[FLINK-16686][State] Set classloader for compaction filters

flink-runtime/src/test/java/org/apache/flink/runtime/state/ttl/StateBackendTestContext.java

@@ -89,11 +89,12 @@ private CheckpointStreamFactory createCheckpointStreamFactory() {
         }
     }
 
-    public void createAndRestoreKeyedStateBackend(KeyedStateHandle snapshot) {
+    public void createAndRestoreKeyedStateBackend(KeyedStateHandle snapshot) throws IOException {
         createAndRestoreKeyedStateBackend(NUMBER_OF_KEY_GROUPS, snapshot);
     }
 
-    void createAndRestoreKeyedStateBackend(int numberOfKeyGroups, KeyedStateHandle snapshot) {
+    void createAndRestoreKeyedStateBackend(int numberOfKeyGroups, KeyedStateHandle snapshot)
+            throws IOException {
         Collection<KeyedStateHandle> stateHandles;
         if (snapshot == null) {
             stateHandles = Collections.emptyList();
@@ -102,6 +103,8 @@ void createAndRestoreKeyedStateBackend(int numberOfKeyGroups, KeyedStateHandle s
             stateHandles.add(snapshot);
         }
         env = MockEnvironment.builder().build();
+        env.setCheckpointStorageAccess(
+                createCheckpointStorage().createCheckpointStorage(new JobID()));
         try {
             disposeKeyedStateBackend();
             keyedStateBackend =

flink-runtime/src/test/java/org/apache/flink/runtime/state/ttl/TtlListStateWithKryoTestContext.java

@@ -0,0 +1,92 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.runtime.state.ttl;
+
+import org.apache.flink.api.common.serialization.SerializerConfig;
+import org.apache.flink.api.common.serialization.SerializerConfigImpl;
+import org.apache.flink.api.java.typeutils.runtime.kryo.KryoSerializer;
+import org.apache.flink.configuration.Configuration;
+import org.apache.flink.configuration.PipelineOptions;
+
+import java.util.Arrays;
+import java.util.Collections;
+
+/** Test suite for {@link TtlListState} with elements of serialized by kryo. */
+public class TtlListStateWithKryoTestContext
+        extends TtlListStateTestContextBase<TtlListStateWithKryoTestContext.NotPojoElement> {
+    TtlListStateWithKryoTestContext() {
+        super(new KryoSerializer<>(NotPojoElement.class, getForceKryoSerializerConfig()));
+    }
+
+    private static SerializerConfig getForceKryoSerializerConfig() {
+        Configuration config = new Configuration();
+        config.set(PipelineOptions.FORCE_KRYO, true);
+        return new SerializerConfigImpl(config);
+    }
+
+    @Override
+    NotPojoElement generateRandomElement(int i) {
+        return new NotPojoElement(RANDOM.nextInt(100));
+    }
+
+    @Override
+    void initTestValues() {
+        emptyValue = Collections.emptyList();
+
+        updateEmpty =
+                Arrays.asList(new NotPojoElement(5), new NotPojoElement(7), new NotPojoElement(10));
+        updateUnexpired =
+                Arrays.asList(new NotPojoElement(8), new NotPojoElement(9), new NotPojoElement(11));
+        updateExpired = Arrays.asList(new NotPojoElement(1), new NotPojoElement(4));
+
+        getUpdateEmpty = updateEmpty;
+        getUnexpired = updateUnexpired;
+        getUpdateExpired = updateExpired;
+    }
+
+    public static class NotPojoElement {
+        public int value;
+
+        public NotPojoElement(int value) {
+            this.value = value;
+        }
+
+        @Override
+        public String toString() {
+            return "NotPojoElement{" + "value=" + value + '}';
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj == null || getClass() != obj.getClass()) {
+                return false;
+            }
+            NotPojoElement that = (NotPojoElement) obj;
+            return value == that.value;
+        }
+
+        @Override
+        public int hashCode() {
+            return Integer.hashCode(value);
+        }
+    }
+}

flink-runtime/src/test/java/org/apache/flink/runtime/state/ttl/TtlStateTestBase.java

@@ -85,6 +85,7 @@ protected abstract StateBackendTestContext createStateBackendTestContext(
                 new TtlValueStateTestContext(),
                 new TtlFixedLenElemListStateTestContext(),
                 new TtlNonFixedLenElemListStateTestContext(),
+                new TtlListStateWithKryoTestContext(),
                 new TtlMapStateAllEntriesTestContext(),
                 new TtlMapStatePerElementTestContext(),
                 new TtlMapStatePerNullElementTestContext(),

flink-state-backends/flink-statebackend-forst/src/main/java/org/apache/flink/state/forst/ForStDBTtlCompactFiltersManager.java

@@ -48,6 +48,7 @@
 import java.io.IOException;
 import java.time.Duration;
 import java.util.LinkedHashMap;
+import java.util.function.Supplier;
 
 /** RocksDB compaction filter utils for state with TTL. */
 public class ForStDBTtlCompactFiltersManager {
@@ -205,15 +206,27 @@ public void configCompactFilter(
 
     private static class ListElementFilterFactory<T>
             implements FlinkCompactionFilter.ListElementFilterFactory {
-        private final TypeSerializer<T> serializer;
+        // {@See #createListElementFilter}.
+        private final ThreadLocalSerializerProvider<T> threadLocalSerializer;
 
         private ListElementFilterFactory(TypeSerializer<T> serializer) {
-            this.serializer = serializer;
+            ClassLoader contextClassLoader = null;
+            try {
+                contextClassLoader = Thread.currentThread().getContextClassLoader();
+            } catch (Throwable e) {
+                LOG.info("Cannot get context classloader for list state's compaction filter.", e);
+            }
+            threadLocalSerializer =
+                    new ThreadLocalSerializerProvider<>(serializer, contextClassLoader);
         }
 
         @Override
         public FlinkCompactionFilter.ListElementFilter createListElementFilter() {
-            return new ListElementFilter<>(serializer);
+            // This method will be invoked by native code multiple times when creating compaction
+            // filter. And the created filter will be shared by multiple background threads.
+            // Make sure the serializer is thread-local and has classloader set for each thread
+            // correctly and individually.
+            return new ListElementFilter<>(threadLocalSerializer);
         }
     }
 
@@ -231,21 +244,22 @@ public long currentTimestamp() {
     }
 
     private static class ListElementFilter<T> implements FlinkCompactionFilter.ListElementFilter {
-        private final TypeSerializer<T> serializer;
-        private DataInputDeserializer input;
+        private final ThreadLocalSerializerProvider<T> threadLocalSerializer;
+        private final DataInputDeserializer input;
 
-        private ListElementFilter(TypeSerializer<T> serializer) {
-            this.serializer = serializer;
+        private ListElementFilter(ThreadLocalSerializerProvider<T> serializer) {
+            this.threadLocalSerializer = serializer;
             this.input = new DataInputDeserializer();
         }
 
         @Override
         public int nextUnexpiredOffset(byte[] bytes, long ttl, long currentTimestamp) {
             input.setBuffer(bytes);
             int lastElementOffset = 0;
+            TypeSerializer<T> serializer = threadLocalSerializer.get();
             while (input.available() > 0) {
                 try {
-                    long timestamp = nextElementLastAccessTimestamp();
+                    long timestamp = nextElementLastAccessTimestamp(serializer);
                     if (!TtlUtils.expired(timestamp, ttl, currentTimestamp)) {
                         break;
                     }
@@ -258,7 +272,8 @@ public int nextUnexpiredOffset(byte[] bytes, long ttl, long currentTimestamp) {
             return lastElementOffset;
         }
 
-        private long nextElementLastAccessTimestamp() throws IOException {
+        private long nextElementLastAccessTimestamp(TypeSerializer<T> serializer)
+                throws IOException {
             TtlValue<?> ttlValue = (TtlValue<?>) serializer.deserialize(input);
             if (input.available() > 0) {
                 input.skipBytesToRead(1);
@@ -267,6 +282,37 @@ private long nextElementLastAccessTimestamp() throws IOException {
         }
     }
 
+    private static class ThreadLocalSerializerProvider<T> implements Supplier<TypeSerializer<T>> {
+        // Multiple background threads may share the same filter instance, so we need to make sure
+        // the serializer is thread-local, and every thread has its own instance with classloader.
+        private final ThreadLocal<TypeSerializer<T>> threadLocalSerializer;
+
+        public ThreadLocalSerializerProvider(
+                TypeSerializer<T> serializer, ClassLoader classLoader) {
+            this.threadLocalSerializer =
+                    ThreadLocal.withInitial(
+                            () -> {
+                                setClassloaderIfNeeded(classLoader);
+                                return serializer.duplicate();
+                            });
+        }
+
+        private void setClassloaderIfNeeded(ClassLoader classLoader) {
+            // The classloader that should be set to the current thread when deserializing.
+            // The reason why we should set classloader is that the serializer may be Kryo
+            // serializer which needs user classloader to load user classes.
+            // See FLINK-16686 for more details.
+            if (classLoader != null) {
+                Thread.currentThread().setContextClassLoader(classLoader);
+            }
+        }
+
+        @Override
+        public TypeSerializer<T> get() {
+            return threadLocalSerializer.get();
+        }
+    }
+
     public void disposeAndClearRegisteredCompactionFactories() {
         for (FlinkCompactionFilterFactory factory : compactionFilterFactories.values()) {
             IOUtils.closeQuietly(factory);

flink-state-backends/flink-statebackend-forst/src/main/java/org/apache/flink/state/forst/sync/ForStSyncKeyedStateBackend.java

@@ -74,6 +74,7 @@
 import org.forstdb.ColumnFamilyOptions;
 import org.forstdb.ReadOptions;
 import org.forstdb.RocksDB;
+import org.forstdb.RocksDBException;
 import org.forstdb.Snapshot;
 import org.forstdb.WriteOptions;
 import org.slf4j.Logger;
@@ -944,6 +945,13 @@ public boolean isSafeToReuseKVState() {
         return true;
     }
 
+    @VisibleForTesting
+    public void compactState(StateDescriptor<?, ?> stateDesc) throws RocksDBException {
+        ForStOperationUtils.ForStKvStateInfo kvStateInfo =
+                kvStateInformation.get(stateDesc.getName());
+        db.compactRange(kvStateInfo.columnFamilyHandle);
+    }
+
     @Nonnegative
     long getWriteBatchSize() {
         return writeBatchSize;