[BEAM-11784] Java pipeline proto serialization does not ensure topological ordering of root transforms

• Type: Bug
• Status: Resolved
• Priority: P1
• Resolution: Fixed
• Fix Version/s: 2.29.0
• Component/s: sdk-java-core
• Labels: stale-assigned
• Assignee: Kenneth Knowles
• Reporter: Kenneth Knowles
• Created: 09/Feb/21 21:34
• Updated: 12/Mar/21 23:48
• Resolved: 12/Mar/21 23:48

Description

Seen these root orders when running ImpulseTest.testImpulse:

• ["Impulse", "PAssert$0", "FlatMapElements"]
• ["FlatMapElements", "PAssert$0", "Impulse"]

Pipeline is:

PCollection<Integer> result =
        p.apply(Impulse.create())
            .apply(
                FlatMapElements.into(TypeDescriptors.integers())
                    .via(impulse -> Arrays.asList(1, 2, 3)));
    PAssert.that(result).containsInAnyOrder(1, 2, 3);

The topological order is linear and is neither of the above.

Issue Links

• links to: GitHub Pull Request #13942