[FLINK-27681] Improve the availability of Flink when the RocksDB file is corrupted.

• Type: Improvement
• Status: Open
• Priority: Critical
• Resolution: Unresolved
• Component/s: Runtime / State Backends
• Labels: pull-request-available
• Assignee: Yue Ma
• Reporter: Ming Li
• Created: 18/May/22 09:06
• Updated: 14/Dec/23 17:27

Description

We have encountered several times when the RocksDB checksum does not match or the block verification fails when the job is restored. The reason for this situation is generally that there are some problems with the machine where the task is located, which causes the files uploaded to HDFS to be incorrect, but it has been a long time (a dozen minutes to half an hour) when we found this problem. I'm not sure if anyone else has had a similar problem.

Since this file is referenced by incremental checkpoints for a long time, when the maximum number of checkpoints reserved is exceeded, we can only use this file until it is no longer referenced. When the job failed, it cannot be recovered.

Therefore we consider:
1. Can RocksDB periodically check whether all files are correct and find the problem in time?
2. Can Flink automatically roll back to the previous checkpoint when there is a problem with the checkpoint data, because even with manual intervention, it just tries to recover from the existing checkpoint or discard the entire state.
3. Can we increase the maximum number of references to a file based on the maximum number of checkpoints reserved? When the number of references exceeds the maximum number of checkpoints -1, the Task side is required to upload a new file for this reference. Not sure if this way will ensure that the new file we upload will be correct.

Issue Links

• links to: GitHub Pull Request #23765