TiDB 6.5.9 Release Notes
Release date: April 12, 2024
TiDB version: 6.5.9
Quick access: Quick start | Production deployment
Compatibility changes
- Add a TiKV configuration item
track-and-verify-wals-in-manifest
for RocksDB, which helps you investigate possible corruption of Write Ahead Log (WAL) #16549 @v01dstar - DR Auto-Sync supports configuring
wait-recover-timeout
, which enables you to control the waiting time for switching back to thesync-recover
status after the network recovers #6295 @disksing
Improvements
TiDB
- When
force-init-stats
is set totrue
, TiDB waits for statistics initialization to finish before providing services during TiDB startup. This setting no longer blocks the startup of HTTP servers, which enables users to continue monitoring #50854 @hawkingrei - Optimize the issue that the
ANALYZE
statement blocks the metadata lock #47475 @wjhuang2016
- When
TiKV
- Remove unnecessary async blocks to reduce memory usage #16540 @overvenus
- Avoid performing IO operations on snapshot files in raftstore threads to improve TiKV stability #16564 @Connor1996
- Add slow logs for peer and store messages #16600 @Connor1996
Tools
Backup & Restore (BR)
- Optimize the Recovery Point Objective (RPO) for log backup during rolling restarts. Now, the checkpoint lag of log backup tasks will be smaller during rolling restarts #15410 @YuJuncen
- Enhance the tolerance of log backup to merge operations. When encountering a reasonably long merge operation, log backup tasks are less likely to enter the error state #16554 @YuJuncen
- Support automatically abandoning log backup tasks when encountering a large checkpoint lag, to avoid prolonged blocking GC and potential cluster issues #50803 @RidRisR
- Alleviate the issue that the latency of the PITR log backup progress increases when Region leadership migration occurs #13638 @YuJuncen
- Improve the speed of merging SST files during data restore by using a more efficient algorithm #50613 @Leavrth
- Support ingesting SST files in batch during data restore #16267 @3pointer
- Remove an outdated compatibility check when using Google Cloud Storage (GCS) as the external storage #50533 @lance6716
- Print the information of the slowest Region that affects global checkpoint advancement in logs and metrics during log backups #51046 @YuJuncen
- Refactor the BR exception handling mechanism to increase tolerance for unknown errors #47656 @3pointer
Bug fixes
TiDB
- Fix the issue that dropped tables are still counted by the Grafana
Stats Healthy Distribution
panel #39349 @xuyifangreeneyes - Fix the issue that TiDB does not handle the
WHERE <column_name>
filtering condition in a SQL statement when the query of that statement involves theMemTableScan
operator #40937 @zhongzc - Fix the issue that query results might be incorrect when the
HAVING
clause in a subquery contains correlated columns #51107 @hawkingrei - Fix the issue that query results might be incorrect when you use Common Table Expressions (CTE) to access partitioned tables with missing statistics #51873 @qw4990
- Fix the issue that query execution using MPP might lead to incorrect query results when a SQL statement contains
JOIN
and theSELECT
list in the statement contains only constants #50358 @yibin87 - Fix the issue that the
AUTO_INCREMENT
attribute causes non-consecutive IDs due to unnecessary transaction conflicts when assigning auto-increment IDs #50819 @tiancaiamao - Fix the issue that the monitoring metric
tidb_statistics_auto_analyze_total
on Grafana is not displayed as an integer #51051 @hawkingrei - Fix the issue that errors might be returned during the concurrent merging of global statistics for partitioned tables #48713 @hawkingrei
- Fix the issue that getting the default value of a column returns an error if the column default value is dropped #50043 #51324 @crazycs520
- Fix the issue that the
INSERT ignore
statement cannot fill in default values when the column is write-only #40192 @YangKeao - Fix the issue that TiDB crashes when
shuffleExec
quits unexpectedly #48230 @wshwsh12 - Fix the goroutine leak issue that might occur when the
HashJoin
operator fails to spill to disk #50841 @wshwsh12 - Fix the issue that renaming tables does not take effect when committing multiple statements in a transaction #39664 @tiancaiamao
- Fix the issue that the query result is incorrect when the
IN()
predicate containsNULL
#51560 @winoros - Fix the issue that querying JSON of
BINARY
type might cause an error in some cases #51547 @YangKeao - Fix the issue that parallel
Apply
might generate incorrect results when the table has a clustered index #51372 @guo-shaoge - Fix the issue that the
init-stats
process might cause TiDB to panic and theload stats
process to quit #51581 @hawkingrei - Fix the issue that the
tidb_merge_partition_stats_concurrency
variable does not take effect whenauto analyze
is processing partitioned tables #47594 @hawkingrei - Fix the issue that after the time window for automatic statistics updates is configured, statistics might still be updated outside that time window #49552 @hawkingrei
- Fix the issue that the
approx_percentile
function might cause TiDB panic #40463 @xzhangxian1008 - Fix the issue that
BIT
type columns might cause query errors due to decode failures when they are involved in calculations of some functions #49566 #50850 #50855 @jiyfhust - Fix the goroutine leak issue that occurs when the memory usage of CTE queries exceed limits #50337 @guo-shaoge
- Fix the issue that TiDB does not listen to the corresponding port when
force-init-stats
is configured #51473 @hawkingrei - Fix the issue that
ALTER TABLE ... COMPACT TIFLASH REPLICA
might incorrectly end when the primary key type isVARCHAR
#51810 @breezewish - Fix the issue that the
tidb_gogc_tuner_threshold
system variable is not adjusted accordingly after thetidb_server_memory_limit
variable is modified #48180 @hawkingrei - Fix the
Can't find column ...
error that might occur when aggregate functions are used for group calculations #50926 @qw4990 - Fix the issue that the
REVERSE
function reports an error when processing columns of theBIT
type #50850 #50855 @jiyfhust - Fix the issue that
INSERT IGNORE
reports an error when inserting data in bulk into a table undergoing a DDL operation #50993 @YangKeao - Fix the issue that the TiDB server adds a label via the HTTP interface and returns success, but does not take effect #51427 @you06
- Fix the issue that the type returned by the
IFNULL
function is inconsistent with MySQL #51765 @YangKeao - Fix the issue that the TiDB server is marked as health before the initialization is complete #51596 @shenqidebaozi
- Fix the issue that querying the
TIDB_HOT_REGIONS
table might incorrectly returnINFORMATION_SCHEMA
tables #50810 @Defined2014 - Fix the issue that
EXCHANGE PARTITION
incorrectly processes foreign keys #51807 @YangKeao - Fix the issue that executing queries containing CTEs causes TiDB to panic #41688 @srstack
- Fix the issue that dropped tables are still counted by the Grafana
TiKV
- Fix the issue that after the process of destroying Peer is interrupted by applying snapshots, it does not resume even after applying snapshots is complete #16561 @tonyxuqqi
- Fix the issue that inactive Write Ahead Logs (WALs) in RocksDB might corrupt data #16705 @Connor1996
- Fix the issue that TiKV converts the time zone incorrectly for Brazil and Egypt #16220 @overvenus
- Fix the issue that the monitoring metric
tikv_unified_read_pool_thread_count
has no data in some cases #16629 @YuJuncen - Fix the issue that JSON integers greater than the maximum
INT64
value but less than the maximumUINT64
value are parsed asFLOAT64
by TiKV, resulting in inconsistency with TiDB #16512 @YangKeao - Fix the issue that during the execution of an optimistic transaction, if other transactions initiate the resolving lock operation on it, there is a small chance that the atomicity of the transaction might be broken if the transaction's primary key has data that was previously committed in Async Commit or 1PC mode #16620 @MyonKeminta
PD
- Fix the issue that the scaling progress is not correctly displayed #7726 @CabinfeverB
- Fix the issue that data race occurs when the
MergeLabels
function is called #7535 @lhy1024 - Fix the issue that the PD monitoring item
learner-peer-count
does not synchronize the old value after a leader switch #7728 @CabinfeverB - Fix the issue that the query result of
SHOW CONFIG
includes the deprecated configuration itemtrace-region-flow
#7917 @rleungx
TiFlash
- Fix the issue that TiFlash might panic due to unstable network connections with PD during replica migration #8323 @JaySon-Huang
- Fix the issue that TiFlash might crash due to data race in case of remote reads #8685 @solotzg
- Fix the issue that the
ENUM
column might cause TiFlash to crash during chunk encoding #8674 @yibin87 - Fix the issue that TiFlash might panic when you insert data to columns with invalid default values in non-strict
sql_mode
#8803 @Lloyd-Pottiger - Fix the issue that if Region migration, split, or merge occurs after the precision of a
TIME
column is modified, queries might fail #8601 @JaySon-Huang
Tools
Backup & Restore (BR)
- Fix the issue that too many logs are printed when a full backup fails #51572 @Leavrth
- Fix the issue that removing a log backup task after it is paused does not immediately restore the GC safepoint #52082 @3pointer
- Fix the issue that BR could not back up the
AUTO_RANDOM
ID allocation progress in a union clustered index that contains anAUTO_RANDOM
column #52255 @Leavrth - Fix the issue that stopping a log backup task causes TiDB to crash #50839 @YuJuncen
- Fix the issue that TiKV panics when a full backup fails to find a peer in some extreme cases #16394 @Leavrth
TiCDC
- Fix the issue that
snapshot lost caused by GC
is not reported in time when resuming a changefeed and thecheckpoint-ts
of the changefeed is smaller than the GC safepoint of TiDB #10463 @sdojjy - Fix the issue that data is written to a wrong CSV file due to wrong BarrierTS in scenarios where DDL statements are executed frequently #10668 @lidezhu
- Fix the issue that the Syncpoint table might be incorrectly replicated #10576 @asddongmen
- Fix the issue TiCDC panics when scheduling table replication tasks #10613 @CharlesCheung96
- Fix the issue that data race in the KV client causes TiCDC to panic #10718 @asddongmen
- Fix the issue that the file sequence number generated by the storage service might not increment correctly when using the storage sink #10352 @CharlesCheung96
- Fix the issue that TiCDC cannot access Azure and GCS properly in storage sink scenarios #10592 @CharlesCheung96
- Fix the issue that the old value part of
open-protocol
incorrectly outputs the default value according to theSTRING
type instead of its actual type #10803 @3AceShowHand - Fix the issue that a changefeed with eventual consistency enabled might fail when the object storage sink encounters a temporary failure #10710 @CharlesCheung96
- Fix the issue that
TiDB Data Migration (DM)
TiDB Lightning