[ML] adds latest record timestamp to model snapshot deprecation warning (#73066) (#73213)

This adds the latest record timestamp of the deprecated model snapshot in the warning.

This hopefully gives the user a better view into whether they would want to delete the snapshot or to upgrade it.

Author: benwtrent

x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/MlDeprecationChecker.java

@@ -11,6 +11,7 @@
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.NamedXContentRegistry;
+import org.elasticsearch.common.xcontent.XContentElasticsearchExtension;
 import org.elasticsearch.xpack.core.XPackSettings;
 import org.elasticsearch.xpack.core.action.util.PageParams;
 import org.elasticsearch.xpack.core.deprecation.DeprecationIssue;
@@ -53,6 +54,20 @@ static Optional<DeprecationIssue> checkDataFeedAggregations(DatafeedConfig dataf
 
     static Optional<DeprecationIssue> checkModelSnapshot(ModelSnapshot modelSnapshot) {
         if (modelSnapshot.getMinVersion().before(Version.V_7_0_0)) {
+            StringBuilder details = new StringBuilder(String.format(
+                Locale.ROOT,
+                "model snapshot [%s] for job [%s] supports minimum version [%s] and needs to be at least [%s].",
+                modelSnapshot.getSnapshotId(),
+                modelSnapshot.getJobId(),
+                modelSnapshot.getMinVersion(),
+                Version.V_7_0_0));
+            if (modelSnapshot.getLatestRecordTimeStamp() != null) {
+                details.append(String.format(
+                    Locale.ROOT,
+                    " The model snapshot's latest record timestamp is [%s]",
+                    XContentElasticsearchExtension.DEFAULT_DATE_PRINTER.print(modelSnapshot.getLatestRecordTimeStamp().getTime())
+                ));
+            }
             return Optional.of(new DeprecationIssue(DeprecationIssue.Level.CRITICAL,
                 String.format(
                     Locale.ROOT,
@@ -61,15 +76,9 @@ static Optional<DeprecationIssue> checkModelSnapshot(ModelSnapshot modelSnapshot
                     modelSnapshot.getJobId()
                 ),
                 "https://www.elastic.co/guide/en/elasticsearch/reference/master/ml-upgrade-job-model-snapshot.html",
-               String.format(
-                   Locale.ROOT,
-                   "model snapshot [%s] for job [%s] supports minimum version [%s] and needs to be at least [%s]",
-                   modelSnapshot.getSnapshotId(),
-                   modelSnapshot.getJobId(),
-                   modelSnapshot.getMinVersion(),
-                   Version.V_7_0_0
+                details.toString()
                )
-            ));
+            );
         }
         return Optional.empty();
     }