Dumpling will stuck while it's expect to fallback to LOCK TABLES when FTWRL blocking for a long time · pingcap/tidb#56838

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good first issuetype/enhancement

説明

Enhancement

in https://github.com/pingcap/tidb/pull/36576 I want to implement a fallback strategy. But in line 1420 dumpling does not use the context with timeout https://github.com/pingcap/tidb/blob/7ce5bd752f668b4037a25ded97752f3eca258100/dumpling/export/dump.go#L1409-L1422

So current behaviour is, when upstream reports error like unsupported statement for FLUSH TABLE WITH READ LOCK, dumplling will fallback to LOCK TABLES. When upstream supports it but due to active sessions or other reason FTWRL is blocking, dumpling will stuck.

Maybe in the latter case it's also acceptable to fallback?

コントリビューターガイド

技術スタック: gosql
領域: backenddatabase
Issue 種別: feature
難度: 3
推定時間: half day
活動状況: fresh
明確さ: clear
前提条件: Go basicscontext/timeout usageTiDB/Dumpling internals
初心者向け度: 40
調査方針: Look at the referenced PR #36576 to understand the existing fallback logic. In dumpling/export/dump.go, around line 1420, the code does not use a context with timeout. You need to modify that section to use a context with a timeout so that if FTWRL blocks, it can fallback to LOCK TABLES. Check if there are any existing tests for this behavior and ensure new changes are covered.