Hi, fsync mode on WAL is not supported currenlty. So theoritically it is possible that in case of power failure the data is lost because DataNodes didn't flush it to physical disk.
I know that probability is small and data center should have additional power source, but still it is possible. How do you deal with it? Do you care about it? How to check after the disaster later from which moment the data is lost? How often DataNodes flush buffers to disk? What is your solution? Regards
