Add Outcome references to reconstruct provenance

src/main/java/com/microsoft/dhalion/api/MetricsProvider.java

@@ -11,6 +11,7 @@ import com.microsoft.dhalion.core.Measurement;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.Collection;
+import java.util.Collections;
 
 /**
  * A {@link MetricsProvider} implements common utility methods to produce {@link Measurement}s. In some cases it will
@@ -43,6 +44,24 @@ public interface MetricsProvider {
     throw new UnsupportedOperationException("This method is not implemented in the metrics provider");
   }
 
+  /**
+   * @param startTime metric aggregation window start time, endTime = startTime - duration
+   * @param duration  the duration for which the metric was aggregated
+   * @param metric    ids of the metrics
+   * @param component ids of the components for which the metric is needed
+   * @return collection of {@link Measurement}s
+   * @see #getMeasurements(Instant, Duration, Collection, Collection)
+   */
+  default Collection<Measurement> getMeasurements(Instant startTime,
+                                                  Duration duration,
+                                                  String metric,
+                                                  String component) {
+    return getMeasurements(startTime,
+                           duration,
+                           Collections.singletonList(metric),
+                           Collections.singletonList(component));
+  }
+
   /**
    * Release all acquired resources and prepare for termination of this instance
    */

src/main/java/com/microsoft/dhalion/core/Action.java

@@ -9,18 +9,35 @@ package com.microsoft.dhalion.core;
 import com.microsoft.dhalion.api.IResolver;
 
 import java.time.Instant;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 
 /**
  * {@link Action} is a representation of a action taken by {@link IResolver} to improve system health.
  */
 public class Action extends Outcome {
-  public Action(String type, Instant instant, Collection<String> assignments) {
+  private final Collection<Diagnosis> diagnosis = new ArrayList<>();
+
+  public Action(String type, Instant instant, Collection<String> assignments, Collection<Diagnosis> diagnosis) {
     super(type, instant, assignments);
+    if (diagnosis != null) {
+      this.diagnosis.addAll(diagnosis);
+    }
   }
 
-  public Action(int id, String symptomType, Instant instant, Collection<String> assignments) {
-    super(id, symptomType, instant, assignments);
+  public Action(int id, String type, Instant instant, Collection<String> assignments, Collection<Diagnosis> diagnosis) {
+    super(id, type, instant, assignments);
+    if (diagnosis != null) {
+      this.diagnosis.addAll(diagnosis);
+    }
+  }
+
+  /**
+   * @return {@link Diagnosis} referred to when this {@link Action} was created
+   */
+  public Collection<Diagnosis> diagnosis() {
+    return Collections.unmodifiableCollection(diagnosis);
   }
 
   @Override

src/main/java/com/microsoft/dhalion/core/ActionTable.java

@@ -133,7 +133,8 @@ public class ActionTable extends OutcomeTable<Action> {
     return new Action(id.get(index),
                       type.get(index),
                       Instant.ofEpochMilli(timeStamp.get(index)),
-                      Collections.singletonList(assignment.get(index)));
+                      Collections.singletonList(assignment.get(index)),
+                      null);
   }
 
 

src/main/java/com/microsoft/dhalion/core/Diagnosis.java

@@ -7,19 +7,44 @@
 package com.microsoft.dhalion.core;
 
 import java.time.Instant;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 
 /**
  * A {@link Diagnosis} is a representation of a possible causes of one or more {@link Symptom}s. For e.g. resource
  * under-provisioning
  */
 public class Diagnosis extends Outcome {
-  public Diagnosis(String type, Instant instant, Collection<String> assignments) {
+  // symtoms referred to create this instance
+  private final Collection<Symptom> symptoms = new ArrayList<>();
+
+  public Diagnosis(String type,
+                   Instant instant,
+                   Collection<String> assignments,
+                   Collection<Symptom> symptoms) {
     super(type, instant, assignments);
+    if (symptoms != null) {
+      this.symptoms.addAll(symptoms);
+    }
   }
 
-  public Diagnosis(int id, String symptomType, Instant instant, Collection<String> assignments) {
-    super(id, symptomType, instant, assignments);
+  public Diagnosis(int id,
+                   String type,
+                   Instant instant,
+                   Collection<String> assignments,
+                   Collection<Symptom> symptoms) {
+    super(id, type, instant, assignments);
+    if (symptoms != null) {
+      this.symptoms.addAll(symptoms);
+    }
+  }
+
+  /**
+   * @return {@link Symptom}s referred to when this {@link Diagnosis} was created
+   */
+  public Collection<Symptom> symptoms() {
+    return Collections.unmodifiableCollection(symptoms);
   }
 
   @Override

src/main/java/com/microsoft/dhalion/core/DiagnosisTable.java

@@ -133,7 +133,8 @@ public class DiagnosisTable extends OutcomeTable<Diagnosis> {
     return new Diagnosis(id.get(index),
                          type.get(index),
                          Instant.ofEpochMilli(timeStamp.get(index)),
-                         Collections.singletonList(assignment.get(index)));
+                         Collections.singletonList(assignment.get(index)),
+                         null);
   }
 
 

src/main/java/com/microsoft/dhalion/core/MeasurementsTable.java

@@ -172,6 +172,16 @@ public class MeasurementsTable {
     return new MeasurementsTable(result);
   }
 
+  /**
+   * Retains all {@link Measurement}s created at the given timestamp.
+   *
+   * @param timestamp {@link Measurement} creation time.
+   * @return {@link MeasurementsTable} containing filtered {@link Measurement}s
+   */
+  public MeasurementsTable instant(Instant timestamp) {
+    return between(timestamp, timestamp);
+  }
+
   /**
    * Retains only the {@link Measurement}s whose value is between <code>low</code> and <code>high</code>, both
    * inclusive.

src/main/java/com/microsoft/dhalion/core/Outcome.java

@@ -9,8 +9,8 @@ package com.microsoft.dhalion.core;
 import com.microsoft.dhalion.api.IDetector;
 
 import java.time.Instant;
+import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.concurrent.atomic.AtomicInteger;
 
 /**
@@ -30,7 +30,7 @@ abstract class Outcome {
   private final Instant instant;
 
   // ids of objects to which this outcome can be attributed to, for e.g. slow instance's id
-  private final Collection<String> assignments;
+  private final Collection<String> assignments = new ArrayList<>();
 
   Outcome(String type, Instant instant, Collection<String> assignments) {
     this(idGenerator.incrementAndGet(), type, instant, assignments);
@@ -40,7 +40,9 @@ abstract class Outcome {
     this.id = id;
     this.type = type;
     this.instant = instant;
-    this.assignments = Collections.unmodifiableCollection(assignments);
+    if (assignments != null) {
+      this.assignments.addAll(assignments);
+    }
   }
 
   public int id() {

src/main/java/com/microsoft/dhalion/core/Symptom.java

@@ -7,6 +7,7 @@
 package com.microsoft.dhalion.core;
 
 import java.time.Instant;
+import java.util.ArrayList;
 import java.util.Collection;
 
 /**
@@ -14,12 +15,35 @@ import java.util.Collection;
  * distributed application. For e.g. identification of irregular processing latency.
  */
 public class Symptom extends Outcome {
-  public Symptom(String symptomType, Instant instant, Collection<String> assignments) {
+  // measurements referred to create this instance
+  private final Collection<Measurement> measurements = new ArrayList<>();
+
+  public Symptom(String symptomType,
+                 Instant instant,
+                 Collection<String> assignments,
+                 Collection<Measurement> measurements) {
     super(symptomType, instant, assignments);
+    if (measurements != null) {
+      this.measurements.addAll(measurements);
+    }
   }
 
-  public Symptom(int id, String symptomType, Instant instant, Collection<String> assignments) {
+  public Symptom(int id,
+                 String symptomType,
+                 Instant instant,
+                 Collection<String> assignments,
+                 Collection<Measurement> measurements) {
     super(id, symptomType, instant, assignments);
+    if (measurements != null) {
+      this.measurements.addAll(measurements);
+    }
+  }
+
+  /**
+   * @return {@link Measurement}s referred to when this {@link Symptom} was created
+   */
+  public Collection<Measurement> measurements() {
+    return measurements;
   }
 
   @Override

src/main/java/com/microsoft/dhalion/core/SymptomsTable.java

@@ -133,7 +133,8 @@ public class SymptomsTable extends OutcomeTable<Symptom> {
     return new Symptom(id.get(index),
                        type.get(index),
                        Instant.ofEpochMilli(timeStamp.get(index)),
-                       Collections.singletonList(assignment.get(index)));
+                       Collections.singletonList(assignment.get(index)),
+                       null);
   }
 
 

src/main/java/com/microsoft/dhalion/policy/PoliciesExecutor.java

@@ -75,7 +75,7 @@ public class PoliciesExecutor {
         policyContextMap.get(policy).symptomsTableBuilder.addAll(symptoms);
 
         Collection<Diagnosis> diagnosis = policy.executeDiagnosers(symptoms);
-        policyContextMap.get(policy).diagnsisTableBuilder.addAll(diagnosis);
+        policyContextMap.get(policy).diagnosisTableBuilder.addAll(diagnosis);
 
         Collection<Action> actions = policy.executeResolvers(diagnosis);
         policyContextMap.get(policy).actionTableBuilder.addAll(actions);
@@ -99,13 +99,13 @@ public class PoliciesExecutor {
   public static class ExecutionContext {
     private final MeasurementsTable.Builder measurementsTableBuilder;
     private final SymptomsTable.Builder symptomsTableBuilder;
-    private final DiagnosisTable.Builder diagnsisTableBuilder;
+    private final DiagnosisTable.Builder diagnosisTableBuilder;
     private final ActionTable.Builder actionTableBuilder;
 
     private ExecutionContext() {
       measurementsTableBuilder = new MeasurementsTable.Builder();
       symptomsTableBuilder = new SymptomsTable.Builder();
-      diagnsisTableBuilder = new DiagnosisTable.Builder();
+      diagnosisTableBuilder = new DiagnosisTable.Builder();
       actionTableBuilder = new ActionTable.Builder();
     }
 
@@ -118,7 +118,7 @@ public class PoliciesExecutor {
     }
 
     public DiagnosisTable diagnosis() {
-      return diagnsisTableBuilder.get();
+      return diagnosisTableBuilder.get();
     }
 
     public ActionTable actions() {

src/test/java/com/microsoft/dhalion/core/SymptomsTableTest.java

@@ -37,7 +37,7 @@ public class SymptomsTableTest {
     int value = 10;
     for (int id : ids) {
       for (String type : types) {
-        symptoms.add(new Symptom(id, type, Instant.ofEpochMilli(value), attributions));
+        symptoms.add(new Symptom(id, type, Instant.ofEpochMilli(value), attributions, null));
         value += 10;
       }
     }