[FLINK-9034] State Descriptors drop TypeInformation on serialization

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.4.2, 1.5.0
• Fix Version/s: 1.5.0
• Component/s: Runtime / State Backends
• Assignee: Stephan Ewen
• Reporter: Stephan Ewen
• Created: 20/Mar/18 20:15
• Updated: 02/Apr/18 14:22
• Resolved: 22/Mar/18 15:24

Description

The following code currently causes problems

public class MyFunction extends RichMapFunction<A, B>  {

    private final ValueStateDescriptor<MyType> descr = new ValueStateDescriptor<>("state name", MyType.class);

    private ValueState<MyType> state;

    @Override
    public void open() {
        state = getRuntimeContext().getValueState(descr);
    }
}

The problem is that the state descriptor drops the type information and creates a serializer before serialization as part of shipping the function in the cluster. To do that, it initializes the serializer with an empty execution config, making serialization inconsistent.

This is mainly an artifact from the days when dropping the type information before shipping was necessary, because the type info was not serializable. It now is, and we can fix that bug.

Issue Links

• links to: GitHub Pull Request #5732