Add TiDB v5.4 release notes (#7430)

TOC.md

@@ -672,6 +672,8 @@
 - Release Notes
   - [All Releases](/releases/release-notes.md)
   - [Release Timeline](/releases/release-timeline.md)
+  - v5.4
+    - [5.4.0](/releases/release-5.4.0.md)
   - v5.3
     - [5.3.0](/releases/release-5.3.0.md)
   - v5.2

_index.md

@@ -15,7 +15,7 @@ Designed for the cloud, TiDB provides flexible scalability, reliability and secu
 
 - [TiDB Introduction](/overview.md)
 - [Basic Features](/basic-features.md)
-- [TiDB 5.3 Release Notes](/releases/release-5.3.0.md)
+- [TiDB 5.4 Release Notes](/releases/release-5.4.0.md)
 - [TiDB Release Timeline](/releases/release-timeline.md)
 - [Compatibility with MySQL](/mysql-compatibility.md)
 - [Usage Limitations](/tidb-limitations.md)

experimental-features.md

@@ -7,6 +7,13 @@ summary: Learn the experimental features of TiDB.
 
 This document introduces the experimental features of TiDB in different versions. It is **NOT** recommended to use these features in the production environment.
 
+## Performance
+
++ [Automatically scale TiFlash thread pool](/tiflash/tiflash-configuration.md). (Introduced in v5.4)
++ [Raft Engine](/tikv-configuration-file.md#raft-engine). (Introduced in v5.4)
++ [Support collecting statistics for `PREDICATE COLUMNS`](/statistics.md#collect-statistics-on-some-columns) (Introduced in v5.4)
++ [Support synchronously loading statistics](/statistics.md#load-statistics). (Introduced in v5.4)
+
 ## Stability
 
 + TiFlash limits the use of I/O resources by compressing or sorting data, mitigating the contention for I/O resources between background tasks and front-end data reading and writing (Introduced in v5.0)
@@ -46,10 +53,6 @@ This document introduces the experimental features of TiDB in different versions
 + [Titan Level Merge](/storage-engine/titan-configuration.md#level-merge-experimental) (Introduced in v4.0)
 + TiFlash supports distributing the new data of the storage engine on multiple hard drives to share the I/O pressure. (Introduced in v4.0)
 
-## Data migration
-
-+ [DM OpenAPI](/dm/dm-open-api.md) (Introduced in v5.3)
-
 ## Backup and restoration
 
 + [Back up Raw KV](/br/use-br-command-line-tool.md#back-up-raw-kv-experimental-feature) (Introduced in v3.1)
@@ -63,4 +66,5 @@ This document introduces the experimental features of TiDB in different versions
 + [SQL diagnostics](/information-schema/information-schema-sql-diagnostics.md) (Introduced in v4.0)
 + [Cluster diagnostics](/dashboard/dashboard-diagnostics-access.md) (Introduced in v4.0)
 + [Continuous profiling](/dashboard/continuous-profiling.md) (Introduced in v5.3)
-+ [Online Unsafe Recovery](/online-unsafe-recovery.md) (Introduced in v5.3)
++ [Online Unsafe Recovery](/online-unsafe-recovery.md) (Introduced in v5.3)
++ [Top SQL](/dashboard/top-sql.md) (Introduced in v5.4)

pd-control.md

@@ -27,7 +27,7 @@ If you want to download the latest version of `pd-ctl`, directly download the Ti
 
 > **Note:**
 >
-> `{version}` indicates the version number of TiDB. For example, if `{version}` is `v5.3.0`, the package download link is `https://download.pingcap.org/tidb-v5.3.0-linux-amd64.tar.gz`.
+> `{version}` indicates the version number of TiDB. For example, if `{version}` is `v5.4.0`, the package download link is `https://download.pingcap.org/tidb-v5.4.0-linux-amd64.tar.gz`.
 
 ### Compile from source code
 

pd-recover.md

@@ -26,7 +26,7 @@ To download the latest version of PD Recover, directly download the TiDB package
 
 > **Note:**
 >
-> `{version}` indicates the version number of TiDB. For example, if `{version}` is `v5.3.0`, the package download link is `https://download.pingcap.org/tidb-v5.3.0-linux-amd64.tar.gz`.
+> `{version}` indicates the version number of TiDB. For example, if `{version}` is `v5.4.0`, the package download link is `https://download.pingcap.org/tidb-v5.4.0-linux-amd64.tar.gz`.
 
 ## Quick Start
 

releases/release-timeline.md

@@ -9,6 +9,7 @@ This document shows all the released TiDB versions in reverse chronological orde
 
 | Version | Release Date |
 | :--- | :--- |
+| [5.4.0](/releases/release-5.4.0.md) | 2022-02-15 |
 | [5.0.6](/releases/release-5.0.6.md) | 2021-12-31 |
 | [4.0.16](/releases/release-4.0.16.md) | 2021-12-17 |
 | [5.1.3](/releases/release-5.1.3.md) | 2021-12-03 |

tikv-configuration-file.md

@@ -608,6 +608,13 @@ Configuration items related to Raftstore.
 + Default value: `"4h"`
 + Minimum value: `0`
 
+## `snap-generator-pool-size` <span class="version-mark">New in v5.4.0</span>
+
++ Configures the size of the `snap-generator` thread pool.
++ To make Regions generate snapshot faster in TiKV in recovery scenarios, you need to increase the count of the `snap-generator` threads of the corresponding worker. You can use this configuration item to increase the size of the `snap-generator` thread pool.
++ Default value: `2`
++ Minimum value: `0`
+
 ### `lock-cf-compact-interval`
 
 + The time interval at which TiKV triggers a manual compaction for the Lock Column Family