TiDB 5.1.4 Release Notes
Release Date: February 22, 2022
TiDB version: 5.1.4
Compatibility changes
TiDB
- Change the default value of the system variable
tidb_analyze_version
from2
to1
#31748 - Since v5.1.4, if TiKV is configured with
storage.enable-ttl = true
, the requests from TiDB are rejected, because the TTL feature of TiKV only supports the RawKV mode #27303
- Change the default value of the system variable
Tools
TiCDC
- Set the default value of
max-message-bytes
to 10M #4041
- Set the default value of
Feature enhancements
TiDB
TiKV
PD
- Speed up the exit process of schedulers #4146
TiFlash
- Support pushing down
ADDDATE()
andDATE_ADD()
to TiFlash - Support pushing down
INET6_ATON()
andINET6_NTOA()
to TiFlash - Support pushing down
INET_ATON()
andINET_NTOA()
to TiFlash - Increase the max supported depth of an expression or a plan tree in a DAG request from
100
to200
- Support pushing down
Tools
TiCDC
- Add the exponential backoff mechanism for restarting a changefeed. #3329
- Reduce the replication latency when replicating many tables #3900
- Add metrics for observing the remaining time of incremental scan #2985
- Reduce the count of "EventFeed retry rate limited" logs #4006
- Add more Prometheus and Grafana monitoring metrics and alerts, including
no owner alert
,mounter row
,table sink total row
, andbuffer sink total row
#4054 #1606 - Optimize rate limiting control on TiKV reloads to reduce gPRC congestion during changefeed initialization #3110
- Reduce the time for the KV client to recover when a TiKV store is down #3191
Bug fixes
TiDB
- Fix a memory leak bug that occurs when the system variable
tidb_analyze_version
is set to2
#32499 - Fix the issue that the
MaxDays
andMaxBackups
configurations do not take effect for the slow log #25716 - Fix the issue that executing the
INSERT ... SELECT ... ON DUPLICATE KEY UPDATE
statement gets panic #28078 - Fix the wrong result that might occur when performing
JOIN
onENUM
type columns #27831 - Fix the issue that INDEX HASH JOIN returns the
send on closed channel
error #31129 - Fix the issue that using the
BatchCommands
API might block sending TiDB requests to TiKV in some rare cases #32500 - Fix the issue of potential data index inconsistency in optimistic transaction mode #30410
- Fix the issue that window functions might return different results when using a transaction or not #29947
- Fix the issue that the length information is wrong when casting
Decimal
toString
#29417 - Fix the issue that the
GREATEST
function returns incorrect result that occurs when setting thetidb_enable_vectorized_expression
vectorized expression tooff
#29434 - Fix the issue that the optimizer might cache invalid plans for
join
in some cases #28087 - Fix wrong results of the
microsecond
andhour
functions in vectorized expressions #29244 #28643 - Fix the TiDB panic when executing the
ALTER TABLE.. ADD INDEX
statement in some cases #27687 - Fix a bug that the availability detection of MPP node does not work in some corner cases #3118
- Fix the
DATA RACE
issue when assigningMPP task ID
#27952 - Fix the
INDEX OUT OF RANGE
error for a MPP query after deleting an emptydual table
#28250 - Fix the issue of false positive error log
invalid cop task execution summaries length
for MPP queries #1791 - Fix the issue that SET GLOBAL tidb_skip_isolation_level_check=1 doesn't affect new session settings #27897
- Fix a memory leak bug that occurs when the system variable
TiKV
- Fix a bug that TiKV cannot delete a range of data (
unsafe_destroy_range
cannot be executed) when the GC worker is busy #11903 - Fix the issue that destroying a peer might cause high latency #10210
- Fix a bug that the
any_value
function returns a wrong result when regions are empty #11735 - Fix the issue that deleting an uninitialized replica might cause an old replica to be recreated #10533
- Fix the metadata corruption issue when
Prepare Merge
is triggered after a new election is finished but the isolated peer is not informed #11526 - Fix the deadlock issue that happens occasionally when coroutines run too fast #11549
- Fix the potential deadlock and memory leak issues when profiling flame graphs #11108
- Fix the rare data inconsistency issue when retrying a prewrite request in pessimistic transactions #11187
- Fix a bug that the configuration
resource-metering.enabled
does not work #11235 - Fix the issue that some coroutines leak in
resolved_ts
#10965 - Fix the issue of reporting false "GC can not work" alert under low write flow #9910
- Fix a bug that tikv-ctl cannot return the correct Region-related information #11393
- Fix the issue that a down TiKV node causes the resolved timestamp to lag #11351
- Fix a panic issue that occurs when Region merge, ConfChange, and Snapshot happen at the same time in extreme conditions #11475
- Fix the issue that TiKV cannot detect the memory lock when TiKV performs a reverse table scan #11440
- Fix the issue of negative sign when the decimal divide result is zero #29586
- Fix a memory leak caused by the monitoring data of statistics threads #11195
- Fix the issue of TiCDC panic that occurs when the downstream database is missing #11123
- Fix the issue that TiCDC adds scan retries frequently due to the Congest error #11082
- Fix the issue that batch messages are too large in Raft client implementation #9714
- Collapse some uncommon storage-related metrics in Grafana dashboard #11681
- Fix a bug that TiKV cannot delete a range of data (
PD
- Fix a bug that the schedule generated by the region scatterer might decrease the number of peers #4565
- Fix the issue that Region statistics are not affected by
flow-round-by-digit
#4295 - Fix slow leader election caused by stucked region syncer #3936
- Support that the evict leader scheduler can schedule regions with unhealthy peers #4093
- Fix the issue that the cold hotspot data cannot be deleted from the hotspot statistics #4390
- Fix a panic issue that occurs after the TiKV node is removed #4344
- Fix the issue that the scheduling operator cannot fail fast because the target store is down #3353
TiFlash
- Fix the issue that the
str_to_date()
function incorrectly handles leading zeros when parsing microseconds - Fix the TiFlash crash problem when the memory limit is enabled
- Fix the issue that when an input time is earlier than 1970-01-01 00:00:01 UTC, the behavior of
unix_timestamp
is inconsistent with that of TiDB or MySQL - Fix the potential data inconsistency caused by widening the primary key column when the primary key is handle
- Fix the overflow bug and the issue of reporting
Can't compare
error when comparing data in theDECIMAL
data type - Fix the unexpected error of
3rd arguments of function substringUTF8 must be constants.
- Fix the issue that TiFlash fails to start on platforms without the
nsl
library - Fix the overflow bug when casting data to the
DECIMAL
data type - Fix the issue that the
castStringAsReal
behavior is inconsistent in TiFlash and in TiDB/TiKV - Fix the issue that TiFlash might return the
EstablishMPPConnection
error after it is restarted - Fix the issue that obsolete data cannot be reclaimed after setting the number of TiFlash replicas to 0
- Fix the issue that the
CastStringAsDecimal
behavior is inconsistent in TiFlash and in TiDB/TiKV - Fix the issue that queries with the
where <string>
clause return wrong results - Fix the issue that TiFlash might panic when an MPP query is stopped
- Fix the unexpected error of
Unexpected type of column: Nullable(Nothing)
- Fix the issue that the
Tools
TiCDC
- Fix a bug that MySQL sink generates duplicated
replace
SQL statements ifbatch-replace-enable
is disabled #4501 - Fix the issue that the
cached region
monitoring metric is negative #4300 - Fix the issue that replication cannot be performed when
min.insync.replicas
is smaller thanreplication-factor
#3994 - Fix the potential panic issue that occurs when a replication task is removed #3128
- Fix the issue of potential data loss caused by inaccurate checkpoint #3545
- Fix the potential issue that the deadlock causes a replication task to get stuck #4055
- Fix the issue that special comments in DDL statements cause the replication task to stop #3755
- Fix a bug that EtcdWorker might hang the owner and processor #3750
- Fix the issue that
stopped
changefeeds resume automatically after a cluster upgrade #3473 - Fix the issue that default values cannot be replicated #3793
- Fix data inconsistency caused by TiCDC default value padding exceptions #3918 #3929
- Fix a bug that an owner gets stuck when a PD leader shuts down and transfers to a new node #3615
- Fix the TiCDC panic issue that occurs when manually cleaning the task status in etcd #2980
- Fix the issue that the service cannot be started because of a timezone issue in the RHEL release #3584
- Fix the issue of overly frequent warnings caused by MySQL sink deadlock #2706
- Fix the bug that the
enable-old-value
configuration item is not automatically set totrue
on the Canal protocol #3676 - Fix the issue that Avro sink does not support parsing JSON type columns #3624
- Fix the negative value error in the changefeed checkpoint lag #3010
- Fix the OOM issue in the container environment #1798
- Fix the TiCDC replication interruption issue when multiple TiKVs crash or during a forced restart #3288
- Fix the memory leak issue after processing DDLs #3174
- Fix the issue that changefeed does not fail fast enough when the ErrGCTTLExceeded error occurs #3111
- Fix the issue that TiCDC replication task might terminate when the upstream TiDB instance unexpectedly exits #3061
- Fix the issue that TiCDC process might panic when TiKV sends duplicate requests to the same Region #2386
- Fix the issue that Kafka may send excessively large messages by setting the default value of
max-message-bytes
to10M
#3081 - Fix the issue that TiCDC sync task might pause when an error occurs during writing a Kafka message #2978
- Fix a bug that MySQL sink generates duplicated
Backup & Restore (BR)
TiDB Binlog
- Fix the issue that DBaaS importing CSV fails with InvalidRange if CSV file size is about 256MB and
strict-format
istrue
#27763
- Fix the issue that DBaaS importing CSV fails with InvalidRange if CSV file size is about 256MB and
TiDB Lightning