Hi,
when working with state you have to create a state descriptor ([1]).
This will have a TypeInformation or TypeSerializer that Flink uses to
(de)serialize your state. This will be used to serialize your state to
bytes, in the case of RocksDB we serialize both the key (the key of the
record that is used to key the stream) and the value (your state object,
MyState in you example) to bytes and store them in the RocksDB key-value
store.
Best,
Aljoscha
[1]
https://ci.apache.org/projects/flink/flink-docs-master/dev/stream/state/state.html
On 09.03.20 12:27, kant kodali wrote:
Hi All,
I want to do stateful streaming and I was wondering how Custom objects get
mapped into rocksdb?
say I have the following class that represents my state
public class MyState {
private HashMap<String, T> map1 ; // T can be any type
private HashMap<Integer, S> map2; // S can be any type
}
I wonder how these two maps gets mapped into rocksdb? and how does Flink
know that map1 and map2 together are part of my state but not
individual ones in isolation?
Thanks!
