Github user sihuazhou commented on a diff in the pull request:
https://github.com/apache/flink/pull/5239#discussion_r168189852
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/state/TaskLocalStateStoreImpl.java
---
@@ -0,0 +1,298 @@
+/*
+ * 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;
+
+import org.apache.flink.annotation.VisibleForTesting;
+import org.apache.flink.api.common.JobID;
+import org.apache.flink.core.fs.FileSystem;
+import org.apache.flink.core.fs.Path;
+import org.apache.flink.runtime.checkpoint.TaskStateSnapshot;
+import org.apache.flink.runtime.clusterframework.types.AllocationID;
+import org.apache.flink.runtime.jobgraph.JobVertexID;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.annotation.Nonnegative;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.Executor;
+
+/**
+ * Main implementation of a {@link TaskLocalStateStore}.
+ */
+public class TaskLocalStateStoreImpl implements TaskLocalStateStore {
+
+ /** Logger for this class. */
+ private static final Logger LOG =
LoggerFactory.getLogger(TaskLocalStateStoreImpl.class);
+
+ /** Maximum number of retained snapshots. */
+ @VisibleForTesting
+ static final int MAX_RETAINED_SNAPSHOTS = 5;
+
--- End diff --
- What is `MAX_RETAINED_SNAPSHOTS` used for? I found all the checkpoints
that satisfied `checkpointId < confirmedCheckpointId ` will be removed in
`confirmCheckpoint()`.
- Is it's value can be configured?
---
