SampleContainerLogAggregationPolicy is inconsistent with expectations

repro steps:

Configure the following parameters in yarn-site.xml

  <property>
    <name>yarn.nodemanager.log-aggregation.policy.class</name>
 <value>org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.SampleContainerLogAggregationPolicy</value>
  </property>
  <property>
    <name>yarn.nodemanager.log-aggregation.policy.parameters</name>
    <value>SR:0.3,MIN:20</value>
  </property>

run pi:

hadoop  org.apache.hadoop.examples.QuasiMonteCarlo 100 5

three nodemanagers in my cluster

Expected quantity：20+(100-20)*0.3+1=45 container logs uploaded

Actual quantity: 21 container logs uploaded

So why are there fewer logs uploaded?

I print debug log in SampleContainerLogAggregationPolicy.

shouldDoLogAggregation()

logContext.getContainerId().hashCode():-1455756646

logContext.getContainerId().hashCode() % (1/sampleRate):-0.041277885

So in most cases, it will not be uploaded