make timestamp more user friendly when reading

Signed-off-by: Jackie <jkhanjob@gmail.com>

Author: jackiehanyang

build.gradle

@@ -220,7 +220,7 @@ tasks.register('prepareJacocoAgent', Copy) {
 // to prevent duplicate -javaagent entries.
 tasks.named('test', Test) {
     // Disable Gradle's default Jacoco injection to avoid transient agent path issues
-    jacoco.enabled = false
+    jacoco.enabled = true
     // Ensure OpenSearch bytecode agent is not attached to unit tests
     // Build a classpath that prefers main/test outputs and external deps over the shaded jar
     classpath = files(
@@ -232,7 +232,8 @@ tasks.named('test', Test) {
         // Remove any opensearch-agent -javaagent from jvmArgs if present
         def before = jvmArgs == null ? [] : new ArrayList<String>(jvmArgs)
         if (before) {
-            def filtered = before.findAll { !(it instanceof String && it.contains('opensearch-agent')) && !(it instanceof String && it.startsWith('-javaagent:')) }
+            // Only strip the OpenSearch java agent; keep Jacoco agent intact
+            def filtered = before.findAll { !(it instanceof String && it.contains('opensearch-agent')) }
             if (filtered.size() != before.size()) {
                 jvmArgs = filtered
             }
@@ -440,6 +441,7 @@ task integTest(type: RestIntegTestTask) {
 tasks.named("check").configure { dependsOn(integTest) }
 
 integTest {
+    jacoco.enabled = true
     retry {
         if (BuildParams.isCi()) {
             maxRetries = 6
@@ -1162,6 +1164,15 @@ jacocoTestCoverageVerification {
 check.dependsOn jacocoTestCoverageVerification
 jacocoTestCoverageVerification.dependsOn jacocoTestReport
 
+jacocoTestReport {
+    dependsOn test, integTest
+    executionData.from = files(test.jacoco.destinationFile, integTest.jacoco.destinationFile)
+    reports {
+        xml.required = true
+        html.required = true
+    }
+}
+
 compileJava.options.compilerArgs << "-Xlint:-deprecation,-rawtypes,-serial,-try,-unchecked"
 
 apply plugin: 'com.netflix.nebula.ospackage'

src/main/java/org/opensearch/ad/ml/InsightsGenerator.java

@@ -7,6 +7,8 @@
 
 import java.io.IOException;
 import java.time.Instant;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -215,6 +217,13 @@ private static String generateParagraphText(
     ) {
         StringBuilder text = new StringBuilder();
 
+        DateTimeFormatter friendlyFormatter = DateTimeFormatter
+            .ofPattern("MMM d, yyyy HH:mm z")
+            .withLocale(Locale.ROOT)
+            .withZone(ZoneOffset.UTC);
+        String startStr = friendlyFormatter.format(eventStart);
+        String endStr = friendlyFormatter.format(eventEnd);
+
         text.append(String.format(Locale.ROOT, "Correlated anomalies detected across %d detector(s)", detectorIds.size()));
 
         if (!indices.isEmpty()) {
@@ -226,8 +235,9 @@ private static String generateParagraphText(
         }
 
         text.append(".");
-
-        text.append(String.format(Locale.ROOT, " Detected from %s to %s with %d correlated metrics.", eventStart, eventEnd, numMetrics));
+        text.append(
+            String.format(Locale.ROOT, " Detected from %s to %s with %d correlated metrics.", startStr, endStr, numMetrics)
+        );
 
         return text.toString();
     }