[ 
https://issues.apache.org/jira/browse/FLINK-6364?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15993343#comment-15993343
 ] 

ASF GitHub Bot commented on FLINK-6364:
---------------------------------------

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

    https://github.com/apache/flink/pull/3801#discussion_r114368960
  
    --- Diff: 
flink-contrib/flink-statebackend-rocksdb/src/main/java/org/apache/flink/contrib/streaming/state/RocksDBKeyedStateBackend.java
 ---
    @@ -137,6 +156,14 @@
        /** Number of bytes required to prefix the key groups. */
        private final int keyGroupPrefixBytes;
     
    +   /** The sst files materialized in pending checkpoints */
    +   private final SortedMap<Long, Map<String, StreamStateHandle>> 
materializedSstFiles = new TreeMap<>();
    +
    +   /** The identifier of the last completed checkpoint */
    +   private final long lastCompletedCheckpointId = -1;
    --- End diff --
    
    Currently, this value `lastCompletedCheckpointId` is not maintained at all, 
and also the `materializedSstFiles` is ever-growing. I think the whole feedback 
from the checkpoint coordinator about completed checkpoints is still missing. 
Are you planning to do this in another PR?


> Implement incremental checkpointing in RocksDBStateBackend
> ----------------------------------------------------------
>
>                 Key: FLINK-6364
>                 URL: https://issues.apache.org/jira/browse/FLINK-6364
>             Project: Flink
>          Issue Type: Sub-task
>          Components: State Backends, Checkpointing
>            Reporter: Xiaogang Shi
>            Assignee: Xiaogang Shi
>
> {{RocksDBStateBackend}} is well suited for incremental checkpointing because 
> RocksDB is base on LSM trees,  which record updates in new sst files and all 
> sst files are immutable. By only materializing those new sst files, we can 
> significantly improve the performance of checkpointing.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Reply via email to