fredia commented on code in PR #20313:
URL: https://github.com/apache/flink/pull/20313#discussion_r925114799


##########
flink-runtime/src/main/java/org/apache/flink/runtime/state/SharedStateRegistryImpl.java:
##########
@@ -162,7 +174,14 @@ public Set<Long> unregisterUnusedState(long 
lowestCheckpointID) {
                         subsumed.add(entry.stateHandle);
                     }
                     it.remove();
-                } else {
+                } else if (preventsDiscardingCreatedCheckpoint(entry)) {

Review Comment:
   `lowestCheckpointID`  is the lowest checkpoint in use,  we should add 
`lowestCheckpointID` into `checkpointInUse` set **in theory**.  And it would 
not violate correctness now, because 
`CheckpointsCleaner#cleanSubsumedCheckpoints` would check `<upTo` again.
   
   



##########
flink-runtime/src/test/java/org/apache/flink/runtime/state/SharedStateRegistryTest.java:
##########
@@ -182,20 +194,113 @@ public void testRegisterChangelogStateBackendHandles() 
throws InterruptedExcepti
     }
 
     @Test
-    public void testUnregisterUnusedState() {
+    public void testUnregisterUnusedSavepointState() {
         SharedStateRegistry sharedStateRegistry = new 
SharedStateRegistryImpl();
         TestingStreamStateHandle handle = new TestingStreamStateHandle();
-        sharedStateRegistry.registerReference(new 
SharedStateRegistryKey("first"), handle, 1L);
-        sharedStateRegistry.registerReference(new 
SharedStateRegistryKey("first"), handle, 2L);
-        sharedStateRegistry.registerReference(new 
SharedStateRegistryKey("first"), handle, 3L);
+
+        registerInitialCheckpoint(
+                sharedStateRegistry,
+                RESTORED_STATE_ID,
+                CheckpointProperties.forSavepoint(false, 
SavepointFormatType.NATIVE));
+
+        sharedStateRegistry.registerReference(
+                new SharedStateRegistryKey(RESTORED_STATE_ID), handle, 2L);
+        sharedStateRegistry.registerReference(
+                new SharedStateRegistryKey(RESTORED_STATE_ID), handle, 3L);
+        sharedStateRegistry.registerReference(
+                new SharedStateRegistryKey("new-state"), new 
TestingStreamStateHandle(), 4L);
+
+        assertEquals(
+                "Only the initial checkpoint should be retained because its 
state is in use",
+                singleton(1L),
+                sharedStateRegistry.unregisterUnusedState(3));
+        assertTrue(
+                "The initial checkpoint state is unused so it could be 
discarded",
+                sharedStateRegistry.unregisterUnusedState(4).isEmpty());
+    }
+
+    @Test
+    public void testUnregisterInitialCheckpoint() {
+        SharedStateRegistry sharedStateRegistry = new 
SharedStateRegistryImpl();
+        TestingStreamStateHandle handle = new TestingStreamStateHandle();
+
+        registerInitialCheckpoint(
+                sharedStateRegistry,
+                RESTORED_STATE_ID,
+                CheckpointProperties.forCheckpoint(RETAIN_ON_CANCELLATION));
+
         sharedStateRegistry.registerReference(
-                new SharedStateRegistryKey("second"), new 
TestingStreamStateHandle(), 4L);
-        Set<Long> stillInUse = sharedStateRegistry.unregisterUnusedState(3);
-        Set<Long> expectedInUse = new HashSet<>(Arrays.asList(1L, 4L));
-        assertEquals(expectedInUse, stillInUse);
+                new SharedStateRegistryKey(RESTORED_STATE_ID), handle, 2L);
+
+        assertTrue(
+                "(retained) checkpoint - should NOT be considered in use even 
if its state is in use",
+                sharedStateRegistry.unregisterUnusedState(2).isEmpty());
+    }
+
+    /** Emulate turning changelog on while recovering from a retained 
checkpoint. */
+    @Test
+    public void testUnregisterInitialCheckpointUsedInChangelog() {
+        SharedStateRegistry sharedStateRegistry = new 
SharedStateRegistryImpl();
+        TestingStreamStateHandle handle = new TestingStreamStateHandle();
+
+        // "normal" restored checkpoint
+        registerInitialCheckpoint(
+                sharedStateRegistry,
+                RESTORED_STATE_ID,
+                CheckpointProperties.forCheckpoint(RETAIN_ON_CANCELLATION));

Review Comment:
   How to assign this `CheckpointProperties` to the restored checkpoint of 
changelog?
   
   We can‘t distinguish whether one checkpoint is restored or not 
in`ChangelogStateBackendHandle#registerSharedStates()`.
   
   Maybe we can do this in `CheckpointCoordinator(JM)`, but this method make JM 
know changelog.



##########
flink-runtime/src/test/java/org/apache/flink/runtime/state/SharedStateRegistryTest.java:
##########
@@ -182,20 +194,113 @@ public void testRegisterChangelogStateBackendHandles() 
throws InterruptedExcepti
     }
 
     @Test
-    public void testUnregisterUnusedState() {
+    public void testUnregisterUnusedSavepointState() {
         SharedStateRegistry sharedStateRegistry = new 
SharedStateRegistryImpl();
         TestingStreamStateHandle handle = new TestingStreamStateHandle();
-        sharedStateRegistry.registerReference(new 
SharedStateRegistryKey("first"), handle, 1L);
-        sharedStateRegistry.registerReference(new 
SharedStateRegistryKey("first"), handle, 2L);
-        sharedStateRegistry.registerReference(new 
SharedStateRegistryKey("first"), handle, 3L);
+
+        registerInitialCheckpoint(
+                sharedStateRegistry,
+                RESTORED_STATE_ID,
+                CheckpointProperties.forSavepoint(false, 
SavepointFormatType.NATIVE));
+
+        sharedStateRegistry.registerReference(
+                new SharedStateRegistryKey(RESTORED_STATE_ID), handle, 2L);
+        sharedStateRegistry.registerReference(
+                new SharedStateRegistryKey(RESTORED_STATE_ID), handle, 3L);
+        sharedStateRegistry.registerReference(
+                new SharedStateRegistryKey("new-state"), new 
TestingStreamStateHandle(), 4L);
+
+        assertEquals(
+                "Only the initial checkpoint should be retained because its 
state is in use",
+                singleton(1L),
+                sharedStateRegistry.unregisterUnusedState(3));
+        assertTrue(
+                "The initial checkpoint state is unused so it could be 
discarded",
+                sharedStateRegistry.unregisterUnusedState(4).isEmpty());

Review Comment:
   If "new-state" of  checkpoint-4 is still in use by subsequent checkpoints, 
checkpoint-4 also should be discarded, right?
   
   How about adding this check here?



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org

Reply via email to