apache / pulsar

Apache Pulsar - distributed pub-sub messaging system
https://pulsar.apache.org/
Apache License 2.0
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[Bug] Brokers can't reach balanced state sometimes when using UnifromLoadShedder #21174

Open aloyszhang opened 1 year ago

aloyszhang commented 1 year ago

Search before asking

Version

2.10.5

Minimal reproduce step

  1. Start 3 brokers and create some topics
  2. Start producing and consuming for all these topics
  3. Enable load balance with Uniformloadshedder:
    • loadBalancerMsgThroughputMultiplierDifferenceShedderThreshold=1.1
    • loadBalancerMsgRateDifferenceShedderThreshold=0, means disable msgRate based shedding
  4. Use the default loadBalancerLoadPlacementStrategy org.apache.pulsar.broker.loadbalance.impl.LeastLongTermMessageRate
  5. Restart brokers several times to trigger the load balance
  6. There is a chance to see brokers can't reach the balanced state for long time.

What did you expect to see?

All brokers should reach a balanced state after rounds of shedding.

What did you see instead?

Brokers may stay in an un-balanced state for a long time.

Anything else?

No response

Are you willing to submit a PR?

github-actions[bot] commented 11 months ago

The issue had no activity for 30 days, mark with Stale label.