rfc: Resolved-ts for Large Transactions #114
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| *TBD: should it also update max_ts?* | ||
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| #### TiKV txn_status_cache |
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Does it mean that it requires all information about these large txns must exist in the cache? If so, I'm afraid it's no longer a cache as literal.
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The cache operates on a "best effort" basis rather than being mandatory. In the case of cache miss, the system falls back to use start_ts.
…me discussions Signed-off-by: ekexium <[email protected]>
| #### 3.2.1 Coordinator | ||
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| **Proposed Change:** | ||
| - TTL manager fetches latest TSO as min_commit_ts candidate. |
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Is the TTL manager the worker in tidb which updates the TTL of primary key for each transaction?
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Yes, because we want to piggyback the min_commit_ts in the heartbeat message.
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| ## 5. Cost Analysis | ||
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| - Memory: ~33 bytes per cache entry. TiKV instances can hold millions of entries. |
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IS it 33 bytes for each transaction? Why 33 bytes total?
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Yes. The minimum memory requirement for each cache entry is 33:
8 (start_ts) + 8 (min_commit_ts) + 1 (status) + 8 (TTL) = 33 bytes.
I've clarified this in the doc.
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| - The TTL manager goroutine fetches latest TSO as min_commit_ts candidate. | ||
| - Updates committer's inner state and PK in TiKV. | ||
| - PK update piggybacked on `heartbeat` request. | ||
| - Broadcasts `start_ts` and new `min_commit_ts` to all TiKV stores. |
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Will there be kvproto changes like adding new KV interfaces?
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Better to describe it in the document.
Signed-off-by: ekexium <[email protected]>
Signed-off-by: ekexium <[email protected]>
Signed-off-by: ekexium <[email protected]>
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