[improve] [broker] Follower do not need to retrieve load data in zk.#20970
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thetumbled wants to merge 4 commits into
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[improve] [broker] Follower do not need to retrieve load data in zk.#20970thetumbled wants to merge 4 commits into
thetumbled wants to merge 4 commits into
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Contributor
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I support the idea, in large cluster deployment follower read zk is very heavy. We need more unit test on failover or other logic if we remove the retrieve logic. |
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Author
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PTAL, thanks. @codelipenghui @heesung-sn @Demogorgon314 |
Contributor
Can we confirm that followers never use any of this info in their logic(any regressions caused by this change)? |
| // Executor is shutting down | ||
| if (isLeader()) { | ||
| try { | ||
| scheduler.submit(ModularLoadManagerImpl.this::updateAll); |
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We need a unit test to verify this change.
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The pr had no activity for 30 days, mark with Stale label. |
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Motivation
Load balance module in pulsar broker pose greate pressure on zk.
Currently,
ModularLoadManagerImplis the mainLoadManagerin 2.x version, which work as a centralized way. Most of the time, leader broker take the responsibility of shedding and assignning, while followers update their load data to zk for leader. Leader broker retrieve load data of all brokers in the cluster to make decision.But, i found that not only leader will retrieve all load data (include LocalBrokerData and BundleData), but also followers, which is unnecessary and pose greate pressure to zk.
Modifications
Disable load data retrieve for followers.
Result as follows, only the zk instance that serve for leader broker present high throught.
The peak total read traffic of the zk cluster has decreased from 24kb/s to 10kb/s.
Verifying this change
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Documentation
docdoc-requireddoc-not-neededdoc-completeMatching PR in forked repository
PR in forked repository: thetumbled#23