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markdown-pages/en/tidb/master/releases/release-8.4.0.md

@@ -23,7 +23,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.4/quick-start-with-
 </thead>
 <tbody>
   <tr>
-    <td rowspan="5">Scalability and Performance</td>
+    <td rowspan="4">Scalability and Performance</td>
     <td><a href="https://docs.pingcap.com/tidb/v8.4/system-variables#tidb_enable_instance_plan_cache-new-in-v840">Instance-level execution plan cache</a> (experimental)**tw@Oreoxmt 1569**</td>
     <td>Instance-level execution plan cache allows all sessions within the same TiDB instance to share the execution plan cache. It stores more execution plans in memory, eliminating SQL compilation time. This reduces SQL execution time, improves OLTP system performance and throughput, and provides better control over memory usage, enhancing database stability.</td>
   </tr>
@@ -62,10 +62,14 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.4/quick-start-with-
     <td>Vector search is a search method based on data semantics, which provides more relevant search results. As one of the core functions of AI and large language models (LLMs), vector search can be used in various scenarios such as Retrieval-Augmented Generation (RAG), semantic search, and recommendation systems.</td>
   </tr>
   <tr>
-    <td rowspan="2">DB Operations and Observability</td>
+    <td rowspan="3">DB Operations and Observability</td>
     <td>Display TiKV and TiDB CPU times in memory tables**tw@hfxsd 1877**</td>
     <td>The CPU time is now integrated into a system table, displayed alongside other metrics for sessions or SQL, letting you observe high CPU consumption operations from multiple perspectives, and improves diagnostic efficiency. This is especially useful for diagnosing scenarios such as CPU spikes in instances or read/write hotspots in clusters.</td>
   </tr>
+  <tr>
+    <td>Support viewing aggregated TiKV CPU time by table or database **tw@lilin90 1878**</td>
+    <td>When hotspot issues are not caused by individual SQL statements, using the aggregated CPU time by table or database level in <a href="https://docs.pingcap.com/zh/tidb/v8.4/top-sql">TOP SQL</a> can help you quickly identify the tables or applications responsible for the hotspots, significantly improving the efficiency of diagnosing hotspot and CPU consumption issues.</td>
+  </tr>
   <tr>
     <td>Support backing up TiKV instances with IMDSv2 service enabled**tw@hfxsd 1945**</td>
     <td><a href="https://aws.amazon.com/cn/blogs/security/get-the-full-benefits-of-imdsv2-and-disable-imdsv1-across-your-aws-infrastructure/">AWS EC2 now uses IMDSv2 as the default metadata service</a>. TiDB supports backing up data from TiKV instances that have IMDSv2 enabled, helping you run TiDB clusters more effectively in public cloud services.</td>
@@ -182,7 +186,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.4/quick-start-with-
 
 * Support setting the maximum limit on resource usage for background tasks of resource control [#56019](https://github.com/pingcap/tidb/issues/56019) @[glorv](https://github.com/glorv) **tw@hfxsd** <!--1909-->
 
-    TiDB resource control can identify and lower the priority of background tasks. In certain scenarios, you might want to limit the resource consumption of these tasks, even when resources are available. Starting from v8.4.0, you can use the `UTILIZATION_LIMIT` parameter to set a maximum percentage of resources that a background task can consume. Each node will ensure that the resource usage of all background tasks stays within this limit. This feature enables precise control over resource consumption for background tasks, 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.
 
     For more information, see [documentation](/tidb-resource-control.md#manage-background-tasks).
 
@@ -254,15 +258,15 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.4/quick-start-with-
 
 ### Observability
 
-* Display the CPU time of TiDB and TiKV in the system table [#55542](https://github.com/pingcap/tidb/issues/55542) @[yibin87](https://github.com/yibin87) **tw@hfxsd** <!--1877-->
+* Display the CPU time consumed by TiDB and TiKV in the system table [#55542](https://github.com/pingcap/tidb/issues/55542) @[yibin87](https://github.com/yibin87) **tw@hfxsd** <!--1877-->
 
-      The [Top SQL page](/dashboard/top-sql.md) of [TiDB Dashboard](/dashboard/dashboard-intro.md) displays SQL statements with high CPU consumption. Starting from v8.4.0, TiDB includes CPU time consumption data in the system table, alongside other session or SQL metrics, allowing you to easily monitor high CPU usage from multiple perspectives. This information is especially useful in identifying the root cause of issues such as CPU spikes or hotspots in cluster read/write operations.
+    The [Top SQL page](/dashboard/top-sql.md) of [TiDB Dashboard](/dashboard/dashboard-intro.md) displays SQL statements with high CPU consumption. Starting from v8.4.0, TiDB adds CPU time consumption information to the system table, presented alongside other metrics for sessions or SQL, making it easier to observe high CPU consumption operations from multiple perspectives. This information can help you quickly identify the causes of issues in scenarios like instance CPU spikes or read/write hotspots in clusters.
 
-    - [STATEMENTS_SUMMARY](/statement-summary-tables.md) adds `AVG_TIDB_CPU_TIME` and `AVG_TIKV_CPU_TIME` to show the average CPU time consumed by individual SQL statements historically.
-    - [INFORMATION_SCHEMA.PROCESSLIST](/information-schema/information-schema-processlist.md) adds `TIDB_CPU` and `TIKV_CPU` to display the cumulative CPU consumption of currently executing SQL statements in a session.
-    - The [slow Log](/analyze-slow-queries.md) adds the `Tidb_cpu_time` and `Tikv_cpu_time` fields to show the CPU time of captured SQL statements.
+    - The [statement summary tables](/statement-summary-tables.md) add `AVG_TIDB_CPU_TIME` and `AVG_TIKV_CPU_TIME`, showing the average CPU time consumed by individual SQL statements historically.
+    - The [INFORMATION_SCHEMA.PROCESSLIST](/information-schema/information-schema-processlist.md) table adds `TIDB_CPU` and `TIKV_CPU`, showing the cumulative CPU consumption of the SQL statements currently being executed in a session.
+    - The [slow query Log](/analyze-slow-queries.md) adds the `Tidb_cpu_time` and `Tikv_cpu_time` fields, showing the CPU time of captured SQL statements.
 
-  By default, TiKV CPU time is displayed. Collecting TiDB CPU time introduces an additional overhead (about 8%), so TiDB CPU time is only displayed as the actual value when the [Top SQL feature](https://github.com/dashboard/top-sql.md) is enabled; otherwise, it will always display as `0`.
+  By default, the CPU time consumed by TiKV is displayed. Collecting the CPU time consumed by TiDB brings additional overhead (about 8%), so the CPU time consumed by TiDB only shows the actual value when [Top SQL](https://github.com/dashboard/top-sql.md) is enabled; otherwise, it always show as `0`.
 
     For more information, see [documentation](/information-schema/information-schema-processlist.md) and [documentation](information-schema/information-schema-slow-query.md).
 
@@ -276,7 +280,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.4/quick-start-with-
 
 * BR supports AWS IMDSv2 [#16443](https://github.com/tikv/tikv/issues/16443) @[pingyu](https://github.com/pingyu) **tw@hfxsd** <!--1945-->
 
-    BR now supports AWS Instance Metadata Service Version 2 (IMDSv2) when deployed on AWS EC2. This allows you to configure the newer session-oriented method on EC2 instances, enabling BR to successfully use the instance's associated IAM role to access AWS S3 with the appropriate privileges.
+    When deploying TiDB on Amazon EC2, BR supports AWS Instance Metadata Service Version 2 (IMDSv2). You can configure your EC2 instance to allow BR to use the IAM role associated with the instance for appropriate permissions to access Amazon S3.
 
     For more information, see [documentation](/backup-and-restore-storages#authentication).
 
@@ -373,7 +377,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.4/quick-start-with-
 
   - Increase the default value of Region from 96 MiB to 256 MiB to avoid the extra overhead caused by too many Regions [#17309](https://github.com/tikv/tikv/issues/17309) [LykxSassinator](https://github.com/LykxSassinator) **tw@hfxsd** <!--1925-->
   - Support setting memory usage limits for in-memory pessimistic locks in a Region or TiKV instance. To prevent CPU/IO overhead caused by pessimistic locks spilling to disk during write hotspots, you can increase the memory limit by modifying the configuration items [#17542](https://github.com/tikv/tikv/issues/17542) @[cfzjywxk](https://github.com/cfzjywxk) **tw@Oreoxmt** <!--1967-->
-  - Introduce a new `spill-dir` configuration in Raft Engine to support multi-disk storage for Raft logs. When the disk containing the home directory (`dir`) runs out of space, Raft Engine automatically writes new logs to `spill-dir`, ensuring continuous operation. [LykxSassinator](https://github.com/LykxSassinator) **tw@hfxsd** <!--1970-->
+  - Introduce a new `spill-dir` configuration item in Raft Engine, supporting multi-disk storage for Raft logs; when the disk where the home directory (`dir`) is located runs out of space, the Raft Engine automatically writes new logs to `spill-dir`, ensuring continuous operation of the system [#17356](https://github.com/tikv/tikv/issues/17356) [LykxSassinator](https://github.com/LykxSassinator) **tw@hfxsd** <!--1970-->
 
 + PD