...

• Throw ArgumentParserException if the value is outside the [0.0, 1.0] range;
• Throw ArgumentParserException if transactionAbortRatio is greater than 0.0 but transactions are not enabled, since aborting without transactions is meaningless.

3. Abort logic

There are currently two places where commitTransaction() is called:

• In-loop: when the transaction duration exceeds transactionDurationMs
• Post-loop: to handle remaining uncommitted records

At both commit points, use the existing SplittableRandom instance to randomly decide whether to commit or abort based on the ratio:

if (random.nextDouble() < config.transactionAbortRatio) {
    producer.abortTransaction();
} else {
    producer.commitTransaction();
}

Note: The current code uses a fixed seed (new SplittableRandom(0)). The abort decision reuses the same instance, so for a given ratio and record count, results are deterministic and reproducible.

4. Warmup phase behavior

Transactions during the warmup phase are also subject to the --transaction-abort-ratio. The warmup phase (introduced in KAFKA-17645) is designed to bring the system into a steady state before collecting performance statistics. If the abort ratio were only applied during the steady-state phase, the system would transition from an all-commit warmup to a mixed commit/abort steady state, introducing an additional settling period that undermines the purpose of warmup. Applying the same abort ratio during warmup ensures the system has already stabilized under the target conditions when steady-state measurement begins.

Compatibility, Deprecation, and Migration Plan

...

• When --transaction-abort-ratio is not specified, the tool behaves exactly as before;
• No existing configuration options are changed or removed;
• All existing functionality remains intact.

Test Plan

Unit tests will cover the following scenarios:

1. Argument parsing: Verify that --transaction-abort-ratio 0.5 is parsed correctly
2. Range validation: Verify that values outside [0.0, 1.0] (e.g., -0.1, 1.5) throw an error
3. Transaction dependency validation: Verify that setting a non-zero abort ratio without enabling transactions throws an error
4. Abort logic:
   • With ratio 0.0, all transactions are committed (commitTransaction() is called)
   • With ratio 1.0, all transactions are aborted (abortTransaction() is called)
   • With intermediate ratios, verify that the number of commit and abort calls matches the expected proportion

Rejected Alternatives

None