[main] Copy v21.0.1 release notes (#17324)

Signed-off-by: Rohit Nayak <[email protected]>
Co-authored-by: Rohit Nayak <[email protected]>

changelog/21.0/21.0.0/summary.md

@@ -9,6 +9,7 @@
         - [Deprecated VTTablet Flags](#vttablet-flags)
         - [Deletion of deprecated metrics](#metric-deletion)
         - [Deprecated Metrics](#deprecations-metrics)
+    - **[RPC Changes](#rpc-changes)**
     - **[Traffic Mirroring](#traffic-mirroring)**
     - **[Atomic Distributed Transaction Support](#atomic-transaction)**
     - **[New VTGate Shutdown Behavior](#new-vtgate-shutdown-behavior)**
@@ -77,6 +78,12 @@ The following metrics are now deprecated and will be deleted in a future release
 | `vttablet` |   `QueryCacheHits`    |   `QueryEnginePlanCacheHits`    |
 | `vttablet` |  `QueryCacheMisses`   |  `QueryEnginePlanCacheMisses`   |
 
+### <a id="rpc-changes"/>RPC Changes</a>
+
+These are the RPC changes made in this release - 
+1. `ReadReparentJournalInfo` RPC has been added in TabletManagerClient interface, that is going to be used in EmergencyReparentShard for better errant GTID detection.
+2. `PrimaryStatus` RPC in TabletManagerClient interface has been updated to also return the server UUID of the primary. This is going to be used in the vttablets so that they can do their own errant GTID detection in `SetReplicationSource`.
+
 ### <a id="traffic-mirroring"/>Traffic Mirroring</a>
 
 Traffic mirroring is intended to help reduce some of the uncertainty inherent to `MoveTables SwitchTraffic`. When

changelog/21.0/21.0.1/changelog.md

@@ -0,0 +1,57 @@
+# Changelog of Vitess v21.0.1
+
+### Bug fixes 
+#### Backup and Restore
+ * [release-21.0] Fix how we cancel the context in the builtin backup engine (#17285) [#17291](https://github.com/vitessio/vitess/pull/17291)
+ * [release-21.0] S3: optional endpoint resolver and correct retrier [#17307](https://github.com/vitessio/vitess/pull/17307) 
+#### Cluster management
+ * [release-21.0] Fix panic in vttablet when closing topo server twice (#17094) [#17122](https://github.com/vitessio/vitess/pull/17122) 
+#### Online DDL
+ * [release-21.0] Online DDL: fix defer function, potential connection pool exhaustion (#17207) [#17210](https://github.com/vitessio/vitess/pull/17210) 
+#### Query Serving
+ * [release-21.0] bugfix: treat EXPLAIN like SELECT (#17054) [#17058](https://github.com/vitessio/vitess/pull/17058)
+ * [release-21.0] Delegate Column Availability Checks to MySQL for Single-Route Queries (#17077) [#17087](https://github.com/vitessio/vitess/pull/17087)
+ * [release-21.0] bugfix: Handle CTEs with columns named in the CTE def (#17179) [#17181](https://github.com/vitessio/vitess/pull/17181)
+ * [release-21.0] Use proper keyspace when updating the query graph of a reference DML (#17226) [#17258](https://github.com/vitessio/vitess/pull/17258) 
+#### Topology
+ * [release-21.0] Close zookeeper topo connection on disconnect (#17136) [#17193](https://github.com/vitessio/vitess/pull/17193) 
+#### VReplication
+ * [release-21.0] VReplication: Qualify and SQL escape tables in created AutoIncrement VSchema definitions (#17174) [#17176](https://github.com/vitessio/vitess/pull/17176) 
+#### VTTablet
+ * [release-21.0] Fix deadlock in messager and health streamer (#17230) [#17235](https://github.com/vitessio/vitess/pull/17235)
+ * [release-21.0] Fix potential deadlock in health streamer (#17261) [#17270](https://github.com/vitessio/vitess/pull/17270)
+### CI/Build 
+#### Build/CI
+ * [release-21.0] Specify Ubuntu 24.04 for all jobs (#17278) [#17282](https://github.com/vitessio/vitess/pull/17282) 
+#### Cluster management
+ * [release-21.0] Fix flakiness in `TestListenerShutdown` (#17024) [#17189](https://github.com/vitessio/vitess/pull/17189) 
+#### General
+ * [release-21.0] Upgrade the Golang version to `go1.23.3` [#17211](https://github.com/vitessio/vitess/pull/17211)
+### Dependencies 
+#### Java
+ * [release-21.0] java package updates for grpc and protobuf and release plugins (#17100) [#17105](https://github.com/vitessio/vitess/pull/17105)
+### Documentation 
+#### Documentation
+ * [Direct PR][release-21.0] Add RPC changes segment in the summary doc [#17034](https://github.com/vitessio/vitess/pull/17034)
+### Enhancement 
+#### Online DDL
+ * [release-21.0] Improve Schema Engine's TablesWithSize80 query (#17066) [#17091](https://github.com/vitessio/vitess/pull/17091) 
+#### Query Serving
+ * [release-21.0] Fix to prevent stopping buffering prematurely (#17013) [#17205](https://github.com/vitessio/vitess/pull/17205) 
+#### VReplication
+ * [release-21.0] Binlog: Improve ZstdInMemoryDecompressorMaxSize management (#17220) [#17241](https://github.com/vitessio/vitess/pull/17241)
+### Internal Cleanup 
+#### Build/CI
+ * [release-21.0] Change the name of the vitess-tester repository (#16917) [#17030](https://github.com/vitessio/vitess/pull/17030)
+### Regression 
+#### Backup and Restore
+ * [release-21.0] Fix unreachable errors when taking a backup (#17062) [#17112](https://github.com/vitessio/vitess/pull/17112)
+### Release 
+#### General
+ * [release-21.0] Bump to `v21.0.1-SNAPSHOT` after the `v21.0.0` release [#17098](https://github.com/vitessio/vitess/pull/17098)
+### Testing 
+#### Build/CI
+ * [release-21.0] Flakes: Address flakiness in TestZkConnClosedOnDisconnect (#17194) [#17197](https://github.com/vitessio/vitess/pull/17197) 
+#### Query Serving
+ * [release-21.0] fix: flaky test on twopc transaction (#17068) [#17070](https://github.com/vitessio/vitess/pull/17070)
+

changelog/21.0/21.0.1/release_notes.md

@@ -0,0 +1,7 @@
+# Release of Vitess v21.0.1
+The entire changelog for this release can be found [here](https://github.com/vitessio/vitess/blob/main/changelog/21.0/21.0.1/changelog.md).
+
+The release includes 25 merged Pull Requests.
+
+Thanks to all our contributors: @GuptaManan100, @app/vitess-bot, @frouioui, @vitess-bot
+

changelog/21.0/README.md

@@ -1,4 +1,8 @@
 ## v21.0
+* **[21.0.1](21.0.1)**
+	* [Changelog](21.0.1/changelog.md)
+	* [Release Notes](21.0.1/release_notes.md)
+
 * **[21.0.0](21.0.0)**
 	* [Changelog](21.0.0/changelog.md)
 	* [Release Notes](21.0.0/release_notes.md)