Matt Cuento created FLINK-38345:
-----------------------------------
Summary: HybridSource checkpoint recovery results in NPE if
addSource depends on previousEnumerator from SourceSwitchContext
Key: FLINK-38345
URL: https://issues.apache.org/jira/browse/FLINK-38345
Project: Flink
Issue Type: Bug
Components: Connectors / HybridSource
Affects Versions: 1.19.1, 2.0.0
Reporter: Matt Cuento
`org.apache.flink.connector.base.source.hybrid.HybridSource` upon recovery from
a checkpoint calls `restoreEnumerator()` with the configured source factories
and checkpoint information.
The enumerator
`org.apache.flink.connector.base.source.hybrid.HybridSourceSplitEnumerator`
then is started which invokes `switchEnumerator`.
The `currentEnumerator` is null on recovery and as part of source switching
logic, `previousEnumerator` becomes null.
For hybrid source implementations that require the use of the
`org.apache.flink.connector.base.source.hybrid.HybridSource.SourceSwitchContext`
to derive a start position at switch time, we end up in a situation where
`getPreviousEnumerator()` returns null, meaning we're unable to derive a start
position on checkpoint recovery.
Enumerator state is later deserialized and recovered, but requires a source to
get the serializer needed. So long as a source depends on a prior enumerator to
derive the start position, this bug will be in effect.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
