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https://issues.apache.org/jira/browse/FLINK-8360?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16372594#comment-16372594
 ] 

ASF GitHub Bot commented on FLINK-8360:
---------------------------------------

Github user StefanRRichter commented on a diff in the pull request:

    https://github.com/apache/flink/pull/5239#discussion_r169897306
  
    --- Diff: 
flink-runtime/src/main/java/org/apache/flink/runtime/state/DirectoryStateHandle.java
 ---
    @@ -0,0 +1,101 @@
    +/*
    + * 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.core.fs.FileSystem;
    +import org.apache.flink.core.fs.Path;
    +
    +import javax.annotation.Nonnull;
    +
    +import java.io.IOException;
    +
    +/**
    + * This state handle represents a directory. This class is, for example, 
used to represent the directory of RocksDB's
    + * native checkpoint directories for local recovery.
    + */
    +public class DirectoryStateHandle implements StateObject {
    +
    +   /** Serial version. */
    +   private static final long serialVersionUID = 1L;
    +
    +   /** The path that describes the directory. */
    +   @Nonnull
    +   private final Path directory;
    +
    +   /** The filesystem that contains the directory described by path. */
    +   @Nonnull
    +   private final FileSystem fileSystem;
    --- End diff --
    
    It is true, and just was no problem because this handle is never 
serialized, it just is forced to inherit this from `StateObject`. 👍 


> Implement task-local state recovery
> -----------------------------------
>
>                 Key: FLINK-8360
>                 URL: https://issues.apache.org/jira/browse/FLINK-8360
>             Project: Flink
>          Issue Type: New Feature
>          Components: State Backends, Checkpointing
>            Reporter: Stefan Richter
>            Assignee: Stefan Richter
>            Priority: Major
>             Fix For: 1.5.0
>
>
> This issue tracks the development of recovery from task-local state. The main 
> idea is to have a secondary, local copy of the checkpointed state, while 
> there is still a primary copy in DFS that we report to the checkpoint 
> coordinator.
> Recovery can attempt to restore from the secondary local copy, if available, 
> to save network bandwidth. This requires that the assignment from tasks to 
> slots is as sticky is possible.
> For starters, we will implement this feature for all managed keyed states and 
> can easily enhance it to all other state types (e.g. operator state) later.



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