Added withEndpoint and filtering of Double.NaN

src/main/java/com/plausiblelabs/metrics/reporting/CloudWatchReporter.java

@@ -100,6 +100,17 @@ public Enabler(String namespace, AmazonCloudWatchClient client) {
             this.client = client;
         }
 
+        /**
+         * Sets the endpoint for the AmazonCloudWatchClient
+         *
+         * @param endpoint the region specific endpoint url. Must be non-null and not empty.
+         * @return this Enabler.
+         */
+        public Enabler withEndpoint(String endpoint) {
+            this.client.setEndpoint(endpoint);
+            return this;
+        }
+
         /**
          * <p>The histogram and meter percentiles to send. If <code>.5</code> is included, it'll be reported as
          * <code>median</code>.This defaults to <code>.5, .95, and .99</code>.
@@ -401,7 +412,7 @@ private void sendToCloudWatch() {
         }
     }
 
-    private boolean sentTooSmall, sentTooLarge;
+    private boolean sentTooSmall, sentTooLarge, sentNaN;
 
     private void sendValue(Date timestamp, String name, double value, StandardUnit unit, List<Dimension> dimensions) {
         double absValue = Math.abs(value);
@@ -427,7 +438,14 @@ private void sendValue(Date timestamp, String name, double value, StandardUnit u
                 LOG.debug("Value for {} is larger than what CloudWatch supports; trimming to {}. Further large values won't be logged.", name, value);
                 sentTooLarge = true;
             }
+        } else if (Double.isNaN(value)) {
+            if (!sentNaN) {
+                LOG.debug("Value for {} is NaN; setting to 0. Further NaN values won't be logged.", name, value);
+                sentNaN = true;
+            }
+            value = 0;
         }
+
         // TODO limit to 10 dimensions
         MetricDatum datum = new MetricDatum()
             .withTimestamp(timestamp)

src/test/java/com/plausiblelabs/metrics/reporting/CloudWatchReporterTest.java

@@ -23,7 +23,8 @@ public class CloudWatchReporterTest {
     private MetricsRegistry testRegistry = new MetricsRegistry();
     private DummyCloudWatchClient client = new DummyCloudWatchClient();
     private CloudWatchReporter.Enabler enabler =
-        new CloudWatchReporter.Enabler("testnamespace", client).withRegistry(testRegistry);
+        new CloudWatchReporter.Enabler("testnamespace", client).withRegistry(testRegistry)
+            .withEndpoint("monitoring.us-west-2.amazonaws.com");
 
     @After
     public void shutdownRegistry() {

src/test/java/com/plausiblelabs/metrics/reporting/RemoteCloudWatchTest.java

@@ -55,7 +55,13 @@ public Double value() {
                 return CloudWatchReporter.LARGEST_SENDABLE * 10;
             }
         });
-        new CloudWatchReporter.Enabler("cxabf", creds)
+        Metrics.newGauge(new MetricName("test", "limits", "NaN"), new Gauge<Double>() {
+            @Override
+            public Double value() {
+                return Double.NaN;
+            }
+        });
+        new CloudWatchReporter.Enabler("cxabf", creds).withEndpoint("monitoring.us-west-2.amazonaws.com")
             .withInstanceIdDimension("test").build().run();
 
     }