Tan Kim created FLINK-31977:
-------------------------------
Summary: If scaling.effectiveness.detection.enabled is false, the
call to the detectIneffectiveScaleUp() function is unnecessary
Key: FLINK-31977
URL: https://issues.apache.org/jira/browse/FLINK-31977
Project: Flink
Issue Type: Improvement
Components: Autoscaler
Affects Versions: 1.17.0
Reporter: Tan Kim
The code below is a function to detect inefficient scaleups.
It returns a result if the value of SCALING_EFFECTIVENESS_DETECTION_ENABLED
(scaling.effectiveness.detection.enabled) is true after all the necessary
computations for detection, but this is an unnecessary computation.
{code:java}
JobVertexScaler.java #175
private boolean detectIneffectiveScaleUp(
AbstractFlinkResource<?, ?> resource,
JobVertexID vertex,
Configuration conf,
Map<ScalingMetric, EvaluatedScalingMetric> evaluatedMetrics,
ScalingSummary lastSummary) {
double lastProcRate =
lastSummary.getMetrics().get(TRUE_PROCESSING_RATE).getAverage(); //
22569.315633422066
double lastExpectedProcRate =
lastSummary.getMetrics().get(EXPECTED_PROCESSING_RATE).getCurrent(); // 37340.0
var currentProcRate =
evaluatedMetrics.get(TRUE_PROCESSING_RATE).getAverage();
// To judge the effectiveness of the scale up operation we compute how much
of the expected
// increase actually happened. For example if we expect a 100 increase in
proc rate and only
// got an increase of 10 we only accomplished 10% of the desired increase.
If this number is
// below the threshold, we mark the scaling ineffective.
double expectedIncrease = lastExpectedProcRate - lastProcRate;
double actualIncrease = currentProcRate - lastProcRate;
boolean withinEffectiveThreshold =
(actualIncrease / expectedIncrease)
>=
conf.get(AutoScalerOptions.SCALING_EFFECTIVENESS_THRESHOLD);
if (withinEffectiveThreshold) {
return false;
}
var message = String.format(INNEFFECTIVE_MESSAGE_FORMAT, vertex);
eventRecorder.triggerEvent(
resource,
EventRecorder.Type.Normal,
EventRecorder.Reason.IneffectiveScaling,
EventRecorder.Component.Operator,
message);
if (conf.get(AutoScalerOptions.SCALING_EFFECTIVENESS_DETECTION_ENABLED)) {
LOG.info(message);
return true;
} else {
return false;
}
} {code}
It's better to check SCALING_EFFECTIVENESS_DETECTION_ENABLED beforehand and
then call the function, as shown in the if statement in the code below, which
is the caller of this function.
{code:java}
JobVertexScaler.java #150
if (currentParallelism == lastSummary.getNewParallelism() &&
lastSummary.isScaledUp()) {
if (scaledUp) {
if(conf.get(AutoScalerOptions.SCALING_EFFECTIVENESS_DETECTION_ENABLED))
{
detectIneffectiveScaleUp(resource, vertex, conf, evaluatedMetrics,
lastSummary);
} else {
return true;
}
} else {
return detectImmediateScaleDownAfterScaleUp(vertex, conf,
lastScalingTs);
}
}{code}
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
