[FLINK-37370] [Observer] Finished batch jobs throw ReconciliationException and never reach FINISHED in the CR

flink-kubernetes-operator/src/main/java/org/apache/flink/kubernetes/operator/observer/SnapshotObserver.java

@@ -441,7 +441,6 @@ private long getMaxCountForSnapshotType(
     }
 
     private void observeLatestCheckpoint(FlinkResourceContext<CR> ctx, String jobId) {
-
         var status = ctx.getResource().getStatus();
         var jobStatus = status.getJobStatus();
 

flink-kubernetes-operator/src/main/java/org/apache/flink/kubernetes/operator/service/AbstractFlinkService.java

@@ -546,6 +546,12 @@ public Optional<Savepoint> getLastCheckpoint(JobID jobId, Configuration conf) {
         try {
             latestCheckpointOpt = getCheckpointInfo(jobId, conf).f0;
         } catch (Exception e) {
+            if (e instanceof RestClientException
+                    && e.getMessage() != null
+                    && e.getMessage().contains("Checkpointing has not been enabled")) {
+                LOG.warn("Checkpointing not enabled for job {}", jobId, e);
+                return Optional.empty();
+            }
             throw new ReconciliationException("Could not observe latest savepoint information", e);
         }
 

flink-kubernetes-operator/src/test/java/org/apache/flink/kubernetes/operator/TestingFlinkService.java

@@ -138,6 +138,7 @@ public class TestingFlinkService extends AbstractFlinkService {
     @Getter private final Map<String, Boolean> savepointTriggers = new HashMap<>();
     @Getter private final Map<String, Boolean> checkpointTriggers = new HashMap<>();
     private final Map<Long, String> checkpointStats = new HashMap<>();
+    @Setter private boolean throwCheckpointingDisabledError = false;
 
     @Getter private int desiredReplicas = 0;
     @Getter private int cancelJobCallCount = 0;
@@ -593,6 +594,10 @@ public Optional<Savepoint> getLastCheckpoint(JobID jobId, Configuration conf) {
                     Optional<CheckpointHistoryWrapper.CompletedCheckpointInfo>,
                     Optional<CheckpointHistoryWrapper.PendingCheckpointInfo>>
             getCheckpointInfo(JobID jobId, Configuration conf) throws Exception {
+        if (throwCheckpointingDisabledError) {
+            throw new RestClientException(
+                    "Checkpointing has not been enabled", HttpResponseStatus.BAD_REQUEST);
+        }
 
         if (checkpointInfo != null) {
             return checkpointInfo;

flink-kubernetes-operator/src/test/java/org/apache/flink/kubernetes/operator/observer/deployment/ApplicationObserverTest.java

@@ -898,4 +898,35 @@ public void jobStatusNotOverwrittenWhenTerminal() throws Exception {
                 org.apache.flink.api.common.JobStatus.FINISHED,
                 deployment.getStatus().getJobStatus().getState());
     }
+
+    @Test
+    public void getLastCheckpointShouldHandleCheckpointingNotEnabled() throws Exception {
+        Configuration conf =
+                configManager.getDeployConfig(deployment.getMetadata(), deployment.getSpec());
+        flinkService.submitApplicationCluster(deployment.getSpec().getJob(), conf, false);
+        bringToReadyStatus(deployment);
+
+        deployment
+                .getStatus()
+                .getJobStatus()
+                .setState(org.apache.flink.api.common.JobStatus.FINISHED);
+        var jobs = flinkService.listJobs();
+        var oldStatus = jobs.get(0).f1;
+        jobs.get(0).f1 =
+                new JobStatusMessage(
+                        oldStatus.getJobId(),
+                        oldStatus.getJobName(),
+                        org.apache.flink.api.common.JobStatus.FINISHED,
+                        oldStatus.getStartTime());
+
+        flinkService.setThrowCheckpointingDisabledError(true);
+        observer.observe(deployment, readyContext);
+
+        assertEquals(
+                0,
+                countErrorEvents(
+                        EventRecorder.Reason.CheckpointError.name(),
+                        deployment.getMetadata().getNamespace(),
+                        "Checkpointing has not been enabled"));
+    }
 }