The meaning of pending-peer-region-count when stopping a tikv-server node

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This topic has been translated from a Chinese forum by GPT and might contain errors.

Original topic: 停掉tikv-server节点，pending-peer-region-count代表的含义

| username: HACK

[TiDB Usage Environment] Online, Testing, Research
[TiDB Version]
[Encountered Problem]

Manually stopped an instance of a tikv-server node in the cluster. The current total number of regions in the cluster is 431.
In the PD monitoring interface, check the region health panel, where: down-peer-region-count=431, pending-peer-region-count=283.

Question:
What does pending-peer-region-count represent, and why is pending-peer-region-count=283 in my test scenario?
[Reproduction Path] What operations were performed to encounter the problem
[Problem Phenomenon and Impact]

[Attachment]

Please provide the version information of each component, such as cdc/tikv, which can be obtained by executing cdc version/tikv-server --version.

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| username: h5n1 | Original post link

The explanations for the above Region information panel are as follows:

  • miss-peer-region-count: The number of Regions with missing replicas, which will not always be greater than 0.
  • extra-peer-region-count: The number of Regions with extra replicas, which can occur during scheduling.
  • empty-region-count: The number of empty Regions, generally caused by TRUNCATE TABLE / DROP TABLE statements. If the number is large, consider enabling cross-table Region merge.
  • pending-peer-region-count: The number of Regions with Raft logs lagging behind. It is normal to have a small number of pending peers due to scheduling, but if the number of pending peers remains high (for more than 30 minutes), there may be an issue.
  • down-peer-region-count: The number of Regions reported by the Raft leader as having unresponsive peers.
  • offline-peer-region-count: The number of Regions in the process of peer offline.
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| username: HACK | Original post link

I’ve seen this. If that’s the case, then pending-peer-region-count should also be equal to 431, I think.

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| username: h5n1 | Original post link

Two concepts, right?

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| username: xfworld | Original post link

Is there only one TiKV node in the cluster environment? If there is only one, then it is equivalent.

If there are multiple, it is normal, and some region leaders will become invalid.

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| username: HACK | Original post link

Oh, I understand now, thank you! I forgot about the leader, haha.

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| username: system | Original post link

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