Will the consistency read of dumpling affect GC?

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

Original topic: dumpling的一致性读会影响GC吗？

| username: jarry_618

For example, when dumpling exports a full database of 100G, it defaults to snapshot consistency read, assuming it takes a long time. At this time, dumpling maintains consistency based on MVCC, but by default, tidbserver performs GC every 10 minutes. Now, two situations may occur:

  1. During GC, the corresponding historical versions are not deleted first and are only removed after dumpling finishes. This will cause the space of tikv to increase and affect efficiency.
  2. GC is not affected, and dumpling will fail later, reporting an error similar to “snapshot too old.”

Could you please explain what the real situation is?

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| username: tidb狂热爱好者 | Original post link

Yes. It will only perform garbage collection after the dump is complete.

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| username: 啦啦啦啦啦 | Original post link

It is related to the version. Versions 4.0 or above will automatically configure an extended GC time and will not affect the original cluster.

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| username: system | Original post link

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