[Bug] Debezium integration tests can hang CI for 45 minutes instead of failing

[david-streamlio]

Description

DebeziumMysqlSourceTest and DebeziumPostgresSourceTest (both on master) can hang indefinitely rather than fail if their connector delivers fewer CDC records than expected. When that happens the GitHub Actions job runs until its timeout-minutes: 45 and reports a cancellation, not a test failure — no useful diagnostics, 45 minutes of runner time consumed.

This is not hypothetical. It was observed in CI on #58: the Tests - Connectors job ran for exactly 45m15s and was cancelled. The mechanism was reproduced locally.

Root cause

AbstractKafkaConnectSource.read() is a while (true) loop whose only return yields a record; an empty poll hits continue. It never returns null.

The tests do:

Awaitility.await()
    .atMost(60, TimeUnit.SECONDS)
    .untilAsserted(() -> {
        int recordCount = 0;
        Record<KeyValue<byte[], byte[]>> record;
        while ((record = source.read()) != null) {   // never null
            ...
            if (recordCount >= 2) break;             // only escape
        }
        assertTrue(recordCount >= 2, ...);
    });

If fewer than 2 records ever arrive, read() spins forever. Awaitility's atMost(60s) cannot save it: untilAsserted does not interrupt a blocked assertion, so the deadline never fires.

Neither test declares a timeOut, so TestNG does not bound them either. They pass today only because MySQL and Postgres reliably emit their snapshot records — the moment either under-delivers for any environmental reason, CI hangs.

Reproduction

Raising the expected record count above the number of seeded rows produces the hang on the unmodified harness. With the fix applied (see below), the same condition fails in ~37 seconds with a TimeoutException naming the connector.

Fix

Read each record on a bounded worker thread (per-record deadline, cancel(true) on timeout, shutdownNow() in cleanup) and add a test-level timeOut as a backstop, so under-delivery fails promptly with a diagnosable message. This pattern is already applied in #58.

Scope

• debezium/mysql — DebeziumMysqlSourceTest (no timeOut)
• debezium/postgres — DebeziumPostgresSourceTest (no timeOut)

Also affected, tracked in their own PRs:

• debezium/mongodb — fixed in [improve][test] Add Debezium MongoDB source integration test #58
• debezium/mssql — [improve][test] Add Debezium SQL Server source integration test #60 has the same pattern and no timeOut
• debezium/oracle — [improve][test] Add Debezium Oracle source integration test #62 has a timeOut backstop but still reads on the test thread
• debezium/mariadb — [feat][io] Add Debezium MariaDB source connector #69 has a timeOut backstop but still reads on the test thread