    // Create a mock first step that returns the dummy action when called to generate an action.
-    doThrow(UndeterminedStateException.class).when(mockStep).generateAction(mockToken);
+    // Mock first step throws an error when generating the first action, and advances the clock
+    // by LATENCY.
+    doAnswer(
+            answer -> {
+              ((FakeClock) clock).advanceBy(LATENCY);
+              throw new UndeterminedStateException("");
+            })
+        .when(mockStep)
+        .generateAction(mockToken);
 
+    // Tests generic behavior we expect when we fail in generating or calling an action.
     testActionFailure();
 
     // We expect to have never called this action, as we fail each time whenever generating actions.
     verify(mockAction, times(0)).call();
+
+    // Verify that we record two errors, first for being unable to generate the action, second
+    // for terminating the sequence.
+    verify(metrics, times(2))
+        .recordResult(
+            PROTOCOL_NAME, MESSAGE_NAME, RESPONSE_NAME, ResponseType.ERROR, LATENCY.getMillis());
   }
 }

prober/src/test/java/google/registry/monitoring/blackbox/messages/TestMessage.java

@@ -38,4 +38,14 @@ public class TestMessage implements OutboundMessageType, InboundMessageType {
     message = args[0];
     return this;
   }
+
+  @Override
+  public String name() {
+    return message;
+  }
+
+  @Override
+  public String responseName() {
+    return message;
+  }
 }

prober/src/test/java/google/registry/monitoring/blackbox/metrics/MetricsCollectorTest.java

@@ -0,0 +1,100 @@
+// Copyright 2019 The Nomulus Authors. All Rights Reserved.
+//
+// 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 google.registry.monitoring.blackbox.metrics;
+
+import static com.google.monitoring.metrics.contrib.DistributionMetricSubject.assertThat;
+import static com.google.monitoring.metrics.contrib.LongMetricSubject.assertThat;
+
+import com.google.common.collect.ImmutableSet;
+import google.registry.monitoring.blackbox.metrics.MetricsCollector.ResponseType;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link MetricsCollector}. */
+@RunWith(JUnit4.class)
+public class MetricsCollectorTest {
+
+  private final String requestName = "request";
+  private final String responseName = "response";
+  private final String protocol = "protocol";
+
+  private final MetricsCollector metrics = new MetricsCollector();
+
+  @Before
+  public void setUp() {
+    metrics.resetMetric();
+  }
+
+  @Test
+  public void testOneRecord() {
+    metrics.recordResult(protocol, requestName, responseName, ResponseType.SUCCESS, 100);
+
+    assertThat(MetricsCollector.responsesCounter)
+        .hasValueForLabels(1, protocol, requestName, responseName, ResponseType.SUCCESS.name())
+        .and()
+        .hasNoOtherValues();
+
+    assertThat(MetricsCollector.latencyMs)
+        .hasDataSetForLabels(
+            ImmutableSet.of(100), protocol, requestName, responseName, ResponseType.SUCCESS.name())
+        .and()
+        .hasNoOtherValues();
+  }
+
+  @Test
+  public void testMultipleRecords_sameStatus() {
+    metrics.recordResult(protocol, requestName, responseName, ResponseType.FAILURE, 100);
+    metrics.recordResult(protocol, requestName, responseName, ResponseType.FAILURE, 200);
+
+    assertThat(MetricsCollector.responsesCounter)
+        .hasValueForLabels(2, protocol, requestName, responseName, ResponseType.FAILURE.name())
+        .and()
+        .hasNoOtherValues();
+
+    assertThat(MetricsCollector.latencyMs)
+        .hasDataSetForLabels(
+            ImmutableSet.of(100, 200),
+            protocol,
+            requestName,
+            responseName,
+            ResponseType.FAILURE.name())
+        .and()
+        .hasNoOtherValues();
+  }
+
+  @Test
+  public void testMultipleRecords_differentStatus() {
+    metrics.recordResult(protocol, requestName, responseName, ResponseType.SUCCESS, 100);
+    metrics.recordResult(protocol, requestName, responseName, ResponseType.FAILURE, 200);
+
+    assertThat(MetricsCollector.responsesCounter)
+        .hasValueForLabels(1, protocol, requestName, responseName, ResponseType.SUCCESS.name())
+        .and()
+        .hasValueForLabels(1, protocol, requestName, responseName, ResponseType.FAILURE.name())
+        .and()
+        .hasNoOtherValues();
+
+    assertThat(MetricsCollector.latencyMs)
+        .hasDataSetForLabels(
+            ImmutableSet.of(100), protocol, requestName, responseName, ResponseType.SUCCESS.name())
+        .and()
+        .hasDataSetForLabels(
+            ImmutableSet.of(200), protocol, requestName, responseName, ResponseType.FAILURE.name())
+        .and()
+        .hasNoOtherValues();
+  }
+}

prober/src/test/java/google/registry/monitoring/blackbox/util/EppUtils.java

@@ -92,13 +92,14 @@ public class EppUtils {
 
   /** Returns standard hello request with supplied response. */
   public static EppRequestMessage getHelloMessage(EppResponseMessage greetingResponse) {
-    return new EppRequestMessage(greetingResponse, null, (a, b) -> ImmutableMap.of());
+    return new EppRequestMessage("hello", greetingResponse, null, (a, b) -> ImmutableMap.of());
   }
 
   /** Returns standard login request with supplied userId, userPassword, and response. */
   public static EppRequestMessage getLoginMessage(
       EppResponseMessage response, String userId, String userPassword) {
     return new EppRequestMessage(
+        "login",
         response,
         "login.xml",
         (clTrid, domain) ->
@@ -111,6 +112,7 @@ public class EppUtils {
   /** Returns standard create request with supplied response. */
   public static EppRequestMessage getCreateMessage(EppResponseMessage response) {
     return new EppRequestMessage(
+        "create",
         response,
         "create.xml",
         (clTrid, domain) ->
@@ -122,6 +124,7 @@ public class EppUtils {
   /** Returns standard delete request with supplied response. */
   public static EppRequestMessage getDeleteMessage(EppResponseMessage response) {
     return new EppRequestMessage(
+        "delete",
         response,
         "delete.xml",
         (clTrid, domain) ->
@@ -133,6 +136,7 @@ public class EppUtils {
   /** Returns standard logout request with supplied response. */
   public static EppRequestMessage getLogoutMessage(EppResponseMessage successResponse) {
     return new EppRequestMessage(
+        "logout",
         successResponse,
         "logout.xml",
         (clTrid, domain) -> ImmutableMap.of(CLIENT_TRID_KEY, clTrid));
@@ -141,6 +145,7 @@ public class EppUtils {
   /** Returns standard check request with supplied response. */
   public static EppRequestMessage getCheckMessage(EppResponseMessage response) {
     return new EppRequestMessage(
+        "check",
         response,
         "check.xml",
         (clTrid, domain) ->