From 162066e2d11b0ae8c2feca9c66f0b05f9a36afd0 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Wed, 18 Mar 2026 18:04:33 +0800 Subject: [PATCH 01/26] Add temp.md --- temp.md | 1 + 1 file changed, 1 insertion(+) create mode 100644 temp.md diff --git a/temp.md b/temp.md new file mode 100644 index 0000000000000..af27ff4986a7b --- /dev/null +++ b/temp.md @@ -0,0 +1 @@ +This is a test file. \ No newline at end of file From b3318c00089edd758f5b431346eba705e0291faa Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Wed, 18 Mar 2026 18:04:39 +0800 Subject: [PATCH 02/26] Delete temp.md --- temp.md | 1 - 1 file changed, 1 deletion(-) delete mode 100644 temp.md diff --git a/temp.md b/temp.md deleted file mode 100644 index af27ff4986a7b..0000000000000 --- a/temp.md +++ /dev/null @@ -1 +0,0 @@ -This is a test file. \ No newline at end of file From fbd1b14b4c8a2175c76a9f1c6e030381f76270b0 Mon Sep 17 00:00:00 2001 From: "github-actions[bot]" Date: Wed, 18 Mar 2026 10:05:51 +0000 Subject: [PATCH 03/26] Auto-sync: Update English docs from Chinese PR Synced from: https://github.com/pingcap/docs-cn/pull/21445 Target PR: https://github.com/pingcap/docs/pull/22578 AI Provider: gemini Co-authored-by: github-actions[bot] --- releases/release-8.5.6.md | 147 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100644 releases/release-8.5.6.md diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md new file mode 100644 index 0000000000000..920a16aaa26be --- /dev/null +++ b/releases/release-8.5.6.md @@ -0,0 +1,147 @@ +--- +title: TiDB 8.5.6 Release Notes +summary: Understand the compatibility changes, improvements, and bug fixes in the TiDB 8.5.6 release. +--- + +# TiDB 8.5.6 Release Notes + +Release Date: 2026-xx-xx + +TiDB Version: 8.5.6 + +Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with-tidb) | [Production Deployment](https://docs.pingcap.com/zh/tidb/v8.5/production-deployment-using-tiup) | [Download Offline Package](https://pingkai.cn/download#tidb-community) + +## Feature Details + +### Stability + +- The ability to set resource limits for background tasks in Resource Control is now Generally Available (GA) [#56019](https://github.com/pingcap/tidb/issues/56019) @[glorv](https://github.com/glorv) + + TiDB Resource Control can identify and lower the priority of background tasks. In some scenarios, even with idle resources, users may want to keep the consumption of background tasks at a very low level. Starting from v8.4.0, you can use the `UTILIZATION_LIMIT` parameter to set the maximum percentage of resources that background tasks under Resource Control can use, controlling the usage of all background tasks on each node below this percentage. This feature allows you to finely control the resource consumption of background tasks, further enhancing cluster stability. + + In v8.5.6, this feature is Generally Available (GA). + + For more information, please refer to the [User Documentation](/tidb-resource-control-background-tasks.md). + +### Data Migration + +- (dup): release-9.0.0.md > # Data Migration * Migrated sync-diff-inspector from the `pingcap/tidb-tools` repository to the `pingcap/tiflow` repository [#11672](https://github.com/pingcap/tiflow/issues/11672) @[joechenrh](https://github.com/joechenrh) + +## Compatibility Changes + +- note [#issue](https://github.com/pingcap/${repo-name}/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + +## Improvements + ++ TiDB + + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + ++ TiKV + + - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - (dup): release-8.5.4.md > Improvements > TiKV - Optimized the calculation of the default value for the gRPC thread pool size. The previous fixed value has been adjusted to a dynamic calculation based on the total CPU configuration, preventing performance bottlenecks caused by an insufficient number of gRPC threads [#18613](https://github.com/tikv/tikv/issues/18613) @[LykxSassinator](https://github.com/LykxSassinator) + - (dup): release-8.5.5.md > Improvements > TiKV - Limited the rate of BR log recovery requests when TiKV memory usage is high, preventing TiKV OOM [#18124](https://github.com/tikv/tikv/issues/18124) @[3pointer](https://github.com/3pointer) + ++ PD + + - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - (dup): release-8.5.5.md > Improvements > PD - Optimized high-cardinality metrics, reducing PD's memory consumption and pressure on the monitoring system [#9357](https://github.com/tikv/pd/issues/9357) @[rleungx](https://github.com/rleungx) + - (dup): release-7.5.7.md > Improvements > PD - Reduced unnecessary error logs [#9370](https://github.com/tikv/pd/issues/9370) @[bufferflies](https://github.com/bufferflies) + ++ TiFlash + + - note [#issue](https://github.com/pingcap/tiflash/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tiflash/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + ++ Tools + + + Backup & Restore (BR) + + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + + + TiCDC + + - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + + + TiDB Data Migration (DM) + + - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + + + TiDB Lightning + + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + + + Dumpling + + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + + + TiUP + + - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + +## Bug Fixes + ++ TiDB + + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + ++ TiKV + + - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - (dup): release-5.1.4.md > Bug Fixes > TiKV - Fixed the risk of data inconsistency in rare cases during prewrite request retries in pessimistic transactions [#11187](https://github.com/tikv/tikv/issues/11187) + ++ PD + + - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - (dup): release-8.5.4.md > Bug Fixes > PD - Fixed an issue where Resource Manager incorrectly allocated tokens, causing queries to hang [#9455](https://github.com/tikv/pd/issues/9455) @[JmPotato](https://github.com/JmPotato) + ++ TiFlash + + - note [#issue](https://github.com/pingcap/tiflash/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tiflash/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + ++ Tools + + + Backup & Restore (BR) + + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - (dup): release-8.5.5.md > Bug Fixes > Tools > Backup & Restore (BR) - Fixed an issue where enabling log backup in a cluster with a large number of Regions led to excessive memory consumption [#18719](https://github.com/tikv/tikv/issues/18719) @[YuJuncen](https://github.com/YuJuncen) + + + TiCDC + + - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + + + TiDB Data Migration (DM) + + - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + + + TiDB Lightning + + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + + + Dumpling + + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + + + TiUP + + - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) \ No newline at end of file From bcbf29b043ddc95238acd31f0c60492176a4bc79 Mon Sep 17 00:00:00 2001 From: houfaxin Date: Thu, 19 Mar 2026 10:13:50 +0800 Subject: [PATCH 04/26] Update release-8.5.6.md --- releases/release-8.5.6.md | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 920a16aaa26be..ec6c2c05dc7af 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -25,7 +25,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with ### Data Migration -- (dup): release-9.0.0.md > # Data Migration * Migrated sync-diff-inspector from the `pingcap/tidb-tools` repository to the `pingcap/tiflow` repository [#11672](https://github.com/pingcap/tiflow/issues/11672) @[joechenrh](https://github.com/joechenrh) +- (dup): release-9.0.0.md > # 数据迁移 * 将 sync-diff-inspector 从 `pingcap/tidb-tools` 迁移至 `pingcap/tiflow` 代码仓库 [#11672](https://github.com/pingcap/tiflow/issues/11672) @[joechenrh](https://github.com/joechenrh) ## Compatibility Changes @@ -42,15 +42,15 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.4.md > Improvements > TiKV - Optimized the calculation of the default value for the gRPC thread pool size. The previous fixed value has been adjusted to a dynamic calculation based on the total CPU configuration, preventing performance bottlenecks caused by an insufficient number of gRPC threads [#18613](https://github.com/tikv/tikv/issues/18613) @[LykxSassinator](https://github.com/LykxSassinator) - - (dup): release-8.5.5.md > Improvements > TiKV - Limited the rate of BR log recovery requests when TiKV memory usage is high, preventing TiKV OOM [#18124](https://github.com/tikv/tikv/issues/18124) @[3pointer](https://github.com/3pointer) + - (dup): release-8.5.4.md > 改进提升> TiKV - 优化 gRPC 线程池线程数量默认值的计算方式，将原固定值调整为根据总的 CPU 配置动态计算，避免因 gRPC 线程数量过小导致的性能瓶颈 [#18613](https://github.com/tikv/tikv/issues/18613) @[LykxSassinator](https://github.com/LykxSassinator) + - (dup): release-8.5.5.md > 改进提升> TiKV - 在 TiKV 内存占用高时，对 BR 的日志恢复请求进行限流，防止 TiKV OOM [#18124](https://github.com/tikv/tikv/issues/18124) @[3pointer](https://github.com/3pointer) + PD - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.5.md > Improvements > PD - Optimized high-cardinality metrics, reducing PD's memory consumption and pressure on the monitoring system [#9357](https://github.com/tikv/pd/issues/9357) @[rleungx](https://github.com/rleungx) - - (dup): release-7.5.7.md > Improvements > PD - Reduced unnecessary error logs [#9370](https://github.com/tikv/pd/issues/9370) @[bufferflies](https://github.com/bufferflies) + - (dup): release-8.5.5.md > 改进提升> PD - 优化了高基数指标，降低 PD 的内存占用和监控系统压力 [#9357](https://github.com/tikv/pd/issues/9357) @[rleungx](https://github.com/rleungx) + - (dup): release-7.5.7.md > 改进提升> PD - 减少非必要的错误日志 [#9370](https://github.com/tikv/pd/issues/9370) @[bufferflies](https://github.com/bufferflies) + TiFlash @@ -100,13 +100,13 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-5.1.4.md > Bug Fixes > TiKV - Fixed the risk of data inconsistency in rare cases during prewrite request retries in pessimistic transactions [#11187](https://github.com/tikv/tikv/issues/11187) + - (dup): release-5.1.4.md > Bug 修复> TiKV - 修复悲观事务中 prewrite 请求重试在极少数情况下影响数据一致性的风险 [#11187](https://github.com/tikv/tikv/issues/11187) + PD - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.4.md > Bug Fixes > PD - Fixed an issue where Resource Manager incorrectly allocated tokens, causing queries to hang [#9455](https://github.com/tikv/pd/issues/9455) @[JmPotato](https://github.com/JmPotato) + - (dup): release-8.5.4.md > 错误修复> PD - 修复 Resource Manager 错误分配 token 导致查询卡住的问题 [#9455](https://github.com/tikv/pd/issues/9455) @[JmPotato](https://github.com/JmPotato) + TiFlash @@ -119,7 +119,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.5.md > Bug Fixes > Tools > Backup & Restore (BR) - Fixed an issue where enabling log backup in a cluster with a large number of Regions led to excessive memory consumption [#18719](https://github.com/tikv/tikv/issues/18719) @[YuJuncen](https://github.com/YuJuncen) + - (dup): release-8.5.5.md > 错误修复> Tools> Backup & Restore (BR) - 修复集群中存在大量 Region 时，开启日志备份导致内存占用过高的问题 [#18719](https://github.com/tikv/tikv/issues/18719) @[YuJuncen](https://github.com/YuJuncen) + TiCDC From 6d7792388e4d49e0fb2f57040bede07b39a97204 Mon Sep 17 00:00:00 2001 From: houfaxin Date: Thu, 19 Mar 2026 10:29:02 +0800 Subject: [PATCH 05/26] Update release-8.5.6.md --- releases/release-8.5.6.md | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index ec6c2c05dc7af..387ce8278fbd6 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -25,7 +25,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with ### Data Migration -- (dup): release-9.0.0.md > # 数据迁移 * 将 sync-diff-inspector 从 `pingcap/tidb-tools` 迁移至 `pingcap/tiflow` 代码仓库 [#11672](https://github.com/pingcap/tiflow/issues/11672) @[joechenrh](https://github.com/joechenrh) +- (dup): release-9.0.0.md > # Data migration * Migrate sync-diff-inspector from `pingcap/tidb-tools` to `pingcap/tiflow` repository [#11672](https://github.com/pingcap/tiflow/issues/11672) @[joechenrh](https://github.com/joechenrh) ## Compatibility Changes @@ -42,15 +42,15 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.4.md > 改进提升> TiKV - 优化 gRPC 线程池线程数量默认值的计算方式，将原固定值调整为根据总的 CPU 配置动态计算，避免因 gRPC 线程数量过小导致的性能瓶颈 [#18613](https://github.com/tikv/tikv/issues/18613) @[LykxSassinator](https://github.com/LykxSassinator) - - (dup): release-8.5.5.md > 改进提升> TiKV - 在 TiKV 内存占用高时，对 BR 的日志恢复请求进行限流，防止 TiKV OOM [#18124](https://github.com/tikv/tikv/issues/18124) @[3pointer](https://github.com/3pointer) + - (dup): release-8.5.4.md > Improvements> TiKV - Optimize the calculation method of the default gRPC thread pool size by making it dynamically calculated based on total CPU quota instead of a fixed value, avoiding performance bottlenecks caused by insufficient gRPC threads [#18613](https://github.com/tikv/tikv/issues/18613) @[LykxSassinator](https://github.com/LykxSassinator) + - (dup): release-8.5.5.md > Improvements> TiKV - Throttle BR log restore requests when TiKV memory usage is high to prevent TiKV OOM [#18124](https://github.com/tikv/tikv/issues/18124) @[3pointer](https://github.com/3pointer) + PD - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.5.md > 改进提升> PD - 优化了高基数指标，降低 PD 的内存占用和监控系统压力 [#9357](https://github.com/tikv/pd/issues/9357) @[rleungx](https://github.com/rleungx) - - (dup): release-7.5.7.md > 改进提升> PD - 减少非必要的错误日志 [#9370](https://github.com/tikv/pd/issues/9370) @[bufferflies](https://github.com/bufferflies) + - (dup): release-8.5.5.md > Improvements> PD - Optimize metrics with high cardinality to reduce PD memory usage and relieve pressure on the monitoring system [#9357](https://github.com/tikv/pd/issues/9357) @[rleungx](https://github.com/rleungx) + - (dup): release-7.5.7.md > Improvements> PD - Reduce unnecessary error logs [#9370](https://github.com/tikv/pd/issues/9370) @[bufferflies](https://github.com/bufferflies) + TiFlash @@ -100,13 +100,13 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-5.1.4.md > Bug 修复> TiKV - 修复悲观事务中 prewrite 请求重试在极少数情况下影响数据一致性的风险 [#11187](https://github.com/tikv/tikv/issues/11187) + - (dup): release-5.1.4.md > Bug fixes> TiKV - Fix the rare data inconsistency issue when retrying a prewrite request in pessimistic transactions [#11187](https://github.com/tikv/tikv/issues/11187) + PD - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.4.md > 错误修复> PD - 修复 Resource Manager 错误分配 token 导致查询卡住的问题 [#9455](https://github.com/tikv/pd/issues/9455) @[JmPotato](https://github.com/JmPotato) + - (dup): release-8.5.4.md > Bug fixes> PD - Fix the issue that the Resource Manager incorrectly allocates tokens, causing queries to be stuck [#9455](https://github.com/tikv/pd/issues/9455) @[JmPotato](https://github.com/JmPotato) + TiFlash @@ -119,7 +119,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.5.md > 错误修复> Tools> Backup & Restore (BR) - 修复集群中存在大量 Region 时，开启日志备份导致内存占用过高的问题 [#18719](https://github.com/tikv/tikv/issues/18719) @[YuJuncen](https://github.com/YuJuncen) + - (dup): release-8.5.5.md > Bug fixes> Tools> Backup & Restore (BR) - Fix the issue that enabling log backup causes excessive memory usage when the cluster contains many Regions [#18719](https://github.com/tikv/tikv/issues/18719) @[YuJuncen](https://github.com/YuJuncen) + TiCDC From b042351d3cf771d3e8c8374553c0a4ef6f585673 Mon Sep 17 00:00:00 2001 From: houfaxin Date: Thu, 19 Mar 2026 10:56:34 +0800 Subject: [PATCH 06/26] Update release-8.5.6.md --- releases/release-8.5.6.md | 5 ----- 1 file changed, 5 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 387ce8278fbd6..154cda5ad65f9 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -42,14 +42,11 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.4.md > Improvements> TiKV - Optimize the calculation method of the default gRPC thread pool size by making it dynamically calculated based on total CPU quota instead of a fixed value, avoiding performance bottlenecks caused by insufficient gRPC threads [#18613](https://github.com/tikv/tikv/issues/18613) @[LykxSassinator](https://github.com/LykxSassinator) - - (dup): release-8.5.5.md > Improvements> TiKV - Throttle BR log restore requests when TiKV memory usage is high to prevent TiKV OOM [#18124](https://github.com/tikv/tikv/issues/18124) @[3pointer](https://github.com/3pointer) + PD - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.5.md > Improvements> PD - Optimize metrics with high cardinality to reduce PD memory usage and relieve pressure on the monitoring system [#9357](https://github.com/tikv/pd/issues/9357) @[rleungx](https://github.com/rleungx) - (dup): release-7.5.7.md > Improvements> PD - Reduce unnecessary error logs [#9370](https://github.com/tikv/pd/issues/9370) @[bufferflies](https://github.com/bufferflies) + TiFlash @@ -106,7 +103,6 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.4.md > Bug fixes> PD - Fix the issue that the Resource Manager incorrectly allocates tokens, causing queries to be stuck [#9455](https://github.com/tikv/pd/issues/9455) @[JmPotato](https://github.com/JmPotato) + TiFlash @@ -119,7 +115,6 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - (dup): release-8.5.5.md > Bug fixes> Tools> Backup & Restore (BR) - Fix the issue that enabling log backup causes excessive memory usage when the cluster contains many Regions [#18719](https://github.com/tikv/tikv/issues/18719) @[YuJuncen](https://github.com/YuJuncen) + TiCDC From 4a973fc8cd581354614f9304acd78414caa26226 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Thu, 19 Mar 2026 11:31:59 +0800 Subject: [PATCH 07/26] Update releases/release-8.5.6.md --- releases/release-8.5.6.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 154cda5ad65f9..70aa62dd0ba6c 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -15,7 +15,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with ### Stability -- The ability to set resource limits for background tasks in Resource Control is now Generally Available (GA) [#56019](https://github.com/pingcap/tidb/issues/56019) @[glorv](https://github.com/glorv) +- The ability to set resource limits for background tasks in Resource Control is now Generally Available (GA) [#56019](https://github.com/pingcap/tidb/issues/56019) @[glorv](https://github.com/glorv) **tw@hfxsd** TiDB Resource Control can identify and lower the priority of background tasks. In some scenarios, even with idle resources, users may want to keep the consumption of background tasks at a very low level. Starting from v8.4.0, you can use the `UTILIZATION_LIMIT` parameter to set the maximum percentage of resources that background tasks under Resource Control can use, controlling the usage of all background tasks on each node below this percentage. This feature allows you to finely control the resource consumption of background tasks, further enhancing cluster stability. From 068e5ebe1f6b870fb25d207de3564f5a88730744 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Thu, 19 Mar 2026 15:07:35 +0800 Subject: [PATCH 08/26] Update releases/release-8.5.6.md --- releases/release-8.5.6.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 70aa62dd0ba6c..add527a6a0f66 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -9,7 +9,7 @@ Release Date: 2026-xx-xx TiDB Version: 8.5.6 -Try it out: [Quick Start](https://docs.pingcap.com/zh/tidb/v8.5/quick-start-with-tidb) | [Production Deployment](https://docs.pingcap.com/zh/tidb/v8.5/production-deployment-using-tiup) | [Download Offline Package](https://pingkai.cn/download#tidb-community) +Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-tidb) | [Production Deployment](https://docs.pingcap.com/tidb/v8.5/production-deployment-using-tiup) | [Download Offline Package](https://pingkai.cn/download#tidb-community) ## Feature Details From 02224aafa0ee534963c0761203f1e090c99d4b81 Mon Sep 17 00:00:00 2001 From: dongmen <20351731+asddongmen@users.noreply.github.com> Date: Wed, 25 Mar 2026 16:42:33 +0800 Subject: [PATCH 09/26] Update release notes for TiCDC fixes and enhancements --- releases/release-8.5.6.md | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index add527a6a0f66..a728680aaeab5 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -118,8 +118,10 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti + TiCDC - - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - Fixed an issue where changefeed might repeatedly create invalid dispatchers when the server restarts. [#4452](https://github.com/pingcap/ticdc/issues/4452) @[wlwilliamx](https://github.com/wlwilliamx) + - Fixed an issue where table renaming operations could not be performed normally when the upstream TiDB version was <= v8.1.x. [#4392](https://github.com/pingcap/ticdc/issues/4392) @[lidezhu](https://github.com/lidezhu) + - Fixed a bug during data scanning to avoid potential abnormal crashes of TiKV when CDC is enabled. [#19404](https://github.com/tikv/tikv/issues/19404) @[wk989898](https://github.com/wk989898) + - Supported Azure Managed Identity authentication for azblob sinks and fixed a potential stuck issue during cloud storage uploads. [#3093](https://github.com/pingcap/ticdc/issues/3093) @[wlwilliamx](https://github.com/wlwilliamx) + TiDB Data Migration (DM) @@ -139,4 +141,4 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti + TiUP - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) \ No newline at end of file + - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) From cd9a122a8fdacf213c381163250ee8775d2e0db7 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Wed, 25 Mar 2026 18:48:25 +0800 Subject: [PATCH 10/26] Apply suggestions from code review Co-authored-by: HuaiyuXu Co-authored-by: Bisheng Huang --- releases/release-8.5.6.md | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index a728680aaeab5..d55b3c9d4f4f5 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -35,13 +35,16 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti + TiDB - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - Enhanced slow query log control by supporting [`tidb_slow_log_rules`](/system-variables.md#tidb_slow_log_rules-new-in-v900) for targeted slow query log output based on combinations of multiple metrics, [`tidb_slow_log_max_per_sec`](/system-variables.md#tidb_slow_log_max_per_sec-new-in-v900) for limiting the number of slow query log entries per second, and the [`WRITE_SLOW_LOG`](/identify-slow-queries.md#related-hint) hint for forcing specified SQL statements to be recorded in the slow query log [#64010](https://github.com/pingcap/tidb/issues/64010) @[zimulala](https://github.com/zimulala) + - Enhanced [Top SQL](/dashboard/top-sql.md) for resource analysis by supporting Top `5`, `20`, or `100` queries, hotspot analysis sorted by CPU, network traffic, or logical I/O, and aggregated analysis by `Query`, `Table`, `DB`, or `Region` on TiKV instances [#62916](https://github.com/pingcap/tidb/issues/62916) @[yibin87](https://github.com/yibin87) - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + TiKV - - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - Add MVCC-read-aware load-based compaction to prioritize regions with heavy MVCC read overhead. [#19133](https://github.com/tikv/tikv/issues/19133) @[mittalrishabh](https://github.com/mittalrishabh) + - Optimize stale-range cleanup during scaling by deleting stale keys directly instead of ingesting SST files, reducing latency impact. [#18042](https://github.com/tikv/tikv/issues/18042) @[LykxSassinator](https://github.com/LykxSassinator) + - Make default gRPC raft connection and concurrency settings scale with CPU quota to improve resource utilization. [#18613](https://github.com/tikv/tikv/issues/18613) @[LykxSassinator](https://github.com/LykxSassinator) + - Add Top SQL support for collecting network traffic and logical I/O information to help diagnose SQL performance issues. [#18815](https://github.com/tikv/tikv/issues/18815) @[yibin87](https://github.com/yibin87) + PD @@ -95,8 +98,12 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti + TiKV - - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/tikv/tikv/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - Fix the issue that global indexes on non-unique columns of partitioned tables might become inconsistent and return incorrect results in some cases. [#19262](https://github.com/tikv/tikv/issues/19262) @[mjonss](https://github.com/mjonss) + - Fix the issue that stalled coprocessor snapshot retrieval could occupy unified read pool workers until request deadlines expired, delaying other read requests. [#18491](https://github.com/tikv/tikv/issues/18491) @[AndreMouche](https://github.com/AndreMouche) + - Fix the issue that follower replica reads could remain blocked on disk-full TiKV nodes by rejecting read-index requests on disk-full followers. [#19201](https://github.com/tikv/tikv/issues/19201) @[glorv](https://github.com/glorv) + - Fix the issue that resolved-ts task backlogs could cause OOM when the resolved-ts worker is busy. [#18359](https://github.com/tikv/tikv/issues/18359) @[overvenus](https://github.com/overvenus) + - Fix long-tail follower-read latency during leader transfer by retrying read-index requests sooner and adding a dedicated retry interval setting. [#18417](https://github.com/tikv/tikv/issues/18417) @[gengliqi](https://github.com/gengliqi) + - Fix ingest latency spikes in large clusters by increasing the default `rocksdb.max-manifest-file-size` from 128 MiB to 256 MiB. [#18996](https://github.com/tikv/tikv/issues/18996) @[glorv](https://github.com/glorv) - (dup): release-5.1.4.md > Bug fixes> TiKV - Fix the rare data inconsistency issue when retrying a prewrite request in pessimistic transactions [#11187](https://github.com/tikv/tikv/issues/11187) + PD From 107708f06345f28d9b029ede3db417805c59e9cd Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Thu, 26 Mar 2026 10:48:55 +0800 Subject: [PATCH 11/26] Apply suggestions from code review Co-authored-by: bb7133 --- releases/release-8.5.6.md | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index d55b3c9d4f4f5..3d5f4109824e6 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -37,7 +37,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti - Enhanced slow query log control by supporting [`tidb_slow_log_rules`](/system-variables.md#tidb_slow_log_rules-new-in-v900) for targeted slow query log output based on combinations of multiple metrics, [`tidb_slow_log_max_per_sec`](/system-variables.md#tidb_slow_log_max_per_sec-new-in-v900) for limiting the number of slow query log entries per second, and the [`WRITE_SLOW_LOG`](/identify-slow-queries.md#related-hint) hint for forcing specified SQL statements to be recorded in the slow query log [#64010](https://github.com/pingcap/tidb/issues/64010) @[zimulala](https://github.com/zimulala) - Enhanced [Top SQL](/dashboard/top-sql.md) for resource analysis by supporting Top `5`, `20`, or `100` queries, hotspot analysis sorted by CPU, network traffic, or logical I/O, and aggregated analysis by `Query`, `Table`, `DB`, or `Region` on TiKV instances [#62916](https://github.com/pingcap/tidb/issues/62916) @[yibin87](https://github.com/yibin87) - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - 新增 DXF 的 max_node_count 配置项支持 [#66376](https://github.com/pingcap/tidb/pull/66376)@[D3Hunter](https://github.com/D3Hunter) + TiKV @@ -93,8 +93,18 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti + TiDB - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - Fix the issue that upgrading from release-8.5-20250606-v8.5.2 to upstream release-8.5 can skip PITR metadata upgrades and cause PITR operations to fail. [#66994](https://github.com/pingcap/tidb/issues/66994) @[fzzf678](https://github.com/fzzf678) + - Fix the issue that after EXCHANGE PARTITION, non-unique or nullable unique global indexes on non-clustered partitioned tables can become inconsistent and return incomplete results. [#65289](https://github.com/pingcap/tidb/issues/65289) @[mjonss](https://github.com/mjonss) + - Support column-level privileges in GRANT and REVOKE. [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) + - Improve the performance of privilege updates such as GRANT and REVOKE in deployments with large numbers of privilege entries. [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) + - Fix the issue that KILL QUERY incorrectly kills idle connections. [#65447](https://github.com/pingcap/tidb/issues/65447) @[gengliqi](https://github.com/gengliqi) + - Fix the issue that column-level privilege checks can be incorrect for JOIN ... USING, NATURAL JOIN, and INSERT ... ON DUPLICATE KEY UPDATE. [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) + - Improve privilege-check performance for deployments with many column-level privilege entries. [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) + - Add cluster_id to mysql.tidb so external tools can determine whether two TiDB instances belong to the same cluster. [#59476](https://github.com/pingcap/tidb/issues/59476) @[YangKeao](https://github.com/YangKeao) + - Improve the slow query log by printing non-printable prepared-statement arguments as hexadecimal literals. [#65383](https://github.com/pingcap/tidb/issues/65383) @[dveeden](https://github.com/dveeden) + - 修复 tidb_service_scope 设置时未统一转换为小写的问题 [#66835](https://github.com/pingcap/tidb/pull/66835)@[D3Hunter](https://github.com/D3Hunter) + - 修复 TiDB 重启后无法展示亲和力表的问题 [#66284](https://github.com/pingcap/tidb/issues/66284) @[lcwangchao](https://github.com/lcwangchao) + - 修复可能出现的内存泄漏 [#65522](https://github.com/pingcap/tidb/issues/65522) @[bufferflies](https://github.com/bufferflies) + TiKV From 5e1fd675d07526905e9c7e68863456770e7b9f6d Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Thu, 26 Mar 2026 11:34:14 +0800 Subject: [PATCH 12/26] Update releases/release-8.5.6.md --- releases/release-8.5.6.md | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 3d5f4109824e6..e9f25a7c9e613 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -123,8 +123,9 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti + TiFlash - - note [#issue](https://github.com/pingcap/tiflash/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tiflash/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - 修复当一个列执行将列属性 `NOT NULL` 转为 `NULL` 的 DDL 之后，TiFlash 与 TiKV 之间可能产生不一致数据的问题 [#10680](https://github.com/pingcap/tiflash/issues/10680) @[JaySon-Huang](https://github.com/JaySon-Huang) + - 修复 Grafana 面板中 Raft throughput 可能会错误地显示一个非常大的数值的问题 [#10701](https://github.com/pingcap/tiflash/issues/10701) @[CalvinNeo](https://github.com/CalvinNeo) + - 修复 runtime filter 开启情况下，如果 join key 数据类型不一致时，join 结果可能出错的问题 [#10699](https://github.com/pingcap/tiflash/issues/10699) @[ChangRui-Ryan](https://github.com/ChangRui-Ryan) + Tools From b8f5f3b43e636b6d20d618294ec88cac8686b08e Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Thu, 26 Mar 2026 14:56:26 +0800 Subject: [PATCH 13/26] Apply suggestions from code review --- releases/release-8.5.6.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index e9f25a7c9e613..0548487d9f85a 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -38,6 +38,8 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti - Enhanced slow query log control by supporting [`tidb_slow_log_rules`](/system-variables.md#tidb_slow_log_rules-new-in-v900) for targeted slow query log output based on combinations of multiple metrics, [`tidb_slow_log_max_per_sec`](/system-variables.md#tidb_slow_log_max_per_sec-new-in-v900) for limiting the number of slow query log entries per second, and the [`WRITE_SLOW_LOG`](/identify-slow-queries.md#related-hint) hint for forcing specified SQL statements to be recorded in the slow query log [#64010](https://github.com/pingcap/tidb/issues/64010) @[zimulala](https://github.com/zimulala) - Enhanced [Top SQL](/dashboard/top-sql.md) for resource analysis by supporting Top `5`, `20`, or `100` queries, hotspot analysis sorted by CPU, network traffic, or logical I/O, and aggregated analysis by `Query`, `Table`, `DB`, or `Region` on TiKV instances [#62916](https://github.com/pingcap/tidb/issues/62916) @[yibin87](https://github.com/yibin87) - 新增 DXF 的 max_node_count 配置项支持 [#66376](https://github.com/pingcap/tidb/pull/66376)@[D3Hunter](https://github.com/D3Hunter) + - 调整部分 stats 相关日志为 warning 级别 [#58315](https://github.com/pingcap/tidb/pull/58315)@[hawkingrei](https://github.com/hawkingrei) + - 调整 tidb_analyze_column_options 默认值为 all [#64992](https://github.com/pingcap/tidb/issues/64992) @[0xPoe](https://github.com/0xPoe) + TiKV @@ -105,6 +107,8 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti - 修复 tidb_service_scope 设置时未统一转换为小写的问题 [#66835](https://github.com/pingcap/tidb/pull/66835)@[D3Hunter](https://github.com/D3Hunter) - 修复 TiDB 重启后无法展示亲和力表的问题 [#66284](https://github.com/pingcap/tidb/issues/66284) @[lcwangchao](https://github.com/lcwangchao) - 修复可能出现的内存泄漏 [#65522](https://github.com/pingcap/tidb/issues/65522) @[bufferflies](https://github.com/bufferflies) + - 修复系统表可能影响 stats healthy 监控的问题 [#64080](https://github.com/pingcap/tidb/issues/64080) @[ti-chi-bot](https://github.com/ti-chi-bot) + - 修复 stats delta 数据可能刷新不及时的问题 [#65426](https://github.com/pingcap/tidb/issues/65426) @[ti-chi-bot](https://github.com/ti-chi-bot) + TiKV From 0b6eb7cc63fa7b244a631002865352f17ffca9d7 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Thu, 26 Mar 2026 15:06:43 +0800 Subject: [PATCH 14/26] Update releases/release-8.5.6.md --- releases/release-8.5.6.md | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 0548487d9f85a..dea3e757a5e48 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -23,6 +23,28 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti For more information, please refer to the [User Documentation](/tidb-resource-control-background-tasks.md). +### 可观测性 + +- 支持多维度、多粒度定义慢查询日志的触发规则（GA）[#62959](https://github.com/pingcap/tidb/issues/62959) @[zimulala](https://github.com/zimulala) **tw@lilin90** + + 当前 TiDB 定位慢查询语句的主要方法是设置系统变量 tidb_slow_log_threshold，该机制触发慢日志控制粒度粗（整个实例级别全局控制，不支持会话和SQL级别精细化控制）、触发条件仅执行时间（Query_time）一种，无法满足复杂场景慢日志抓取以精细化定位问题的需求。 + + 本功能通过设置 tidb_slow_log_rules 系统变量，支持用户在实例、会话、SQL级别定义多维度（如 Query_time、Digest、Mem_max、KV_total 等等）的慢查询日志抓取规则，实现更灵活的精细化控制。 + + 在 v8.5.6 中，该功能成为正式功能（GA）。 + + 更多信息，请参考 [用户文档](/identify-slow-queries.md)。 + +- TOP SQL 增加网络流量和逻辑IO 数据（GA）[#62916](https://github.com/pingcap/tidb/issues/62916) @[yibin87](https://github.com/yibin87) **tw@qiancai** + + 当前 TiDB TOP SQL 中仅包含 CPU 的相关指标数据，在遇到复杂情况时不利于排查问题。 + + 本功能在 Top SQL 设置中增加开启 **TiKV 网络I0 采集（多维度）**，方便用户进一步查看指定 TiKV 实例的 Network Bytes、Logical IO Bytes 等指标，并按 By Query、By Table、By DB 或 By Region 维度进行聚合分析。 + + 在 v8.5.6 中，该功能成为正式功能（GA）。 + + 更多信息，请参考 [用户文档](/dashboard/top-sql.md)。 + ### Data Migration - (dup): release-9.0.0.md > # Data migration * Migrate sync-diff-inspector from `pingcap/tidb-tools` to `pingcap/tiflow` repository [#11672](https://github.com/pingcap/tiflow/issues/11672) @[joechenrh](https://github.com/joechenrh) From 91d51fabe0edf36c55730771814c04524cc3eabd Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Thu, 26 Mar 2026 15:42:00 +0800 Subject: [PATCH 15/26] Update releases/release-8.5.6.md --- releases/release-8.5.6.md | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index dea3e757a5e48..477956eaf4830 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -157,8 +157,10 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti + Backup & Restore (BR) - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - 修复了 log backup 的 flush_ts 可能为 0 的问题 [#19406](https://github.com/tikv/tikv/issues/19406) @[YuJuncen](https://github.com/YuJuncen) + - 修复 BR 在使用 GCP S3 API server 进行 multipart upload 时因缺少 `Content-Length` 头而失败的问题 [#19352](https://github.com/tikv/tikv/issues/19352) @[Leavrth](https://github.com/Leavrth) + - 修复 BR `restore point` 可能长时间卡在 `waiting for schema info finishes reloading` 并在 15 分钟后超时失败的问题 [#66110](https://github.com/pingcap/tidb/issues/66110) @[kennytm](https://github.com/kennytm) + - 修复 BR 在恢复带有 `SHARD_ROW_ID_BITS`、`PRE_SPLIT_REGIONS` 和 `merge_option` 属性的表时无法正确预分裂 Region 的问题 [#65060](https://github.com/pingcap/tidb/issues/65060) @[JoyC-dev](https://github.com/JoyC-dev) + TiCDC From 51a41b8e5effee6ec5693be810b3260d1ff50128 Mon Sep 17 00:00:00 2001 From: Aolin Date: Fri, 27 Mar 2026 11:38:09 +0800 Subject: [PATCH 16/26] add DM and Dumpling --- releases/release-8.5.6.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 477956eaf4830..d677fd7ee098a 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -97,6 +97,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - Support migrating data from MySQL 8.4 as a data source. The compatibility level for MySQL 8.4 is upgraded from "Incompatible" to "Experimental" [#11020](https://github.com/pingcap/tiflow/issues/11020) @[dveeden](https://github.com/dveeden) + TiDB Lightning @@ -107,6 +108,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - Support exporting data from MySQL 8.4 by adopting the updated MySQL binary log terminology [#53082](https://github.com/pingcap/tidb/issues/53082) @[dveeden](https://github.com/dveeden) + TiUP From 2b935d2b0cc5c718d4abd45b5315266db9c197d0 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Mon, 30 Mar 2026 09:48:26 +0800 Subject: [PATCH 17/26] Update releases/release-8.5.6.md --- releases/release-8.5.6.md | 1 + 1 file changed, 1 insertion(+) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index d677fd7ee098a..a665726ded22c 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -133,6 +133,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti - 修复可能出现的内存泄漏 [#65522](https://github.com/pingcap/tidb/issues/65522) @[bufferflies](https://github.com/bufferflies) - 修复系统表可能影响 stats healthy 监控的问题 [#64080](https://github.com/pingcap/tidb/issues/64080) @[ti-chi-bot](https://github.com/ti-chi-bot) - 修复 stats delta 数据可能刷新不及时的问题 [#65426](https://github.com/pingcap/tidb/issues/65426) @[ti-chi-bot](https://github.com/ti-chi-bot) + - 修复事务中第一条语句使用 fair locking 模式上锁时，有时可能使事务 keep alive 失效、并被意外回滚的问题 [#66571](https://github.com/pingcap/tidb/issues/66571) @[MyonKeminta](https://github.com/MyonKeminta) + TiKV From 44306afd3a473101756359299c69e9f6942c3593 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Mon, 30 Mar 2026 10:02:51 +0800 Subject: [PATCH 18/26] Apply suggestions from code review Co-authored-by: Frank945946 <108602632+Frank945946@users.noreply.github.com> Co-authored-by: Ziqian Qin --- releases/release-8.5.6.md | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index a665726ded22c..8e3dce11fe4f9 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -12,7 +12,32 @@ TiDB Version: 8.5.6 Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-tidb) | [Production Deployment](https://docs.pingcap.com/tidb/v8.5/production-deployment-using-tiup) | [Download Offline Package](https://pingkai.cn/download#tidb-community) ## Feature Details +- +### **SQL** +- Support column-level privilege management [#61706](https://github.com/pingcap/tidb/issues/61706) [@CbcWestwolf](https://github.com/CbcWestwolf),[@fzzf678](https://github.com/fzzf678) **tw@hfxsd** +Before v8.5.6, TiDB privilege control mainly covered the database, and table levels, and did not support granting or revoking privileges on specific columns as MySQL does. As a result, when you needed to restrict users to accessing only a subset of sensitive columns in a table, TiDB could not provide sufficiently fine-grained access control. + +Starting from v8.5.6, TiDB supports column-level privilege management. You can use the `GRANT` and `REVOKE` statements to grant or revoke privileges on specific columns, and TiDB performs privilege checks based on column privileges during query processing and execution plan construction. This enables more fine-grained access control and better supports sensitive data isolation and the principle of least privilege. + + For more information, see the user documentation. + + - Support table aliases referenced in the `FOR UPDATE OF` clause [#65532](https://github.com/pingcap/tidb/pull/65532) [@cryo-zd](https://github.com/cryo-zd)**tw@lilin90** + +Before v8.5.6, when a `SELECT ... FOR UPDATE OF ` statement referenced a table alias in the locking clause, TiDB could fail to resolve the alias correctly and return a `table not exists` error even though the alias was valid. + +Starting from v8.5.6, TiDB supports table aliases in the `FOR UPDATE OF` clause. TiDB can now correctly resolve the locking target from the `FROM` clause, including aliased tables, so that row locks are applied as expected. This improves MySQL compatibility and makes `SELECT ... FOR UPDATE OF` statements more reliable in queries that use table aliases. + + For more information, see the user documentation. + +### **DB operations** +- Support specifying the maximum number of nodes for distributed execution tasks [#58937](https://github.com/pingcap/tidb/pull/58937) [@tangenta](https://github.com/tangenta), [@D3Hunter](https://github.com/D3Hunter) + +Before v8.5.6, TiDB did not support efficiently limiting how many nodes a distributed execution task could use. When you wanted to control resource usage for distributed task execution, TiDB did not provide a dedicated option to constrain the maximum node count. + +Starting from v8.5.6, TiDB supports the `tidb_max_dist_task_nodes` system variable, which lets you specify the maximum number of TiDB nodes used by a distributed execution task. This gives you more flexibility to manage resource usage and tune distributed task execution based on workload and cluster conditions. + + For more information, see the user documentation. ### Stability - The ability to set resource limits for background tasks in Resource Control is now Generally Available (GA) [#56019](https://github.com/pingcap/tidb/issues/56019) @[glorv](https://github.com/glorv) **tw@hfxsd** @@ -56,7 +81,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti ## Improvements + TiDB - +- Improve plan selection for queries with IN predicates on index prefix columns. TiDB can now leverage merge sort to preserve order in ORDER BY ... LIMIT queries, reducing unnecessary scans and improving performance.[#62694](https://github.com/pingcap/tidb/pull/62694) [@time-and-fate](https://github.com/time-and-fate)**tw@hfxsd** - Enhanced slow query log control by supporting [`tidb_slow_log_rules`](/system-variables.md#tidb_slow_log_rules-new-in-v900) for targeted slow query log output based on combinations of multiple metrics, [`tidb_slow_log_max_per_sec`](/system-variables.md#tidb_slow_log_max_per_sec-new-in-v900) for limiting the number of slow query log entries per second, and the [`WRITE_SLOW_LOG`](/identify-slow-queries.md#related-hint) hint for forcing specified SQL statements to be recorded in the slow query log [#64010](https://github.com/pingcap/tidb/issues/64010) @[zimulala](https://github.com/zimulala) - Enhanced [Top SQL](/dashboard/top-sql.md) for resource analysis by supporting Top `5`, `20`, or `100` queries, hotspot analysis sorted by CPU, network traffic, or logical I/O, and aggregated analysis by `Query`, `Table`, `DB`, or `Region` on TiKV instances [#62916](https://github.com/pingcap/tidb/issues/62916) @[yibin87](https://github.com/yibin87) - 新增 DXF 的 max_node_count 配置项支持 [#66376](https://github.com/pingcap/tidb/pull/66376)@[D3Hunter](https://github.com/D3Hunter) @@ -137,6 +162,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti + TiKV + - Fix a memory leak in crossbeam skiplist. [#19285](https://github.com/tikv/tikv/issues/19285) @[ekexium](https://github.com/ekexium) - Fix the issue that global indexes on non-unique columns of partitioned tables might become inconsistent and return incorrect results in some cases. [#19262](https://github.com/tikv/tikv/issues/19262) @[mjonss](https://github.com/mjonss) - Fix the issue that stalled coprocessor snapshot retrieval could occupy unified read pool workers until request deadlines expired, delaying other read requests. [#18491](https://github.com/tikv/tikv/issues/18491) @[AndreMouche](https://github.com/AndreMouche) - Fix the issue that follower replica reads could remain blocked on disk-full TiKV nodes by rejecting read-index requests on disk-full followers. [#19201](https://github.com/tikv/tikv/issues/19201) @[glorv](https://github.com/glorv) From 65f4ade93f986d7cbad42fc6392678e5005898f8 Mon Sep 17 00:00:00 2001 From: houfaxin Date: Mon, 30 Mar 2026 10:31:54 +0800 Subject: [PATCH 19/26] make it ready for tw to edit --- releases/release-8.5.6.md | 125 ++++++++++++++++++++------------------ 1 file changed, 66 insertions(+), 59 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 8e3dce11fe4f9..5e2de56546eb4 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -12,32 +12,17 @@ TiDB Version: 8.5.6 Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-tidb) | [Production Deployment](https://docs.pingcap.com/tidb/v8.5/production-deployment-using-tiup) | [Download Offline Package](https://pingkai.cn/download#tidb-community) ## Feature Details -- -### **SQL** -- Support column-level privilege management [#61706](https://github.com/pingcap/tidb/issues/61706) [@CbcWestwolf](https://github.com/CbcWestwolf),[@fzzf678](https://github.com/fzzf678) **tw@hfxsd** - -Before v8.5.6, TiDB privilege control mainly covered the database, and table levels, and did not support granting or revoking privileges on specific columns as MySQL does. As a result, when you needed to restrict users to accessing only a subset of sensitive columns in a table, TiDB could not provide sufficiently fine-grained access control. -Starting from v8.5.6, TiDB supports column-level privilege management. You can use the `GRANT` and `REVOKE` statements to grant or revoke privileges on specific columns, and TiDB performs privilege checks based on column privileges during query processing and execution plan construction. This enables more fine-grained access control and better supports sensitive data isolation and the principle of least privilege. +### 性能 - For more information, see the user documentation. - - - Support table aliases referenced in the `FOR UPDATE OF` clause [#65532](https://github.com/pingcap/tidb/pull/65532) [@cryo-zd](https://github.com/cryo-zd)**tw@lilin90** +- 外键检查支持共享锁（GA） [#66154](https://github.com/pingcap/tidb/issues/66154) @[you06](https://github.com/glorv) **tw@qiancai** -Before v8.5.6, when a `SELECT ... FOR UPDATE OF
` statement referenced a table alias in the locking clause, TiDB could fail to resolve the alias correctly and return a `table not exists` error even though the alias was valid. + 对子表进行写入时，支持用户通过设置参数 tidb_foreign_key_check_in_shared_lock 来指定在父表加共享锁实现外键约束检查，相比以前仅支持排它锁，现方案可降低锁冲突提升子表并发写入性能。 -Starting from v8.5.6, TiDB supports table aliases in the `FOR UPDATE OF` clause. TiDB can now correctly resolve the locking target from the `FROM` clause, including aliased tables, so that row locks are applied as expected. This improves MySQL compatibility and makes `SELECT ... FOR UPDATE OF` statements more reliable in queries that use table aliases. + 在V8.5.6 中，该功能成为正式功能 (GA)。 - For more information, see the user documentation. - -### **DB operations** -- Support specifying the maximum number of nodes for distributed execution tasks [#58937](https://github.com/pingcap/tidb/pull/58937) [@tangenta](https://github.com/tangenta), [@D3Hunter](https://github.com/D3Hunter) + 更多信息，请参考[用户文档](/foreign-key.md)。 -Before v8.5.6, TiDB did not support efficiently limiting how many nodes a distributed execution task could use. When you wanted to control resource usage for distributed task execution, TiDB did not provide a dedicated option to constrain the maximum node count. - -Starting from v8.5.6, TiDB supports the `tidb_max_dist_task_nodes` system variable, which lets you specify the maximum number of TiDB nodes used by a distributed execution task. This gives you more flexibility to manage resource usage and tune distributed task execution based on workload and cluster conditions. - - For more information, see the user documentation. ### Stability - The ability to set resource limits for background tasks in Resource Control is now Generally Available (GA) [#56019](https://github.com/pingcap/tidb/issues/56019) @[glorv](https://github.com/glorv) **tw@hfxsd** @@ -69,19 +54,68 @@ Starting from v8.5.6, TiDB supports the `tidb_max_dist_task_nodes` system variab 在 v8.5.6 中，该功能成为正式功能（GA）。 更多信息，请参考 [用户文档](/dashboard/top-sql.md)。 - + +### **SQL** + +- Support column-level privilege management [#61706](https://github.com/pingcap/tidb/issues/61706) [@CbcWestwolf](https://github.com/CbcWestwolf),[@fzzf678](https://github.com/fzzf678) **tw@hfxsd** + + Before v8.5.6, TiDB privilege control mainly covered the database, and table levels, and did not support granting or revoking privileges on specific columns as MySQL does. As a result, when you needed to restrict users to accessing only a subset of sensitive columns in a table, TiDB could not provide sufficiently fine-grained access control. + + Starting from v8.5.6, TiDB supports column-level privilege management. You can use the `GRANT` and `REVOKE` statements to grant or revoke privileges on specific columns, and TiDB performs privilege checks based on column privileges during query processing and execution plan construction. This enables more fine-grained access control and better supports sensitive data isolation and the principle of least privilege. + + For more information, see the [user documentation](/column-privilege-management.md). + + - Support table aliases referenced in the `FOR UPDATE OF` clause [#65532](https://github.com/pingcap/tidb/pull/65532) [@cryo-zd](https://github.com/cryo-zd) **tw@lilin90** + + Before v8.5.6, when a `SELECT ... FOR UPDATE OF
` statement referenced a table alias in the locking clause, TiDB could fail to resolve the alias correctly and return a `table not exists` error even though the alias was valid. + + Starting from v8.5.6, TiDB supports table aliases in the `FOR UPDATE OF` clause. TiDB can now correctly resolve the locking target from the `FROM` clause, including aliased tables, so that row locks are applied as expected. This improves MySQL compatibility and makes `SELECT ... FOR UPDATE OF` statements more reliable in queries that use table aliases. + + For more information, see the user documentation. + +### **DB operations** + +- Support specifying the maximum number of nodes for distributed execution tasks [#58937](https://github.com/pingcap/tidb/pull/58937) [@tangenta](https://github.com/tangenta), [@D3Hunter](https://github.com/D3Hunter) **tw@hfxsd** + + Before v8.5.6, TiDB did not support efficiently limiting how many nodes a distributed execution task could use. When you wanted to control resource usage for distributed task execution, TiDB did not provide a dedicated option to constrain the maximum node count. + + Starting from v8.5.6, TiDB supports the `tidb_max_dist_task_nodes` system variable, which lets you specify the maximum number of TiDB nodes used by a distributed execution task. This gives you more flexibility to manage resource usage and tune distributed task execution based on workload and cluster conditions. + + For more information, see the [user documentation](/system-variables.md#tidb_max_dist_task_nodes-new-in-v856). + ### Data Migration - (dup): release-9.0.0.md > # Data migration * Migrate sync-diff-inspector from `pingcap/tidb-tools` to `pingcap/tiflow` repository [#11672](https://github.com/pingcap/tiflow/issues/11672) @[joechenrh](https://github.com/joechenrh) ## Compatibility Changes -- note [#issue](https://github.com/pingcap/${repo-name}/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) +For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions earlier than v8.5.4), you can smoothly upgrade to v8.5.6. Most changes in v8.5.6 are safe for routine upgrades, but this release also includes several behavior changes, MySQL compatibility adjustments, system variable updates, configuration parameter updates, and system table changes. Before upgrading, make sure to carefully review this section. + +### Behavior changes + +### MySQL compatibility + +### System variables + +| Variable name | Change type | Description | +|--------|------------------------------|------| +| | | | +| | | | +| | | | + +### Configuration parameters + +| Configuration file or component | Configuration parameter | Change type | Description | +| -------- | -------- | -------- | -------- | +| | | | +| | | | +| | | | ## Improvements + TiDB -- Improve plan selection for queries with IN predicates on index prefix columns. TiDB can now leverage merge sort to preserve order in ORDER BY ... LIMIT queries, reducing unnecessary scans and improving performance.[#62694](https://github.com/pingcap/tidb/pull/62694) [@time-and-fate](https://github.com/time-and-fate)**tw@hfxsd** + + - Improve plan selection for queries with IN predicates on index prefix columns. TiDB can now leverage merge sort to preserve order in ORDER BY ... LIMIT queries, reducing unnecessary scans and improving performance.[#62694](https://github.com/pingcap/tidb/pull/62694) [@time-and-fate](https://github.com/time-and-fate)**tw@hfxsd** - Enhanced slow query log control by supporting [`tidb_slow_log_rules`](/system-variables.md#tidb_slow_log_rules-new-in-v900) for targeted slow query log output based on combinations of multiple metrics, [`tidb_slow_log_max_per_sec`](/system-variables.md#tidb_slow_log_max_per_sec-new-in-v900) for limiting the number of slow query log entries per second, and the [`WRITE_SLOW_LOG`](/identify-slow-queries.md#related-hint) hint for forcing specified SQL statements to be recorded in the slow query log [#64010](https://github.com/pingcap/tidb/issues/64010) @[zimulala](https://github.com/zimulala) - Enhanced [Top SQL](/dashboard/top-sql.md) for resource analysis by supporting Top `5`, `20`, or `100` queries, hotspot analysis sorted by CPU, network traffic, or logical I/O, and aggregated analysis by `Query`, `Table`, `DB`, or `Region` on TiKV instances [#62916](https://github.com/pingcap/tidb/issues/62916) @[yibin87](https://github.com/yibin87) - 新增 DXF 的 max_node_count 配置项支持 [#66376](https://github.com/pingcap/tidb/pull/66376)@[D3Hunter](https://github.com/D3Hunter) @@ -97,49 +131,30 @@ Starting from v8.5.6, TiDB supports the `tidb_max_dist_task_nodes` system variab + PD - - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - 删除不存在的 label 时，现在会返回 404 [#10089](https://github.com/tikv/pd/issues/10089) @[lhy1024](https://github.com/lhy1024) - (dup): release-7.5.7.md > Improvements> PD - Reduce unnecessary error logs [#9370](https://github.com/tikv/pd/issues/9370) @[bufferflies](https://github.com/bufferflies) + TiFlash - - note [#issue](https://github.com/pingcap/tiflash/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tiflash/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - + Tools + Backup & Restore (BR) - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - + TiCDC - - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - + TiDB Data Migration (DM) - - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - Support migrating data from MySQL 8.4 as a data source. The compatibility level for MySQL 8.4 is upgraded from "Incompatible" to "Experimental" [#11020](https://github.com/pingcap/tiflow/issues/11020) @[dveeden](https://github.com/dveeden) + - 在 DM syncer 中新增外键因果依赖支持，确保多 worker 场景下行变更按照父表至子表的外键顺序执行 [#12552](https://github.com/pingcap/tiflow/pull/12552) @[OliverS929](https://github.com/OliverS929) + TiDB Lightning - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - + Dumpling - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - Support exporting data from MySQL 8.4 by adopting the updated MySQL binary log terminology [#53082](https://github.com/pingcap/tidb/issues/53082) @[dveeden](https://github.com/dveeden) + TiUP - - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - ## Bug Fixes + TiDB @@ -173,8 +188,8 @@ Starting from v8.5.6, TiDB supports the `tidb_max_dist_task_nodes` system variab + PD - - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/tikv/pd/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - 修复 distribute table sql panic 问题，特别是 merge region operator 比较多的场景容易触发这个 bug。 [#10292](https://github.com/tikv/pd/pull/10292) @[bufferflies](https://github.com/bufferflies) + - 修复设置 store limit 后可能不马上生效的问题 [#10108](https://github.com/tikv/pd/issues/10108) @[okJiang](https://github.com/okJiang) + TiFlash @@ -186,7 +201,7 @@ Starting from v8.5.6, TiDB supports the `tidb_max_dist_task_nodes` system variab + Backup & Restore (BR) - - 修复了 log backup 的 flush_ts 可能为 0 的问题 [#19406](https://github.com/tikv/tikv/issues/19406) @[YuJuncen](https://github.com/YuJuncen) + - 修复 log backup 的 flush_ts 可能为 0 的问题 [#19406](https://github.com/tikv/tikv/issues/19406) @[YuJuncen](https://github.com/YuJuncen) - 修复 BR 在使用 GCP S3 API server 进行 multipart upload 时因缺少 `Content-Length` 头而失败的问题 [#19352](https://github.com/tikv/tikv/issues/19352) @[Leavrth](https://github.com/Leavrth) - 修复 BR `restore point` 可能长时间卡在 `waiting for schema info finishes reloading` 并在 15 分钟后超时失败的问题 [#66110](https://github.com/pingcap/tidb/issues/66110) @[kennytm](https://github.com/kennytm) - 修复 BR 在恢复带有 `SHARD_ROW_ID_BITS`、`PRE_SPLIT_REGIONS` 和 `merge_option` 属性的表时无法正确预分裂 Region 的问题 [#65060](https://github.com/pingcap/tidb/issues/65060) @[JoyC-dev](https://github.com/JoyC-dev) @@ -200,20 +215,12 @@ Starting from v8.5.6, TiDB supports the `tidb_max_dist_task_nodes` system variab + TiDB Data Migration (DM) - - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tiflow/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - 修复 DM 在 binlog rotate 事件时全局 checkpoint 位置未推进的问题 [#12525](https://github.com/pingcap/tiflow/pull/12525) @[OliverS929](https://github.com/OliverS929) + - 修复含外键约束的表在 DM safe-mode 下的异常行为，移除 UPDATE 改写中多余的 DELETE 操作并避免触发外键级联 [#12541](https://github.com/pingcap/tiflow/pull/12541) @[OliverS929](https://github.com/OliverS929) + - 修复 DM validator 对 UNSIGNED 列误报校验错误的问题 [#12555](https://github.com/pingcap/tiflow/pull/12555) @[OliverS929](https://github.com/OliverS929) + TiDB Lightning - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - + Dumpling - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tidb/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - + TiUP - - - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) - - note [#issue](https://github.com/pingcap/tiup/issues/${issue-id}) @[Contributor GitHub ID](https://github.com/${github-id}) + - 修复 Dumpling 与 MySQL 8.4 的兼容性问题 [#65131](https://github.com/pingcap/tidb/pull/65131) @[dveeden](https://github.com/dveeden) From 12bde21bd22395baed2877db467b8bdb0b8e6e7c Mon Sep 17 00:00:00 2001 From: houfaxin Date: Mon, 30 Mar 2026 10:36:51 +0800 Subject: [PATCH 20/26] assign tw --- releases/release-8.5.6.md | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 5e2de56546eb4..64f924dcc3f64 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -113,7 +113,7 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions ## Improvements -+ TiDB ++ TiDB - Improve plan selection for queries with IN predicates on index prefix columns. TiDB can now leverage merge sort to preserve order in ORDER BY ... LIMIT queries, reducing unnecessary scans and improving performance.[#62694](https://github.com/pingcap/tidb/pull/62694) [@time-and-fate](https://github.com/time-and-fate)**tw@hfxsd** - Enhanced slow query log control by supporting [`tidb_slow_log_rules`](/system-variables.md#tidb_slow_log_rules-new-in-v900) for targeted slow query log output based on combinations of multiple metrics, [`tidb_slow_log_max_per_sec`](/system-variables.md#tidb_slow_log_max_per_sec-new-in-v900) for limiting the number of slow query log entries per second, and the [`WRITE_SLOW_LOG`](/identify-slow-queries.md#related-hint) hint for forcing specified SQL statements to be recorded in the slow query log [#64010](https://github.com/pingcap/tidb/issues/64010) @[zimulala](https://github.com/zimulala) @@ -122,14 +122,14 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions - 调整部分 stats 相关日志为 warning 级别 [#58315](https://github.com/pingcap/tidb/pull/58315)@[hawkingrei](https://github.com/hawkingrei) - 调整 tidb_analyze_column_options 默认值为 all [#64992](https://github.com/pingcap/tidb/issues/64992) @[0xPoe](https://github.com/0xPoe) -+ TiKV ++ TiKV - Add MVCC-read-aware load-based compaction to prioritize regions with heavy MVCC read overhead. [#19133](https://github.com/tikv/tikv/issues/19133) @[mittalrishabh](https://github.com/mittalrishabh) - Optimize stale-range cleanup during scaling by deleting stale keys directly instead of ingesting SST files, reducing latency impact. [#18042](https://github.com/tikv/tikv/issues/18042) @[LykxSassinator](https://github.com/LykxSassinator) - Make default gRPC raft connection and concurrency settings scale with CPU quota to improve resource utilization. [#18613](https://github.com/tikv/tikv/issues/18613) @[LykxSassinator](https://github.com/LykxSassinator) - Add Top SQL support for collecting network traffic and logical I/O information to help diagnose SQL performance issues. [#18815](https://github.com/tikv/tikv/issues/18815) @[yibin87](https://github.com/yibin87) -+ PD ++ PD - 删除不存在的 label 时，现在会返回 404 [#10089](https://github.com/tikv/pd/issues/10089) @[lhy1024](https://github.com/lhy1024) - (dup): release-7.5.7.md > Improvements> PD - Reduce unnecessary error logs [#9370](https://github.com/tikv/pd/issues/9370) @[bufferflies](https://github.com/bufferflies) @@ -142,14 +142,14 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions + TiCDC - + TiDB Data Migration (DM) + + TiDB Data Migration (DM) - Support migrating data from MySQL 8.4 as a data source. The compatibility level for MySQL 8.4 is upgraded from "Incompatible" to "Experimental" [#11020](https://github.com/pingcap/tiflow/issues/11020) @[dveeden](https://github.com/dveeden) - 在 DM syncer 中新增外键因果依赖支持，确保多 worker 场景下行变更按照父表至子表的外键顺序执行 [#12552](https://github.com/pingcap/tiflow/pull/12552) @[OliverS929](https://github.com/OliverS929) + TiDB Lightning - + Dumpling + + Dumpling - Support exporting data from MySQL 8.4 by adopting the updated MySQL binary log terminology [#53082](https://github.com/pingcap/tidb/issues/53082) @[dveeden](https://github.com/dveeden) @@ -157,7 +157,7 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions ## Bug Fixes -+ TiDB ++ TiDB - Fix the issue that upgrading from release-8.5-20250606-v8.5.2 to upstream release-8.5 can skip PITR metadata upgrades and cause PITR operations to fail. [#66994](https://github.com/pingcap/tidb/issues/66994) @[fzzf678](https://github.com/fzzf678) - Fix the issue that after EXCHANGE PARTITION, non-unique or nullable unique global indexes on non-clustered partitioned tables can become inconsistent and return incomplete results. [#65289](https://github.com/pingcap/tidb/issues/65289) @[mjonss](https://github.com/mjonss) @@ -165,7 +165,7 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions - Improve the performance of privilege updates such as GRANT and REVOKE in deployments with large numbers of privilege entries. [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) - Fix the issue that KILL QUERY incorrectly kills idle connections. [#65447](https://github.com/pingcap/tidb/issues/65447) @[gengliqi](https://github.com/gengliqi) - Fix the issue that column-level privilege checks can be incorrect for JOIN ... USING, NATURAL JOIN, and INSERT ... ON DUPLICATE KEY UPDATE. [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) - - Improve privilege-check performance for deployments with many column-level privilege entries. [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) + - Improve privilege-check performance for deployments with many column-level privilege entries. [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) - Add cluster_id to mysql.tidb so external tools can determine whether two TiDB instances belong to the same cluster. [#59476](https://github.com/pingcap/tidb/issues/59476) @[YangKeao](https://github.com/YangKeao) - Improve the slow query log by printing non-printable prepared-statement arguments as hexadecimal literals. [#65383](https://github.com/pingcap/tidb/issues/65383) @[dveeden](https://github.com/dveeden) - 修复 tidb_service_scope 设置时未统一转换为小写的问题 [#66835](https://github.com/pingcap/tidb/pull/66835)@[D3Hunter](https://github.com/D3Hunter) @@ -175,7 +175,7 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions - 修复 stats delta 数据可能刷新不及时的问题 [#65426](https://github.com/pingcap/tidb/issues/65426) @[ti-chi-bot](https://github.com/ti-chi-bot) - 修复事务中第一条语句使用 fair locking 模式上锁时，有时可能使事务 keep alive 失效、并被意外回滚的问题 [#66571](https://github.com/pingcap/tidb/issues/66571) @[MyonKeminta](https://github.com/MyonKeminta) -+ TiKV ++ TiKV - Fix a memory leak in crossbeam skiplist. [#19285](https://github.com/tikv/tikv/issues/19285) @[ekexium](https://github.com/ekexium) - Fix the issue that global indexes on non-unique columns of partitioned tables might become inconsistent and return incorrect results in some cases. [#19262](https://github.com/tikv/tikv/issues/19262) @[mjonss](https://github.com/mjonss) @@ -186,12 +186,12 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions - Fix ingest latency spikes in large clusters by increasing the default `rocksdb.max-manifest-file-size` from 128 MiB to 256 MiB. [#18996](https://github.com/tikv/tikv/issues/18996) @[glorv](https://github.com/glorv) - (dup): release-5.1.4.md > Bug fixes> TiKV - Fix the rare data inconsistency issue when retrying a prewrite request in pessimistic transactions [#11187](https://github.com/tikv/tikv/issues/11187) -+ PD ++ PD - 修复 distribute table sql panic 问题，特别是 merge region operator 比较多的场景容易触发这个 bug。 [#10292](https://github.com/tikv/pd/pull/10292) @[bufferflies](https://github.com/bufferflies) - 修复设置 store limit 后可能不马上生效的问题 [#10108](https://github.com/tikv/pd/issues/10108) @[okJiang](https://github.com/okJiang) -+ TiFlash ++ TiFlash - 修复当一个列执行将列属性 `NOT NULL` 转为 `NULL` 的 DDL 之后，TiFlash 与 TiKV 之间可能产生不一致数据的问题 [#10680](https://github.com/pingcap/tiflash/issues/10680) @[JaySon-Huang](https://github.com/JaySon-Huang) - 修复 Grafana 面板中 Raft throughput 可能会错误地显示一个非常大的数值的问题 [#10701](https://github.com/pingcap/tiflash/issues/10701) @[CalvinNeo](https://github.com/CalvinNeo) @@ -199,21 +199,21 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions + Tools - + Backup & Restore (BR) + + Backup & Restore (BR) - 修复 log backup 的 flush_ts 可能为 0 的问题 [#19406](https://github.com/tikv/tikv/issues/19406) @[YuJuncen](https://github.com/YuJuncen) - 修复 BR 在使用 GCP S3 API server 进行 multipart upload 时因缺少 `Content-Length` 头而失败的问题 [#19352](https://github.com/tikv/tikv/issues/19352) @[Leavrth](https://github.com/Leavrth) - 修复 BR `restore point` 可能长时间卡在 `waiting for schema info finishes reloading` 并在 15 分钟后超时失败的问题 [#66110](https://github.com/pingcap/tidb/issues/66110) @[kennytm](https://github.com/kennytm) - 修复 BR 在恢复带有 `SHARD_ROW_ID_BITS`、`PRE_SPLIT_REGIONS` 和 `merge_option` 属性的表时无法正确预分裂 Region 的问题 [#65060](https://github.com/pingcap/tidb/issues/65060) @[JoyC-dev](https://github.com/JoyC-dev) - + TiCDC + + TiCDC - Fixed an issue where changefeed might repeatedly create invalid dispatchers when the server restarts. [#4452](https://github.com/pingcap/ticdc/issues/4452) @[wlwilliamx](https://github.com/wlwilliamx) - Fixed an issue where table renaming operations could not be performed normally when the upstream TiDB version was <= v8.1.x. [#4392](https://github.com/pingcap/ticdc/issues/4392) @[lidezhu](https://github.com/lidezhu) - Fixed a bug during data scanning to avoid potential abnormal crashes of TiKV when CDC is enabled. [#19404](https://github.com/tikv/tikv/issues/19404) @[wk989898](https://github.com/wk989898) - Supported Azure Managed Identity authentication for azblob sinks and fixed a potential stuck issue during cloud storage uploads. [#3093](https://github.com/pingcap/ticdc/issues/3093) @[wlwilliamx](https://github.com/wlwilliamx) - + TiDB Data Migration (DM) + + TiDB Data Migration (DM) - 修复 DM 在 binlog rotate 事件时全局 checkpoint 位置未推进的问题 [#12525](https://github.com/pingcap/tiflow/pull/12525) @[OliverS929](https://github.com/OliverS929) - 修复含外键约束的表在 DM safe-mode 下的异常行为，移除 UPDATE 改写中多余的 DELETE 操作并避免触发外键级联 [#12541](https://github.com/pingcap/tiflow/pull/12541) @[OliverS929](https://github.com/OliverS929) @@ -221,6 +221,6 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions + TiDB Lightning - + Dumpling + + Dumpling - 修复 Dumpling 与 MySQL 8.4 的兼容性问题 [#65131](https://github.com/pingcap/tidb/pull/65131) @[dveeden](https://github.com/dveeden) From 7e2eb8bedc9eb304f74ccc8836999668b7bb3c21 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Mon, 30 Mar 2026 15:06:56 +0800 Subject: [PATCH 21/26] Apply suggestions from code review --- releases/release-8.5.6.md | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 64f924dcc3f64..c2a1afee24190 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -25,13 +25,13 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti ### Stability -- The ability to set resource limits for background tasks in Resource Control is now Generally Available (GA) [#56019](https://github.com/pingcap/tidb/issues/56019) @[glorv](https://github.com/glorv) **tw@hfxsd** +- Support setting the maximum limit on resource usage for background tasks of resource control (GA) [#56019](https://github.com/pingcap/tidb/issues/56019) @[glorv](https://github.com/glorv) **tw@hfxsd** - TiDB Resource Control can identify and lower the priority of background tasks. In some scenarios, even with idle resources, users may want to keep the consumption of background tasks at a very low level. Starting from v8.4.0, you can use the `UTILIZATION_LIMIT` parameter to set the maximum percentage of resources that background tasks under Resource Control can use, controlling the usage of all background tasks on each node below this percentage. This feature allows you to finely control the resource consumption of background tasks, further enhancing cluster stability. + TiDB resource control can identify and lower the priority of background tasks. In certain scenarios, you might want to limit the resource consumption of background tasks, even when resources are available. Starting from v8.4.0, you can use the UTILIZATION_LIMIT parameter to set the maximum percentage of resources that background tasks can consume. Each node will keep the resource usage of all background tasks below this percentage. This feature enables precise control over resource consumption for background tasks, further enhancing cluster stability. - In v8.5.6, this feature is Generally Available (GA). + In v8.5.6, this feature is generally available (GA). - For more information, please refer to the [User Documentation](/tidb-resource-control-background-tasks.md). + For more information, see [User Documentation](/tidb-resource-control-background-tasks.md). ### 可观测性 @@ -59,9 +59,9 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti - Support column-level privilege management [#61706](https://github.com/pingcap/tidb/issues/61706) [@CbcWestwolf](https://github.com/CbcWestwolf),[@fzzf678](https://github.com/fzzf678) **tw@hfxsd** - Before v8.5.6, TiDB privilege control mainly covered the database, and table levels, and did not support granting or revoking privileges on specific columns as MySQL does. As a result, when you needed to restrict users to accessing only a subset of sensitive columns in a table, TiDB could not provide sufficiently fine-grained access control. + Before v8.5.6, TiDB privilege control covers the database and table levels and does not support granting or revoking privileges on specific columns, unlike MySQL. As a result, you cannot restrict users to access only a subset of sensitive columns in a table. - Starting from v8.5.6, TiDB supports column-level privilege management. You can use the `GRANT` and `REVOKE` statements to grant or revoke privileges on specific columns, and TiDB performs privilege checks based on column privileges during query processing and execution plan construction. This enables more fine-grained access control and better supports sensitive data isolation and the principle of least privilege. + Starting from v8.5.6, TiDB supports column-level privilege management. You can use the `GRANT` and `REVOKE` statements to manage privileges on specific columns. TiDB performs privilege checks based on column-level privileges during query processing and execution plan construction, enabling finer-grained access control and better support for sensitive data isolation and the principle of least privilege. For more information, see the [user documentation](/column-privilege-management.md). @@ -75,11 +75,11 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti ### **DB operations** -- Support specifying the maximum number of nodes for distributed execution tasks [#58937](https://github.com/pingcap/tidb/pull/58937) [@tangenta](https://github.com/tangenta), [@D3Hunter](https://github.com/D3Hunter) **tw@hfxsd** +- Support specifying the maximum number of nodes for Distributed eXecution Framework (DXF) tasks [#58937](https://github.com/pingcap/tidb/pull/58937) [@tangenta](https://github.com/tangenta), [@D3Hunter](https://github.com/D3Hunter) **tw@hfxsd** - Before v8.5.6, TiDB did not support efficiently limiting how many nodes a distributed execution task could use. When you wanted to control resource usage for distributed task execution, TiDB did not provide a dedicated option to constrain the maximum node count. + Before v8.5.6, TiDB does not provide a way to limit the number of nodes used by a distributed execution task. When you want to control resource usage for DXF, TiDB does not provide a dedicated option to constrain the maximum node count. - Starting from v8.5.6, TiDB supports the `tidb_max_dist_task_nodes` system variable, which lets you specify the maximum number of TiDB nodes used by a distributed execution task. This gives you more flexibility to manage resource usage and tune distributed task execution based on workload and cluster conditions. + Starting from v8.5.6, TiDB introduces the `tidb_max_dist_task_nodes` system variable to specify the maximum number of TiDB nodes used by a DXF task, enabling better resource control and workload-based tuning. For more information, see the [user documentation](/system-variables.md#tidb_max_dist_task_nodes-new-in-v856). From afad711f65df32030222dd33fb891a26e2298065 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Mon, 30 Mar 2026 15:32:58 +0800 Subject: [PATCH 22/26] Update releases/release-8.5.6.md --- releases/release-8.5.6.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index c2a1afee24190..82ef277bd8688 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -115,7 +115,7 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions + TiDB - - Improve plan selection for queries with IN predicates on index prefix columns. TiDB can now leverage merge sort to preserve order in ORDER BY ... LIMIT queries, reducing unnecessary scans and improving performance.[#62694](https://github.com/pingcap/tidb/pull/62694) [@time-and-fate](https://github.com/time-and-fate)**tw@hfxsd** + - Improve plan selection for queries with `IN` predicates on index prefix columns. TiDB can now use merge sort to preserve order for `ORDER BY ... LIMIT` queries, reducing unnecessary scans and improving performance. [#63449](https://github.com/pingcap/tidb/issues/63449) [#34882](https://github.com/pingcap/tidb/issues/34882) [@time-and-fate](https://github.com/time-and-fate) **tw@hfxsd** - Enhanced slow query log control by supporting [`tidb_slow_log_rules`](/system-variables.md#tidb_slow_log_rules-new-in-v900) for targeted slow query log output based on combinations of multiple metrics, [`tidb_slow_log_max_per_sec`](/system-variables.md#tidb_slow_log_max_per_sec-new-in-v900) for limiting the number of slow query log entries per second, and the [`WRITE_SLOW_LOG`](/identify-slow-queries.md#related-hint) hint for forcing specified SQL statements to be recorded in the slow query log [#64010](https://github.com/pingcap/tidb/issues/64010) @[zimulala](https://github.com/zimulala) - Enhanced [Top SQL](/dashboard/top-sql.md) for resource analysis by supporting Top `5`, `20`, or `100` queries, hotspot analysis sorted by CPU, network traffic, or logical I/O, and aggregated analysis by `Query`, `Table`, `DB`, or `Region` on TiKV instances [#62916](https://github.com/pingcap/tidb/issues/62916) @[yibin87](https://github.com/yibin87) - 新增 DXF 的 max_node_count 配置项支持 [#66376](https://github.com/pingcap/tidb/pull/66376)@[D3Hunter](https://github.com/D3Hunter) From cee81a1fc44fc7de516a003aa87bca58e0586fd1 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Mon, 30 Mar 2026 17:12:22 +0800 Subject: [PATCH 23/26] Update releases/release-8.5.6.md --- releases/release-8.5.6.md | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 82ef277bd8688..dd6417644357d 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -166,14 +166,13 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions - Fix the issue that KILL QUERY incorrectly kills idle connections. [#65447](https://github.com/pingcap/tidb/issues/65447) @[gengliqi](https://github.com/gengliqi) - Fix the issue that column-level privilege checks can be incorrect for JOIN ... USING, NATURAL JOIN, and INSERT ... ON DUPLICATE KEY UPDATE. [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) - Improve privilege-check performance for deployments with many column-level privilege entries. [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) - - Add cluster_id to mysql.tidb so external tools can determine whether two TiDB instances belong to the same cluster. [#59476](https://github.com/pingcap/tidb/issues/59476) @[YangKeao](https://github.com/YangKeao) - - Improve the slow query log by printing non-printable prepared-statement arguments as hexadecimal literals. [#65383](https://github.com/pingcap/tidb/issues/65383) @[dveeden](https://github.com/dveeden) - - 修复 tidb_service_scope 设置时未统一转换为小写的问题 [#66835](https://github.com/pingcap/tidb/pull/66835)@[D3Hunter](https://github.com/D3Hunter) - - 修复 TiDB 重启后无法展示亲和力表的问题 [#66284](https://github.com/pingcap/tidb/issues/66284) @[lcwangchao](https://github.com/lcwangchao) - - 修复可能出现的内存泄漏 [#65522](https://github.com/pingcap/tidb/issues/65522) @[bufferflies](https://github.com/bufferflies) - - 修复系统表可能影响 stats healthy 监控的问题 [#64080](https://github.com/pingcap/tidb/issues/64080) @[ti-chi-bot](https://github.com/ti-chi-bot) - - 修复 stats delta 数据可能刷新不及时的问题 [#65426](https://github.com/pingcap/tidb/issues/65426) @[ti-chi-bot](https://github.com/ti-chi-bot) - - 修复事务中第一条语句使用 fair locking 模式上锁时，有时可能使事务 keep alive 失效、并被意外回滚的问题 [#66571](https://github.com/pingcap/tidb/issues/66571) @[MyonKeminta](https://github.com/MyonKeminta) + - Add `cluster_id` to `mysql.tidb`, enabling external tools to determine whether two TiDB instances belong to the same cluster [#59476](https://github.com/pingcap/tidb/issues/59476) @[YangKeao](https://github.com/YangKeao) + - Improve slow query log readability by outputting non-printable prepared statement arguments as hexadecimal values [#65383](https://github.com/pingcap/tidb/issues/65383) @[dveeden](https://github.com/dveeden) + - Fix the issue that the value of `tidb_service_scope` is not converted to lowercase when set [#66749](https://github.com/pingcap/tidb/issues/66749) @[D3Hunter](https://github.com/D3Hunter) + - Fix the issue that affinity tables are not displayed after TiDB restarts [#66284](https://github.com/pingcap/tidb/issues/66284) @[lcwangchao](https://github.com/lcwangchao) + - Fix the issue that the Stats Healthy metric displays inaccurately because system tables are not excluded from the stats cache [#64080](https://github.com/pingcap/tidb/issues/64080) @[ti-chi-bot](https://github.com/ti-chi-bot) + - Fix the issue that statistics might not be updated due to abnormal updates of `modify_count` [#65426](https://github.com/pingcap/tidb/issues/65426) @[ti-chi-bot](https://github.com/ti-chi-bot) + - Fix the issue that a pessimistic transaction might be unexpectedly rolled back due to a keep-alive mechanism failure when its first statement acquires locks in fair locking mode [#66571](https://github.com/pingcap/tidb/issues/66571) @[MyonKeminta](https://github.com/MyonKeminta) + TiKV From b5ae92445e8a76c211657c00772e6b7280ba4266 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Mon, 30 Mar 2026 17:23:39 +0800 Subject: [PATCH 24/26] Apply suggestions from code review --- releases/release-8.5.6.md | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index dd6417644357d..cc2117526bfdc 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -187,14 +187,14 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions + PD - - 修复 distribute table sql panic 问题，特别是 merge region operator 比较多的场景容易触发这个 bug。 [#10292](https://github.com/tikv/pd/pull/10292) @[bufferflies](https://github.com/bufferflies) - - 修复设置 store limit 后可能不马上生效的问题 [#10108](https://github.com/tikv/pd/issues/10108) @[okJiang](https://github.com/okJiang) + - Fix a panic issue that might occur when executing `DISTRIBUTE TABLE` in scenarios with a large number of Merge Region operators [#10292](https://github.com/tikv/pd/pull/10292) @[bufferflies](https://github.com/bufferflies) + - Fix the issue that configuring Store Limit might not take effect immediately [#10108](https://github.com/tikv/pd/issues/10108) @[okJiang](https://github.com/okJiang) + TiFlash - - 修复当一个列执行将列属性 `NOT NULL` 转为 `NULL` 的 DDL 之后，TiFlash 与 TiKV 之间可能产生不一致数据的问题 [#10680](https://github.com/pingcap/tiflash/issues/10680) @[JaySon-Huang](https://github.com/JaySon-Huang) - - 修复 Grafana 面板中 Raft throughput 可能会错误地显示一个非常大的数值的问题 [#10701](https://github.com/pingcap/tiflash/issues/10701) @[CalvinNeo](https://github.com/CalvinNeo) - - 修复 runtime filter 开启情况下，如果 join key 数据类型不一致时，join 结果可能出错的问题 [#10699](https://github.com/pingcap/tiflash/issues/10699) @[ChangRui-Ryan](https://github.com/ChangRui-Ryan) + - Fix a potential data inconsistency issue between TiFlash and TiKV after executing a DDL statement to remove the `NOT NULL` constraint of a column [#10680](https://github.com/pingcap/tiflash/issues/10680) @[JaySon-Huang](https://github.com/JaySon-Huang) + - Fix the issue that the Raft throughput metric in the Grafana dashboard might display an abnormally large value [#10701](https://github.com/pingcap/tiflash/issues/10701) @[CalvinNeo](https://github.com/CalvinNeo) + - Fix an issue that the Join result might be incorrect when the Runtime Filter is enabled and the Join Keys have inconsistent data types [#10699](https://github.com/pingcap/tiflash/issues/10699) @[ChangRui-Ryan](https://github.com/ChangRui-Ryan) + Tools From 6bd03851047ef59abbc5d04778d1701d0fc433b3 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Mon, 30 Mar 2026 17:56:46 +0800 Subject: [PATCH 25/26] Update releases/release-8.5.6.md --- releases/release-8.5.6.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index cc2117526bfdc..4f82f1a6390f0 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -27,7 +27,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti - Support setting the maximum limit on resource usage for background tasks of resource control (GA) [#56019](https://github.com/pingcap/tidb/issues/56019) @[glorv](https://github.com/glorv) **tw@hfxsd** - TiDB resource control can identify and lower the priority of background tasks. In certain scenarios, you might want to limit the resource consumption of background tasks, even when resources are available. Starting from v8.4.0, you can use the UTILIZATION_LIMIT parameter to set the maximum percentage of resources that background tasks can consume. Each node will keep the resource usage of all background tasks below this percentage. This feature enables precise control over resource consumption for background tasks, further enhancing cluster stability. + TiDB resource control can identify and lower the priority of background tasks. In certain scenarios, you might want to limit the resource consumption of background tasks, even when resources are available. Starting from v8.4.0, you can use the `UTILIZATION_LIMIT` parameter to set the maximum percentage of resources that background tasks can consume. Each node will keep the resource usage of all background tasks below this percentage. This feature enables precise control over resource consumption for background tasks, further enhancing cluster stability. In v8.5.6, this feature is generally available (GA). From 46d142252322f587fb343cc8af30f951bf900505 Mon Sep 17 00:00:00 2001 From: xixirangrang Date: Mon, 30 Mar 2026 18:03:16 +0800 Subject: [PATCH 26/26] Apply suggestions from code review --- releases/release-8.5.6.md | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/releases/release-8.5.6.md b/releases/release-8.5.6.md index 4f82f1a6390f0..682dcb2592d14 100644 --- a/releases/release-8.5.6.md +++ b/releases/release-8.5.6.md @@ -55,9 +55,9 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti 更多信息，请参考 [用户文档](/dashboard/top-sql.md)。 -### **SQL** +### SQL -- Support column-level privilege management [#61706](https://github.com/pingcap/tidb/issues/61706) [@CbcWestwolf](https://github.com/CbcWestwolf),[@fzzf678](https://github.com/fzzf678) **tw@hfxsd** +- Support column-level privilege management [#61706](https://github.com/pingcap/tidb/issues/61706) @[CbcWestwolf](https://github.com/CbcWestwolf) @[fzzf678](https://github.com/fzzf678) **tw@hfxsd** Before v8.5.6, TiDB privilege control covers the database and table levels and does not support granting or revoking privileges on specific columns, unlike MySQL. As a result, you cannot restrict users to access only a subset of sensitive columns in a table. @@ -65,7 +65,7 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti For more information, see the [user documentation](/column-privilege-management.md). - - Support table aliases referenced in the `FOR UPDATE OF` clause [#65532](https://github.com/pingcap/tidb/pull/65532) [@cryo-zd](https://github.com/cryo-zd) **tw@lilin90** + - Support table aliases referenced in the `FOR UPDATE OF` clause [#65532](https://github.com/pingcap/tidb/pull/65532) @[cryo-zd](https://github.com/cryo-zd) **tw@lilin90** Before v8.5.6, when a `SELECT ... FOR UPDATE OF
` statement referenced a table alias in the locking clause, TiDB could fail to resolve the alias correctly and return a `table not exists` error even though the alias was valid. @@ -73,9 +73,9 @@ Try it out: [Quick Start](https://docs.pingcap.com/tidb/v8.5/quick-start-with-ti For more information, see the user documentation. -### **DB operations** +### DB operations -- Support specifying the maximum number of nodes for Distributed eXecution Framework (DXF) tasks [#58937](https://github.com/pingcap/tidb/pull/58937) [@tangenta](https://github.com/tangenta), [@D3Hunter](https://github.com/D3Hunter) **tw@hfxsd** +- Support specifying the maximum number of nodes for Distributed eXecution Framework (DXF) tasks [#58937](https://github.com/pingcap/tidb/pull/58937) @[tangenta](https://github.com/tangenta) @[D3Hunter](https://github.com/D3Hunter) **tw@hfxsd** Before v8.5.6, TiDB does not provide a way to limit the number of nodes used by a distributed execution task. When you want to control resource usage for DXF, TiDB does not provide a dedicated option to constrain the maximum node count. @@ -115,7 +115,7 @@ For TiDB clusters newly deployed in v8.5.5 (that is, not upgraded from versions + TiDB - - Improve plan selection for queries with `IN` predicates on index prefix columns. TiDB can now use merge sort to preserve order for `ORDER BY ... LIMIT` queries, reducing unnecessary scans and improving performance. [#63449](https://github.com/pingcap/tidb/issues/63449) [#34882](https://github.com/pingcap/tidb/issues/34882) [@time-and-fate](https://github.com/time-and-fate) **tw@hfxsd** + - Improve plan selection for queries with `IN` predicates on index prefix columns. TiDB can now use merge sort to preserve order for `ORDER BY ... LIMIT` queries, reducing unnecessary scans and improving performance. [#63449](https://github.com/pingcap/tidb/issues/63449) [#34882](https://github.com/pingcap/tidb/issues/34882) @[time-and-fate](https://github.com/time-and-fate) **tw@hfxsd** - Enhanced slow query log control by supporting [`tidb_slow_log_rules`](/system-variables.md#tidb_slow_log_rules-new-in-v900) for targeted slow query log output based on combinations of multiple metrics, [`tidb_slow_log_max_per_sec`](/system-variables.md#tidb_slow_log_max_per_sec-new-in-v900) for limiting the number of slow query log entries per second, and the [`WRITE_SLOW_LOG`](/identify-slow-queries.md#related-hint) hint for forcing specified SQL statements to be recorded in the slow query log [#64010](https://github.com/pingcap/tidb/issues/64010) @[zimulala](https://github.com/zimulala) - Enhanced [Top SQL](/dashboard/top-sql.md) for resource analysis by supporting Top `5`, `20`, or `100` queries, hotspot analysis sorted by CPU, network traffic, or logical I/O, and aggregated analysis by `Query`, `Table`, `DB`, or `Region` on TiKV instances [#62916](https://github.com/pingcap/tidb/issues/62916) @[yibin87](https://github.com/yibin87) - 新增 DXF 的 max_node_count 配置项支持 [#66376](https://github.com/pingcap/tidb/pull/66376)@[D3Hunter](https://github.com/D3Hunter)