Hi, Alex
What state backend do you choose?
If you choose MemoryStateBackend or FsStateBackend, `transient` keyword may
not have effect because MemoryStateBackend does not serialize state for
regular read/write accesses but keeps it as objects on the heap.
If you choose RocksDBStateBackend, I thought it was expected behavior
because RocksDBStateBackend stores all state as byte arrays in embedded
RocksDB instances. Therefore, it de/serializes the state of a key for every
read/write access. CurrentFile is null because the transient variable
would not be serialized by default.
Best,
JING ZHANG
Alex Drobinsky <alex.drobin...@gmail.com> 于2021年10月11日周一 下午4:33写道：
> Dear flink community,
>
> I have following state class ( irrelevant fields removed )
> public class MultiStorePacketState implements Serializable {
>
> public transient RandomAccessFile currentFile = null;
> public long timerValue;
> public String fileName;
> public String exportedFileName;
> public String sessionKey;
> public long fileOffset = 0;
>
> }
>
> Once in a while, currentFile became *nullified, *this happens after I
> extract state via
>
> MultiStorePacketState so = state.value();
>
> The frequency of this behaviour is similar to checkpoint interval (
> checkpoint interval defined as 5 seconds and first occurence of this problem
> is also 5 seconds), otherwise I don't have any clues to a possible
> explanation.
>
> Is it an expected side effect of checkpoint procedure ?
>
> Best regards,
> Alex
>
>
