Modified metrics validation logic and minor fixes

Author: Meshwa Savalia

README.md

@@ -92,7 +92,7 @@ The `MetricsLogger` is the interface you will use to publish embedded metrics.
 - MetricsLogger **putMetric**(String key, double value, Unit unit)
 - MetricsLogger **putMetric**(String key, double value)
 
-Adds a new metric to the current logger context. Multiple metrics using the same key will be appended to an array of values. Multiple metrics cannot have same key but different storage resolution. The Embedded Metric Format supports a maximum of 100 values per key.
+Adds a new metric to the current logger context. Multiple metrics using the same key will be appended to an array of values. Multiple metrics cannot have same key and different storage resolution. The Embedded Metric Format supports a maximum of 100 values per key.
 
 Requirements:
 

canarytests/agent/src/main/java/emf/canary/ECSRunnable.java

@@ -8,6 +8,7 @@
 import software.amazon.cloudwatchlogs.emf.exception.InvalidNamespaceException;
 import software.amazon.cloudwatchlogs.emf.logger.MetricsLogger;
 import software.amazon.cloudwatchlogs.emf.model.DimensionSet;
+import software.amazon.cloudwatchlogs.emf.model.StorageResolution;
 import software.amazon.cloudwatchlogs.emf.model.Unit;
 
 import java.lang.management.ManagementFactory;
@@ -46,7 +47,7 @@ public void run() {
         try {
             logger.putMetric("Invoke", 1, Unit.COUNT);
             logger.putMetric("Memory.HeapTotal", heapTotal, Unit.COUNT);
-            logger.putMetric("Memory.HeapUsed", heapUsed, Unit.COUNT);
+            logger.putMetric("Memory.HeapUsed", heapUsed, Unit.COUNT, StorageResolution.HIGH);
             logger.putMetric("Memory.JVMUsedTotal", heapUsed + nonHeapUsed, Unit.COUNT);
         } catch (InvalidMetricException e) {
             System.out.println(e);

examples/ecs-firelens/src/main/java/App.java

@@ -40,7 +40,7 @@ public static void main(String[] args) throws Exception {
         MetricsLogger logger = new MetricsLogger();
         logger.setNamespace("FargateEMF");
         logger.putMetric("Latency", 63, Unit.MILLISECONDS);
-        logger.putMetric("LatencyInHighResolution", 65, Unit.MILLISECONDS, StorageResolution.HIGH);
+        logger.putMetric("CPU Utilization", 87, Unit.PERCENT, StorageResolution.HIGH);
         logger.flush();
         HttpServer server = HttpServer.create(new InetSocketAddress(8000), 0);
         int portNumber = 8000;
@@ -77,7 +77,6 @@ public void handle(HttpExchange he) throws IOException {
             logger.putProperty("Url", he.getRequestURI());
             try {
                 logger.putMetric("ProcessingTime", System.currentTimeMillis() - time, Unit.MILLISECONDS);
-                logger.putMetric("ProcessingTimeInHighResolution", System.currentTimeMillis() - time, Unit.MILLISECONDS, StorageResolution.HIGH);
             } catch (InvalidMetricException e) {
                 System.out.println(e);
             }

examples/lambda/src/main/java/Handler.java

@@ -21,7 +21,7 @@ public String handleRequest(Map<String, String> event, Context context) {
         try {
             logger.putDimensions(DimensionSet.of("Service", "Aggregator"));
             logger.putMetric("ProcessingLatency", 100, Unit.MILLISECONDS);
-            logger.putMetric("ProcessingLatencyInHighResolution", 101, Unit.MILLISECONDS, StorageResolution.HIGH);
+            logger.putMetric("CPU Utilization", 87, Unit.PERCENT, StorageResolution.HIGH);
         } catch (InvalidDimensionException | InvalidMetricException | DimensionSetExceededException e) {
             System.out.println(e);
         }

src/main/java/software/amazon/cloudwatchlogs/emf/logger/MetricsLogger.java

@@ -35,7 +35,6 @@
 import software.amazon.cloudwatchlogs.emf.model.StorageResolution;
 import software.amazon.cloudwatchlogs.emf.model.Unit;
 import software.amazon.cloudwatchlogs.emf.sinks.ISink;
-import software.amazon.cloudwatchlogs.emf.util.Validator;
 
 /**
  * A metrics logger. Use this interface to publish logs to CloudWatch Logs and extract metrics to
@@ -94,7 +93,6 @@ public void flush() {
             configureContextForEnvironment(context, environment);
             sink.accept(context);
             context = context.createCopyWithContext(flushPreserveDimensions);
-            Validator.metricNameAndResolutionMap.clear();
         } finally {
             rwl.writeLock().unlock();
         }
@@ -193,6 +191,9 @@ public MetricsLogger resetDimensions(boolean useDefault) {
      * @param value is the value of the metric
      * @param unit is the unit of the metric value
      * @param storageResolution is the resolution of the metric
+     * @see <a
+     *     href="https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/publishingMetrics.html#high-resolution-metrics">CloudWatch
+     *     High Resolution Metrics</a>
      * @return the current logger
      * @throws InvalidMetricException if the metric is invalid
      */
@@ -216,6 +217,9 @@ public MetricsLogger putMetric(
      * @param key is the name of the metric
      * @param value is the value of the metric
      * @param storageResolution is the resolution of the metric
+     * @see <a
+     *     href="https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/publishingMetrics.html#high-resolution-metrics">CloudWatch
+     *     High Resolution Metrics</a>
      * @return the current logger
      * @throws InvalidMetricException if the metric is invalid
      */

src/main/java/software/amazon/cloudwatchlogs/emf/model/MetricsContext.java

@@ -34,6 +34,7 @@ public class MetricsContext {
     @Getter private final RootNode rootNode;
 
     private MetricDirective metricDirective;
+    private final Map<String, String> metricNameAndResolutionMap = new HashMap<>();
 
     public MetricsContext() {
         this(new RootNode());
@@ -119,7 +120,7 @@ public boolean hasDefaultDimensions() {
      */
     public void putMetric(String key, double value, Unit unit, StorageResolution storageResolution)
             throws InvalidMetricException {
-        Validator.validateMetric(key, value, unit, storageResolution);
+        Validator.validateMetric(key, value, unit, storageResolution, metricNameAndResolutionMap);
         metricDirective.putMetric(key, value, unit, storageResolution);
     }
     /**

src/main/java/software/amazon/cloudwatchlogs/emf/serializers/StorageResolutionFilter.java

@@ -7,7 +7,7 @@ public class StorageResolutionFilter {
     @Override
     public boolean equals(Object obj) {
 
-        if (obj == null || !(obj instanceof StorageResolution)) {
+        if (!(obj instanceof StorageResolution)) {
             return false;
         }
         return (obj.toString().equals("STANDARD"));

src/main/java/software/amazon/cloudwatchlogs/emf/util/Validator.java

@@ -17,7 +17,6 @@
 package software.amazon.cloudwatchlogs.emf.util;
 
 import java.time.Instant;
-import java.util.HashMap;
 import java.util.Map;
 import org.apache.commons.lang3.StringUtils;
 import software.amazon.cloudwatchlogs.emf.Constants;
@@ -26,7 +25,6 @@
 import software.amazon.cloudwatchlogs.emf.model.Unit;
 
 public class Validator {
-    public static Map<String, String> metricNameAndResolutionMap = new HashMap<>();
 
     private Validator() {
         throw new IllegalStateException("Utility class");
@@ -94,10 +92,15 @@ public static void validateDimensionSet(String dimensionName, String dimensionVa
      * @param value Metric value
      * @param unit Metric unit
      * @param storageResolution Metric resolution
+     * @param metricNameAndResolutionMap Map to validate Metric
      * @throws InvalidMetricException if metric is invalid
      */
     public static void validateMetric(
-            String name, double value, Unit unit, StorageResolution storageResolution)
+            String name,
+            double value,
+            Unit unit,
+            StorageResolution storageResolution,
+            Map<String, String> metricNameAndResolutionMap)
             throws InvalidMetricException {
 
         if (name == null || name.trim().isEmpty()) {
@@ -126,8 +129,7 @@ public static void validateMetric(
         }
 
         if (metricNameAndResolutionMap.containsKey(name)) {
-            String resolutionOfMetric = metricNameAndResolutionMap.get(name);
-            if (!resolutionOfMetric.equals(storageResolution.toString())) {
+            if (!metricNameAndResolutionMap.get(name).equals(storageResolution.toString())) {
                 throw new InvalidMetricException(
                         "Resolution for metrics "
                                 + name

src/test/java/software/amazon/cloudwatchlogs/emf/logger/MetricsLoggerTest.java

@@ -361,6 +361,16 @@ void whenPutMetric_withNullStorageResolution_thenThrowInvalidMetricException() {
                 () -> logger.putMetric("test", 1, (StorageResolution) null));
     }
 
+    @Test
+    void whenPutMetric_withSameMetricDifferentStorageResolutionAfterFlush_thenAllow()
+            throws InvalidMetricException {
+        logger.putMetric("Count", 1);
+        logger.flush();
+        logger.putMetric("Count", 1.0, StorageResolution.HIGH);
+        logger.flush();
+        assertTrue(sink.getLogEvents().get(0).contains("StorageResolution"));
+    }
+
     @Test
     void whenPutMetric_withDifferentStorageResolution_thenThrowInvalidMetricException() {
         assertThrows(

src/test/java/software/amazon/cloudwatchlogs/emf/model/MetricDefinitionTest.java

@@ -31,6 +31,27 @@ public void testThrowExceptionIfNameIsNull() {
         new MetricDefinition(null);
     }
 
+    @Test
+    public void testSerializeMetricDefinitionWithoutUnitWithStorageResolution()
+            throws JsonProcessingException {
+        ObjectMapper objectMapper = new ObjectMapper();
+        MetricDefinition metricDefinition =
+                new MetricDefinition("Time", StorageResolution.HIGH, 10);
+        String metricString = objectMapper.writeValueAsString(metricDefinition);
+
+        assertEquals("{\"Name\":\"Time\",\"Unit\":\"None\",\"StorageResolution\":1}", metricString);
+    }
+
+    @Test
+    public void testSerializeMetricDefinitionWithUnitWithoutStorageResolution()
+            throws JsonProcessingException {
+        ObjectMapper objectMapper = new ObjectMapper();
+        MetricDefinition metricDefinition = new MetricDefinition("Time", Unit.MILLISECONDS, 10);
+        String metricString = objectMapper.writeValueAsString(metricDefinition);
+
+        assertEquals("{\"Name\":\"Time\",\"Unit\":\"Milliseconds\"}", metricString);
+    }
+
     @Test
     public void testSerializeMetricDefinitionWithoutUnit() throws JsonProcessingException {
         ObjectMapper objectMapper = new ObjectMapper();
@@ -43,10 +64,13 @@ public void testSerializeMetricDefinitionWithoutUnit() throws JsonProcessingExce
     @Test
     public void testSerializeMetricDefinition() throws JsonProcessingException {
         ObjectMapper objectMapper = new ObjectMapper();
-        MetricDefinition metricDefinition = new MetricDefinition("Time", Unit.MILLISECONDS, 10);
+        MetricDefinition metricDefinition =
+                new MetricDefinition("Time", Unit.MILLISECONDS, StorageResolution.HIGH, 10);
         String metricString = objectMapper.writeValueAsString(metricDefinition);
 
-        assertEquals("{\"Name\":\"Time\",\"Unit\":\"Milliseconds\"}", metricString);
+        assertEquals(
+                "{\"Name\":\"Time\",\"Unit\":\"Milliseconds\",\"StorageResolution\":1}",
+                metricString);
     }
 
     @Test