releases: add tidb 5.2.2 release notes

TOC.md

@@ -558,6 +558,7 @@
 + Release Notes
   + [All Releases](/releases/release-notes.md)
   + v5.2
+    + [5.2.2](/releases/release-5.2.2.md)  
     + [5.2.1](/releases/release-5.2.1.md)
     + [5.2.0](/releases/release-5.2.0.md)
   + v5.1

releases/release-5.2.2.md

@@ -0,0 +1,109 @@
+---
+title: TiDB 5.2.2 Release Notes
+---
+
+# TiDB 5.2.2 Release Notes
+
+Release Date: October 27, 2021
+
+TiDB version: 5.2.2
+
+## Compatibility change(s)
+
+## Feature enhancement(s)
+
+## Improvements
+
++ TiDB
+
+    - Show information about SQL statement in the debug log about coprocessor encountering lock [#27718](https://github.com/pingcap/tidb/issues/27718)
+    - Add backup and restore size for TiDB SQL backup/restore task . [#27247](https://github.com/pingcap/tidb/issues/27247)
+
++ TiKV
+
+    - Simplify the algorithm of L0 flow control [#10879](https://github.com/tikv/tikv/issues/10879)
+    - Improve raft client error log report [#10983](https://github.com/tikv/tikv/pull/10983)
+    - TiKV coprocessor slow log will only consider time spent on processing the request. [#10866](https://github.com/tikv/tikv/pull/10866)
+    - Drop log instead of blocking threads when slogger thread is overloaded and queue is filled up. [#10866](https://github.com/tikv/tikv/pull/10866)
+    - Add more write query kind. [#10507](https://github.com/tikv/tikv/issues/10507)
+
++ PD
+
+    - Add more write query kind in QPS dimension for hot region scheduler [#4028](https://github.com/tikv/pd/pull/4028)
+    - Dynamically adjust the retry limit to improve the performance of the balance region scheduler [#4046](https://github.com/tikv/pd/pull/4046)
+    - Update TiDB Dashboard to v2021.10.08.1 [#4070](https://github.com/tikv/pd/pull/4070)
+    - Support scheduling regions with unhealthy peers for the evict leader scheduler [#4132](https://github.com/tikv/pd/pull/4132)
+    - Speed up scheduler exit process when receiving the signal [#4199](https://github.com/tikv/pd/pull/4199)
+
++ Tools
+
+    + TiCDC
+
+## Bug Fixes
+
++ TiDB
+
+    - Fix the issue that plan-cache cannot be aware of changes of unsigned flags [#28254](https://github.com/pingcap/tidb/issues/28254)
+    - Fix the wrong partition pruning when some conditions are out of range  [#28233](https://github.com/pingcap/tidb/issues/28233)
+    - Fix the issue that planner may cache invalid plans for joins in some cases [#28087](https://github.com/pingcap/tidb/issues/28087)
+    - Fix wrong index hash join when hash col is enum. [#27893](https://github.com/pingcap/tidb/issues/27893)
+    - Fix a batch client bug that recycle idle connection may block sending requests in some rare cases. [#27688](https://github.com/pingcap/tidb/pull/27688)
+    - Fixed Lightning panic when it failed to perform checksum on target cluster. [#27686](https://github.com/pingcap/tidb/pull/27686)
+    - Fix the wrong result for date_add and date_sub in some cases. [#27232](https://github.com/pingcap/tidb/issues/27232)
+    - Fix wrong result of hour function in vectorized expression [#28643](https://github.com/pingcap/tidb/issues/28643)
+    - Fixed a bug where MySQL 5.1 and older clients had issues authenticating [#27855](https://github.com/pingcap/tidb/issues/27855)
+    - fix auto analyze may get triggered out of specified time. [#28698](https://github.com/pingcap/tidb/issues/28698)
+    - Fix the bug that setting any session variable will make `tidb_snapshot` unwork. [#28683](https://github.com/pingcap/tidb/pull/28683)
+    - Fixed a bug that caused BR get stuck when many missing-peer regions in cluster. [#27534](https://github.com/pingcap/tidb/issues/27534)
+    - Fix unexpected error like `tidb_cast to Int32 is not supported` when unsupported cast is pushed down to TiFlash [#23907](https://github.com/pingcap/tidb/issues/23907)
+    - Fix error message for DECIMAL overflow is just "ERROR 1690 (22003): %s value is out of range in '%s'" [#27964](https://github.com/pingcap/tidb/issues/27964)
+    - Fix bug that MPP node availability detect does not work in some corner cases [#3118](https://github.com/pingcap/tics/issues/3118)
+    - Fix data-race bug when alloc MPP task ID [#27952](https://github.com/pingcap/tidb/issues/27952)
+    - Fix index out of bound bug when empty dual table is remove for MPP query [#28250](https://github.com/pingcap/tidb/issues/28250)
+    - Avoid false positive error log about `invalid cop task execution summaries length` when running MPP query. [#28264](https://github.com/pingcap/tidb/pull/28264)
+    - Fix `can not found column in Schema column` error for mpp queries [#28149](https://github.com/pingcap/tidb/pull/28149)
+    - Fix a bug that TiDB may crash when TiFlash is shutting down. [#28096](https://github.com/pingcap/tidb/issues/28096)
+    - Support for 3DES based TLS ciphersuites was removed [#27859](https://github.com/pingcap/tidb/pull/27859)
+    - Do not check multi-ingest when store is offline. [#27826](https://github.com/pingcap/tidb/pull/27826)
+    - Fix the issue that pre-check cost too much time when import too many files for tables. [#27605](https://github.com/pingcap/tidb/issues/27605)
+    - Fix expression rewrite makes `between` infers wrong collation. [#27146](https://github.com/pingcap/tidb/issues/27146)
+    - Make `group_concat` function consider the collation [#27429](https://github.com/pingcap/tidb/issues/27429)
+    - Fix extract bug when argument is a negative duration [#27236](https://github.com/pingcap/tidb/issues/27236)
+    - Fix a bug that creates partition fail if `NO_UNSIGNED_SUBTRACTION` is set. [#26765](https://github.com/pingcap/tidb/issues/26765)
+    - Avoid expressions with side effects in column pruning and aggregation pushdown. [#27106](https://github.com/pingcap/tidb/issues/27106)
+    - Remove useless GRPC log in production.[#27239](https://github.com/pingcap/tidb/pull/27239)
+    - Limit the valid decimal length to fix precision-related issues.[#3091](https://github.com/pingcap/tics/issues/3091)
+    - Fix the wrong way to check for overflow in `plus` expression.[#26977](https://github.com/pingcap/tidb/issues/26977)
+    - Fix `data too long` error when dumping stats from the table with new collation data.[#27024](https://github.com/pingcap/tidb/issues/27024)
+    - Fix retried transactions' statements are not included in TIDB_TRX.[#28670](https://github.com/pingcap/tidb/pull/28670)
+
++ TiKV
+
+    - Fix frequent CDC incremental scan retry due to `Congest` error. [#11082](https://github.com/tikv/tikv/issues/11082)
+    - Fix channel full could break the raft connection [#11047](https://github.com/tikv/tikv/issues/11047)
+    - Fix the issue that batch messages can be too large in raft client implementation [#9714](https://github.com/tikv/tikv/issues/9714)
+    - Fix coroutine leaking in `resolved_ts`. [#10965](https://github.com/tikv/tikv/issues/10965)
+    - Fix panic in coprocessor when response size exceeds 4GiB [#9012](https://github.com/tikv/tikv/issues/9012)
+    - Fix the issue that snapshot GC missed GC snapshot files when there's one snapshot file failed to be GC-ed. [#10813](https://github.com/tikv/tikv/issues/10813)
+    - Fix an unexpected panic when exceeds deadline on processing copr requests. [#10852](https://github.com/tikv/tikv/issues/10852)
+
++ PD
+
+    - Fix the issue that PD would not fix down peers in time [#4077](https://github.com/tikv/pd/issues/4077)
+    - Fix the data race issue when setting hot region configuration [#4170](https://github.com/tikv/pd/pull/4170)
+    - Fix the issue that key manager cost too much CPU [#4071](https://github.com/tikv/pd/issues/4071)
+    - Fix the issue that PD may remove the wrong pending peer if the peer count exceeds the limit [#4045](https://github.com/tikv/pd/issues/4045)
+    - Fix the issue that scatter range scheduler cannot schedule the empty region [#4118](https://github.com/tikv/pd/pull/4118)
+    - Fix the issue that PD may not elect a new leader as soon as the leader steps down [#3936](https://github.com/tikv/pd/issues/3936)
+    - Fix the issue that PD may not elect leader as soon as leader step down [#3936](https://github.com/tikv/pd/issues/3936)
+    - `evict-leader-scheduler` supports schedule the regions with unhealthy peers. [#4132](https://github.com/tikv/pd/pull/4132)
+    - Fix the bug that PD would not fix down-peer in time. [#4077](https://github.com/tikv/pd/issues/4077)
+
++ TiFlash
+
+    - Fix the issue that TiFlash fails to start up under platform without library `nsl`
+
++ Tools
+
+    + TiCDC
+

releases/release-notes.md

@@ -7,6 +7,7 @@ aliases: ['/docs/dev/releases/release-notes/','/docs/dev/releases/rn/']
 
 ## 5.2
 
+- [5.2.2](/releases/release-5.2.2.md)
 - [5.2.1](/releases/release-5.2.1.md)
 - [5.2.0](/releases/release-5.2.0.md)