Add Copyright and minor refactoring

src/main/java/com/microsoft/dhalion/Utils.java

@@ -1,20 +1,15 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion;
 
-import java.util.ArrayList;
-
-import static java.awt.SystemColor.text;
-
 public class Utils {
 
   public static String getCompositeName(String... names) {
-    if (names.length > 0) {
-      String text = names[0];
-      for (int i = 1; i < names.length; i++) {
-        text = text + "_" + names[i];
+    return names.length > 0 ? String.join("_", names) : "";
   }
-      return text;
-    }
-    return "";
-  }
-
 }

src/main/java/com/microsoft/dhalion/detectors/AboveThresholdDetector.java

@@ -1,33 +1,39 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.detectors;
 
-import com.microsoft.dhalion.Utils;
 import com.microsoft.dhalion.conf.PolicyConfig;
 import com.microsoft.dhalion.core.Measurement;
 import com.microsoft.dhalion.core.MeasurementsTable;
 import com.microsoft.dhalion.core.MeasurementsTable.SortKey;
 import com.microsoft.dhalion.core.Symptom;
 
-import javax.inject.Inject;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.logging.Logger;
 
 /**
  * The AboveThreshold Detector evaluates whether the values of a certain metric are above a user-defined
  * threshold during a time window and in this case returns a symptom. The detector takes as input the metric name,
  * the threshold and the time window specified as the number of latest checkpoints. It generates a
- * SYMPTOM_HIGH_metricName symptom that is parameterized by the metric name.
- *
+ * {@link AboveThresholdDetector}_metricName symptom that is parameterized by the metric name.
+ * <p>
  * For example, if the threshold is set to 90, the number of latest checkpoints is set to 2 and the metric is set to
- * CPU_UTILIZATION, then the detector will return a symptom SYMPTOM_HIGH_CPU_UTILIZATION only when the CPU_UTILIZATION
- * is above 90 consistently during the last 2 invocations of the policy. By default the number of checkpoints is set
- * to 1 which means that the detector considers only the current value when determining whether to return a symptom.
+ * CPU_UTILIZATION, then the detector will return a symptom AboveThresholdDetector_CPU_UTILIZATION only when the
+ * CPU_UTILIZATION is above 90 consistently during the last 2 invocations of the policy. By default the number of
+ * checkpoints is set to 1 which means that the detector considers only the current value when determining whether to
+ * return a symptom.
  */
 public class AboveThresholdDetector extends Detector {
-  public static String SYMPTOM_HIGH = AboveThresholdDetector.class.getSimpleName();
-
-  public static final String HIGH_THRESHOLD_CONF = "AboveThresholdDetector.threshold";
-  public static final String ABOVE_THRESHOLD_NO_CHECKPOINTS = "AboveThresholdDetector.noCheckpoints";
+  public static final String SYMPTOM_HIGH = AboveThresholdDetector.class.getSimpleName();
+  static final String HIGH_THRESHOLD_CONF = "AboveThresholdDetector.threshold";
+  static final String ABOVE_THRESHOLD_NO_CHECKPOINTS = "AboveThresholdDetector.noCheckpoints";
 
   private final double highThreshold;
   private String metricName;
@@ -35,38 +41,38 @@ public class AboveThresholdDetector extends Detector {
 
   private static final Logger LOG = Logger.getLogger(AboveThresholdDetector.class.getSimpleName());
 
-
-  @Inject
   public AboveThresholdDetector(PolicyConfig policyConfig, String metricName) {
-    this.highThreshold = (Double) policyConfig.getConfig(Utils.getCompositeName(HIGH_THRESHOLD_CONF, metricName));
-    this.noCheckpoints = (Double) policyConfig.getConfig(Utils.getCompositeName(ABOVE_THRESHOLD_NO_CHECKPOINTS,
-                                                                                metricName), 1);
+    this.highThreshold = (Double) policyConfig.getConfig(String.join("_", HIGH_THRESHOLD_CONF, metricName));
+    this.noCheckpoints
+        = (Double) policyConfig.getConfig(String.join("_", ABOVE_THRESHOLD_NO_CHECKPOINTS, metricName), 1);
     this.metricName = metricName;
   }
 
   @Override
   public Collection<Symptom> detect(Collection<Measurement> measurements) {
-    ArrayList<Symptom> result = new ArrayList<>();
-    if (measurements.size() > 0) {
+    if (measurements.isEmpty()) {
+      return Collections.emptyList();
+    }
+
+    Collection<String> assignments = new ArrayList<>();
     MeasurementsTable measurementsTable = context.measurements().type(metricName).sort(false, SortKey.TIME_STAMP);
-      Collection<String> aboveThresholdAssignments = new ArrayList();
     for (String component : measurementsTable.uniqueComponents()) {
       MeasurementsTable componentData = measurementsTable.component(component);
       for (String instance : componentData.uniqueInstances()) {
-          MeasurementsTable instanceData = measurementsTable.instance(instance).last((int) noCheckpoints);
+        MeasurementsTable instanceData = componentData.instance(instance).last((int) noCheckpoints);
         if (instanceData.valueBetween(highThreshold, Double.MAX_VALUE).size() == noCheckpoints) {
-            LOG.fine(String.format("Instance %s has values above the limit for the last %s checkpoints", instance,
-                                   noCheckpoints));
-            aboveThresholdAssignments.add(instance);
+          LOG.fine(String.format("Instance %s has values above the limit (%s) for the last %s checkpoints",
+                                 instance, highThreshold, noCheckpoints));
+          assignments.add(instance);
         }
       }
     }
-      if (aboveThresholdAssignments.size() > 0) {
-        Symptom s = new Symptom(Utils.getCompositeName(SYMPTOM_HIGH, metricName), context.checkpoint(),
-                                aboveThresholdAssignments);
-        result.add(s);
+
+    if (assignments.isEmpty()) {
+      return Collections.emptyList();
     }
-    }
-    return result;
+
+    Symptom s = new Symptom(String.join("_", SYMPTOM_HIGH, metricName), context.checkpoint(), assignments);
+    return Collections.singletonList(s);
   }
 }

src/main/java/com/microsoft/dhalion/detectors/BelowThresholdDetector.java

@@ -1,33 +1,40 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.detectors;
 
-import com.microsoft.dhalion.Utils;
 import com.microsoft.dhalion.conf.PolicyConfig;
 import com.microsoft.dhalion.core.Measurement;
 import com.microsoft.dhalion.core.MeasurementsTable;
 import com.microsoft.dhalion.core.MeasurementsTable.SortKey;
 import com.microsoft.dhalion.core.Symptom;
 
-import javax.inject.Inject;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.logging.Logger;
 
 /**
  * The BelowThreshold Detector evaluates whether the values of a certain metric are below a user-defined
  * threshold during a time window and in this case returns a symptom. The detector takes as input the metric name,
  * the threshold and the time window specified as the number of latest checkpoints. It generates a
- * SYMPTOM_LOW_metricName symptom that is parameterized by the metric name.
+ * {@link BelowThresholdDetector}_metricName symptom that is parameterized by the metric name.
  * <p>
  * For example, if the threshold is set to 10, the number of latest checkpoints is set to 2 and the metric is set to
- * CPU_UTILIZATION, then the detector will return a symptom SYMPTOM_LOW_CPU_UTILIZATION only when the CPU_UTILIZATION
- * is below 10 consistently during the last 2 invocations of the policy. By default the number of checkpoints is set
- * to 1 which means that the detector considers only the current value when determining whether to return a symptom.
+ * CPU_UTILIZATION, then the detector will return a symptom {@link BelowThresholdDetector}_CPU_UTILIZATION only when
+ * the CPU_UTILIZATION is below 10 consistently during the last 2 invocations of the policy. By default the number of
+ * checkpoints is set to 1 which means that the detector considers only the current value when determining whether to
+ * return a symptom.
  */
 public class BelowThresholdDetector extends Detector {
-  public static String SYMPTOM_LOW = BelowThresholdDetector.class.getSimpleName();
+  public static final String SYMPTOM_LOW = BelowThresholdDetector.class.getSimpleName();
 
-  public static final String LOW_THRESHOLD_CONF = "BelowThresholdDetector.threshold";
-  public static final String BELOW_THRESHOLD_NO_CHECKPOINTS = "BelowThresholdDetector.noCheckpoints";
+  static final String LOW_THRESHOLD_CONF = "BelowThresholdDetector.threshold";
+  static final String BELOW_THRESHOLD_NO_CHECKPOINTS = "BelowThresholdDetector.noCheckpoints";
 
   private final double lowThreshold;
   private String metricName;
@@ -35,37 +42,38 @@ public class BelowThresholdDetector extends Detector {
 
   private static final Logger LOG = Logger.getLogger(BelowThresholdDetector.class.getSimpleName());
 
-  @Inject
   public BelowThresholdDetector(PolicyConfig policyConfig, String metricName) {
-    this.lowThreshold = (Double) policyConfig.getConfig(Utils.getCompositeName(LOW_THRESHOLD_CONF, metricName));
-    this.noCheckpoints = (Double) policyConfig.getConfig(Utils.getCompositeName(BELOW_THRESHOLD_NO_CHECKPOINTS,
-                                                                                metricName), 1);
+    this.lowThreshold = (Double) policyConfig.getConfig(String.join("_", LOW_THRESHOLD_CONF, metricName));
+    this.noCheckpoints
+        = (Double) policyConfig.getConfig(String.join("_", BELOW_THRESHOLD_NO_CHECKPOINTS, metricName), 1);
     this.metricName = metricName;
   }
 
   @Override
   public Collection<Symptom> detect(Collection<Measurement> measurements) {
-    ArrayList<Symptom> result = new ArrayList<>();
-    if (measurements.size() > 0) {
+    if (measurements.isEmpty()) {
+      return Collections.emptyList();
+    }
+
     MeasurementsTable measurementsTable = context.measurements().type(metricName).sort(false, SortKey.TIME_STAMP);
-      Collection<String> belowThresholdAssignments = new ArrayList();
+    Collection<String> assignments = new ArrayList<>();
     for (String component : measurementsTable.uniqueComponents()) {
       MeasurementsTable componentData = measurementsTable.component(component);
       for (String instance : componentData.uniqueInstances()) {
-          MeasurementsTable instanceData = measurementsTable.instance(instance).last((int) noCheckpoints);
+        MeasurementsTable instanceData = componentData.instance(instance).last((int) noCheckpoints);
         if (instanceData.valueBetween(Double.MIN_VALUE, lowThreshold).size() == noCheckpoints) {
-            LOG.fine(String.format("Instance %s has values below the limit for the last %s checkpoints", instance,
-                                   noCheckpoints));
-            belowThresholdAssignments.add(instance);
+          LOG.fine(String.format("Instance %s has values below the limit %s for the last %s checkpoints",
+                                 instance, lowThreshold, noCheckpoints));
+          assignments.add(instance);
         }
       }
     }
-      if (belowThresholdAssignments.size() > 0) {
-        Symptom s = new Symptom(Utils.getCompositeName(SYMPTOM_LOW, metricName), context.checkpoint(),
-                                belowThresholdAssignments);
-        result.add(s);
+
+    if (assignments.isEmpty()) {
+      return Collections.emptyList();
     }
-    }
-    return result;
+
+    Symptom s = new Symptom(String.join("_", SYMPTOM_LOW, metricName), context.checkpoint(), assignments);
+    return Collections.singletonList(s);
   }
 }

src/main/java/com/microsoft/dhalion/detectors/Detector.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.detectors;
 
 import com.microsoft.dhalion.api.IDetector;
@@ -11,5 +18,4 @@ public class Detector implements IDetector {
   public void initialize(ExecutionContext context) {
     this.context = context;
   }
-
 }

src/main/java/com/microsoft/dhalion/examples/AlertPolicy.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.examples;
 
 import com.microsoft.dhalion.api.IHealthPolicy;

src/main/java/com/microsoft/dhalion/examples/AlertResolver.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.examples;
 
 import com.microsoft.dhalion.api.IResolver;

src/main/java/com/microsoft/dhalion/examples/CSVMetricsProvider.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.examples;
 
 import com.microsoft.dhalion.api.MetricsProvider;

src/main/java/com/microsoft/dhalion/examples/MetricName.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.examples;
 
 /**

src/main/java/com/microsoft/dhalion/examples/NodeStat.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.examples;
 
 import com.google.common.annotations.VisibleForTesting;

src/main/java/com/microsoft/dhalion/examples/UncommonUtilizationDiagnoser.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.examples;
 
 import com.microsoft.dhalion.Utils;

src/main/java/com/microsoft/dhalion/sensors/BasicSensor.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.sensors;
 
 import com.microsoft.dhalion.api.ISensor;

src/test/java/com/microsoft/dhalion/detectors/AboveThresholdDetectorTest.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.detectors;
 
 import com.microsoft.dhalion.Utils;

src/test/java/com/microsoft/dhalion/detectors/BelowThresholdDetectorTest.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.detectors;
 
 import com.microsoft.dhalion.Utils;

src/test/java/com/microsoft/dhalion/examples/CSVMetricsProviderTest.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.examples;
 
 import com.microsoft.dhalion.conf.Config;

src/test/java/com/microsoft/dhalion/examples/NodeStatTest.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.examples;
 
 import com.microsoft.dhalion.core.Measurement;

src/test/java/com/microsoft/dhalion/examples/UncommonUtilizationDiagnoserTest.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.examples;
 
 import com.microsoft.dhalion.Utils;

src/test/java/com/microsoft/dhalion/sensors/BasicSensorTest.java

@@ -1,3 +1,10 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ *
+ * This program is made available under the terms of the MIT License.
+ * See the LICENSE file in the project root for more information.
+ */
+
 package com.microsoft.dhalion.sensors;
 
 import com.microsoft.dhalion.api.MetricsProvider;