All notable changes to this project are documented in this file. See also TiDB Changelog and PD Changelog.
- Improvements
- Use
zstd
to compress the Region snapshot #10005
- Use
- Bug Fixes
- Fix the issue that the coprocessor fails to properly handle the signed or unsigned integer types in the
IN
expression #10018 - Fix the issue of many empty Regions after batch ingesting SST files #10015
- Fix the potential panic that occurs when the input of
cast_string_as_time
is invalid UTF-8 bytes #9995 - Fix a bug that TiKV cannot start up after the file dictionary file is damaged #9992
- Fix the issue that the coprocessor fails to properly handle the signed or unsigned integer types in the
- Compatibility changes
- Replace the
rocksdb.auto-tuned
configuration item withrocksdb.rate-limiter-auto-tuned
- Delete the
raftstore.sync-log
configuration item. By default, written data is forcibly spilled to the disk. Before v5.0, you can explicitly disableraftstore.sync-log
. Since v5.0, the configuration value is forcibly set totrue
- Change the default value of the
gc.enable-compaction-filter
configuration item fromfalse
totrue
- Change the default value of the
rate-limiter-auto-tuned
configuration item fromfalse
totrue
- Replace the
- New features
- Support log redaction to desensitize the output log information. The configuration item
security.redact-info-log
. Its default value isfalse
, which means that desensitization is disabled. To enable desensitization for tikv-server logs, set the variable value totrue
- Support transaction async commit
- Support Raft joint consensus
- Support log redaction to desensitize the output log information. The configuration item
- Improvements
- Enable the system to automatically adjust the data compaction speed by default to balance the contention for I/O resources between background tasks and foreground reads and writes
- Enable the GC Compaction Filter feature by default to reduce GC’s consumption of CPU and I/O resources
- Improvements
- Prevent a large number of reconnections in a short period of time #9879
- Optimize the write operations in the scenarios of many tombstones #9729
- Change the default value of
leader-transfer-max-log-lag
to128
to increase the success rate of leader transfer #9605 - Bug Fixes
- Fix the issue that the
IN
expression does not properly handle unsigned/signed integers #9850 - Fix the issue that the ingest operation is not re-entrant #9779
- Fix the issue that the space is missed when converting JSON to string in TiKV coprocessor #9666
- New Features
- Improvements
- Add metrics of server information for DBaaS #9591
- Support multiple clusters in Grafana dashboards #9572
- Report RocksDB metrics to TiDB #9316
- Record the suspension time for Coprocessor tasks #9277
- Add thresholds of key counts and key size for Load Base Split #9354
- Check whether the file exists before data import #9544
- Improve Fast Tune panels #9180
- Bug Fixes
- Fix the issue that TiKV is failed to build with
PROST=1
#9604 - Fix the unmatched memory diagnostics #9589
- Fix the issue that the end key of a partial RawKV-restore range is inclusive #9583
- Fix the issue that TiKV might panic when loading the old value of a key of a rolled-back transaction during TiCDC's incremental scan #9569
- Fix the configuration glitch of old values when changefeeds with different settings connect to one Region #9565
- Fix a crash issue that occurs when running a TiKV cluster on a machine with a network interface that lacks the MAC address (introduced in v4.0.9) #9516
- Fix the issue of TiKV OOM when backing up a huge Region #9448
- Fix the issue that
region-split-check-diff
cannot be customized #9530 - Fix the issue of TiKV panic when the system time goes back #9542
- Fix the issue that TiKV is failed to build with
- Bug Fixes
- Improvements
- Add the tag to trace the source of the
split
command #8936 - Support dynamically changing the
pessimistic-txn.pipelined
configuration #9100 - Reduce the impact on performance when running Backup & Restore and TiDB Lightning #9098
- Add monitoring metrics for the ingesting SST errors #9096
- Prevent hibernation when some peers are still catching up with logs #9093
- Increase the success rate of the pipelined pessimistic locking #9086
- Change the default value of
apply-max-batch-size
andstore-max-batch-size
to1024
#9020 - Add the
max-background-flushes
configuration item #8947 - Enable the unified read pool for the storage module by default #8887
- Disable
force-consistency-checks
by default to improve performance #9029
- Add the tag to trace the source of the
- Bug Fixes
- Fix the issue that Coprocessor might return wrong results when there are more than 255 columns #9131
- Fix the issue that Region Merge might cause data loss during network partition #9108
- Fix the issue that the
ANALYZE
statement might cause panic when using thelatin1
character set #9082 - Fix the wrong results returned when converting the numeric type to the time type #9031
- Fix a bug that TiDB Lightning fails to ingest SST files to TiKV with the Importer-backend or Local-backend when Transparent Data Encryption (TDE) is enabled #8995
- Fix the invalid
advertise-status-addr
value (0.0.0.0
) #9036 - Fix the issue that an error is returned indicating that a key exists when this key is locked and deleted in a committed transaction #8930
- Fix the issue that the RocksDB cache mapping error causes data corruption #9029
- Fix a bug that Follower Read might return stale data after the leader is transferred #9240
- Improvements
- Add the Fast-Tune panel page to assist performance diagnostics #8804
- Add the
security.redact-info-log
configuration item, which redacts user data from logs #8746 - Reformat the metafile of error codes #8877
- Enable dynamically changing the
pessimistic-txn.pipelined
configuration #8853 - Enable the memory profiling features by default #8801
- Bug Fixes
- Fix the bug that the mutex conflict in encryption causes pd-worker to process heartbeats slowly #8869
- Fix the issue that the memory profile is mistakenly generated #8790
- Fix the failure to back up databases on GCS when the storage class is specified #8763
- Fix the bug that a learner cannot find a leader when the Region is restarted or newly split #8864
- Improvements
- Support the JSON log format #8382
- Bug Fixes
- Improvements
- Bug Fixes
- Fix the estimation error for a non-index column when collation is enabled #8620
- Fix the issue that Green GC might miss locks during the process of Region transfer #8460
- Fix a panic issue that occurs when TiKV runs very slowly during Raft membership change #8497
- Fix the deadlock issue that occurs between the PD client thread and other threads when calling PD sync requests #8612
- Upgrade jemalloc to v5.2.1 to address the issue of memory allocation in huge page #8463
- Fix the issue that the unified thread pool hangs for long-running queries #8427
- New Features
- Define error code for errors #8387
- Bug Fixes
- Improvements
- Bug Fixes
- Bug Fixes
- Fix a memory safety issue for the status server #8101
- Fix the issue of lost precision in JSON numeric comparison #8087
- Fix the wrong query slow log #8050
- Fix the issue that a peer cannot be removed when its store is isolated during multiple merge processes #8048
- Fix the issue that
tikv-ctl recover-mvcc
does not remove invalid pessimistic locks #8047 - Fix the issue that some Titan histogram metrics are missing #7997
- Fix the issue that TiKV returns
duplicated error
to TiCDC #7887
- New Features
- Bug Fixes
- Fix the issue that the
use-unified-pool
configuration in the startup log is incorrectly printed #7946 - Fix the issue that the tikv-ctl does not support relative path #7963
- Fix the bug that the monitoring metric of Point Selects is inaccurate #8033
- Fix the issue that a peer might not be destroyed after the network isolation disappears #8006
- Fix the issue that a
read index
request may get out-of-date commit index #8043 - Improve the reliability of backup and restore with S3 and GCS storages #7917
- Fix the issue that the
- New Features
- Add the
--advertise-status-addr
start flag to specify the status address to advertise #8046
- Add the
- Bug Fixes
- Fix the issue of backup fails with DefaultNotFound error. #7937
- Tolerate out-of-order read states from raft ready. #7930
- Handles the case when the callback is dropped by mistake when getting snapshot. #7921
- Fix the issue that
ascii_bin
andlatin1_bin
is not supported by TiKV for new collation framework. #7919 - Don't clean snapshot files when shutting down. #7927
- Encryption: fix master key not being able to rotate. #7898
- Encryption: fix snapshot apply failure caused lock CF snapshot file not being encrypted on received. #7922
- Compatibility Changes
- Move the encryption-related configuration to the security-related configuration, which means changing
[encryption]
in the TiKV configuration file to[security.encryption]
#7810
- Move the encryption-related configuration to the security-related configuration, which means changing
- New Features
- Support encryption debugging for tikv-ctl, so that tikv-ctl can be used to operate and manage the cluster when the encryption storage is enabled #7698
- Support encrypting the lock column family in snapshots #7712
- Use the heatmap in the Grafana dashboard for Raftstore latency summary to better diagnose the jitter issue #7717
- Support setting the upper limit for the size of the gRPC message #7824
- Add in Grafana dashboard the encryption-related monitoring metrics #7827
- Support Application-Layer Protocol Negotiation (ALPN) #7825
- Add more statistics about Titan #7818
- Support using the task ID provided by the client as the identifier in the unified read pool to avoid that the priority of a task is lowered by another task in the same transaction #7814
- Improve the performance of the
batch insert
request #7718
- Bug Fixes
- Fix the issue that many empty Regions are generated after restoration #7632
- Fix the panic issue of Raftstore when receiving out-of-order read index responses #7370
- Fix the issue that an invalid storage or coprocessor read pool configuration might not be rejected when the unified thread pool is enabled #7513
- Fix the panic issue of the
join
operation when the TiKV server is shut down #7713 - Fix the issue that no result is returned when searching TiKV slow logs via diagnostics API #7776
- Fix the issue that notable memory fragmentation is generated when the TiKV node is running for a long time #7556
- Fix the issue that the SQL statement fails to execute when an invalid date is stored #7268
- Fix the issue that the backup data cannot be restored from GCS #7739
- Fix the issue that KMS key ID is not validated during encryption at rest #7719
- Fix the underlying correctness issue of the Coprocessor in compilers of different architecture #7714 #7730
- Fix the
snapshot ingestion
error when encrytion is enabled #7815 - Fix the
Invalid cross-device link
error when rewriting the configuration file [#7817](tikv/tikv#7817 - Fix the issue of wrong toml format when writing the configuration file to an empty file #7817
- Fix the issue that a destroyed peer in Raftstore can still process requests #7836
- Compability Changes
- Disable the Hibernate Region feature by default #7618
- Important Bug Fixes
- New Features
- Support using the user-owned KMS key for the server-side encryption when backing up data to S3 #7630
- Enable the load-based
split region
operation #7623 - Support validating common names #7468
- Add the file lock check to avoid starting multiple TiKV instances that are bound to the same address #7447
- Support AWS KMS in encryption at rest #7465
- Bug Fixes
- Address the OpenSSL security issue: CVE-2020-1967 #7622
- Avoid protecting rollback records written by
BatchRollback
to improve performance when many write conflicts exist in optimistic transactions #7604 - Fix the issue that the needless wake-up of transactions results in useless retry and performance reduction in heavy lock-race workloads #7551
- Fix the issue that the Region might be stuck in the multi-time merging #7518
- Fix the issue that the learner is not deleted when deleting the learner #7518
- Fix the issue that follower read might cause panic in raft-rs #7408
- Fix the bug that a SQL operation might fail because of the
group by constant
error #7383 - Fix the issue that an optimistic lock might block reads if the corresponding primary lock is a pessimistic lock #7328
- Compatibility Changes
- Support the
pipelined
feature in pessimistic transactions, which improves the TPC-C performance by 20%. The risk is that the transaction commit might fail because of lock failure during the execution #6984 - Enable the
unify-read-pool
configuration item in new clusters by default and use the previous setting of this item in old clusters #7059
- Support the
- New Features
- Support the
pipelined
feature in pessimistic transactions, which improves the TPC-C performance by 20%. The risk is that the transaction commit might fail because of lock failure during the execution #6984 - Support TLS in the HTTP port #5393
- Enable the
unify-read-pool
configuration item in new clusters by default and use the previous setting of this item in old clusters #7059
- Support the
- Bug Fixes
- Fix the possible panic caused by transferring the leader when the Follower Read feature is enabled #7101
- New Features
- Support the configuration of persistent dynamic update #6684
- Bugfixes
- Compatibility Changes
- New Features
- Bugfixes
- Upgrade the RocksDB version to 6.4.6
- Fix the issue that the system cannot perform the compaction task normally when the disk space is used up by automatically creating a 2GB empty file when TiKV is started #6321
- Support quick backup and restoration
- Support reading data from Follower replicas
- Improve the performance of TiDB reading data through index #5682
- Fix the issue that the
CAST
function behaves inconsistently in TiKV and in TiDB
-
backup
- Change the name of the backup file from
start_key
to the hash value ofstart_key
to reduce the file name's length for easy reading (tikv/tikv#6198) - Disable RocksDB's
force_consistency_checks
check to avoid false positives in the consistency check #6249 - Add the incremental backup feature #6286
- Change the name of the backup file from
-
sst_importer
- Fix the issue that the SST file does not have MVCC properties during restoring #6378
- Add the monitoring items such as
tikv_import_download_duration
,tikv_import_download_bytes
,tikv_import_ingest_duration
,tikv_import_ingest_bytes
, andtikv_import_error_counter
to observe the overheads of downloading and ingesting SST files #6404
-
raftstore
- Fix the issue of Follower Read that the follower reads stale data when the leader changes, thus breaking transaction isolation #6343
- Fix the issue that an error is returned indicating that a key exists when this key is locked and deleted in a committed transaction #8931
- Add the
end_point_slow_log_threshold
configuration item #9145
- Fix the bug that TiKV panics when parsing responses with missing reason phrases #8540
- Set
sync-log
totrue
as an nonadjustable value #8636
- Change gc failure log to warning #8444
- Fix a bug that might read stale data during region merging #8111
- Fix memory leak during scheduling #8355
- Add the
hibernate-timeout
configuration that delays region hibernation to improve rolling update performance #8207
- Fix the potential wrong result read from ingested files #8039
- Fix the issue that a peer can not be removed when its store is isolated during multiple merge processes #8005
- Avoid sending store heartbeats to PD after snapshots are received #8145
- Improve the PD client log #8091
- Fix a panic issue that Titan GC may delete an already deleted blob file #7970
- Fix the issue that clean snapshot files which were in used after restarting #7925
- Change schedule tick failure log to debug level to make logs less verbose #7904
- Make grpc message size limit configurable #7822
- Fix the issue that the memory defragmentation will not be very effective after running for a long time #7790
- Improve the performance when many conflicts and the
BatchRollback
condition exist in optimistic transactions #7605 - Fix the issue of decreased performance that occurs because the pessimistic lock
waiter
is frequently awakened when many conflicts exist in pessimistic transactions #7584
- Fix the issue that the node cannot be deleted correctly after the isolation recovery in some cases #7703
- Fix the issue of data loss during network isolation caused by the Region Merge operation #7679
- Fix the issue that learner cannot be removed correctly in some cases #7598
- Fix the issue that the scanning result of raw key-value pairs might be out of order #7597
- Fix the issue of reconnection when the batch of Raft messages is too large #7542
- Fix the issue of gRPC thread deadlock caused by the empty request #7538
- Fix the issue that the processing logic of restarting the learner is incorrect during the merge process #7457
- Fix the issue that repeated requests on the cleanup of lock might destroy the atomicity of the transaction #7388
- Fix the issue of conflict detection failure or data index inconsistency caused by inserting an existing key into a transaction and then deleting it immediately when disabling the consistency check parameter #7054
- Introduce a flow control mechanism in Raftstore to solve the problem that without flow control, it might lead to too slow tracking and cause the cluster to be stuck, and the transaction size might cause frequent reconnection of TiKV connections #7072, #7076
- Optimize the log output by removing unnecessary logs #6657
- Fix the panic that might occur when the peer is removed under high loads #6704
- Fix the issue that Hibernate Regions are not waken up in some cases #6732 #6738
- Raftstore
- Raftstore
- Speed up the configuration change to speed up the Region scattering #6421
- Transaction
- Add the
tikv_lock_manager_waiter_lifetime_duration
,tikv_lock_manager_detect_duration
, andtikv_lock_manager_detect_duration
monitoring metrics to monitorwaiter
s’ lifetime, the time cost of detecting deadlocks, and the status ofWait
table #6392 - Optimize the following configuration items to reduce transaction execution latency caused by changing Region leader or the leader of deadlock detector in extreme situations #6429
- Change the default value of
wait-for-lock-time
from3s
to1s
- Change the default value of
wake-up-delay-duration
from100ms
to20ms
- Change the default value of
- Fix the issue that the leader of the deadlock detector might be incorrect during the Region Merge process #6431
- Add the
- Coprocessor
- Raftstore
- Engine
- Fix the issue that empty data might be returned because RocksDB iterator errors are not correctly processed in extreme conditions #6326
- Transaction
- Update the default value of
tikv_alloc
fromtikv_alloc/default
tojemalloc
#6206
- Update grpc to fix a potential memory leak issue #6128
- Deadlock: only observe valid region in order to make sure the manager is in the valid region #6110
- Pessimistic Transaction: keep lock's ttl when receive a smaller ttl #6056
- rust-rocksdb: fix titan options for cf when create cf #6009
- Fix TiKV panic when aggregation expr type is not valid #6002
- Pessimistic Transaction: reduce clean up requests in lock_manager #5965
- Fix a region merge bug which may cause panic: set is_merging flag after restart in raftstore #5892
- Generate flamegraph at runtime #5961
- Support to change the config gc io limit dynamically #5957
- Limit the speed of write for GC #5735
- Engine: update rocksdb and titan #5968
- rocksdb: Fix OnFlushCompleted fired before flush result write to MANIFEST pingcap/rocksdb#130
- titan: Fix status overrided by mistake pingcap/titan#111
- Makefile: add a new rule for CI test #5938
- Add metrics for commit log duration #5881
- Pessimistic Transaction: Add support for lock wait timeout #5848
- LockManager: make has_waiter accurate #5845
- Fix wrong txn_size when acquire pessimistic lock #5740
- Fix the problem that split check is always scanning caused by updating approximate in pd-worker #5716
- Update rust-rocksdb to avoid intra_L0 compaction issue #5710
- Fix the bug which may break atomicity: product primary locks of pessimistic transactions from being collapsed #5671
- Enable rocksdb force_consistency_checks and handle background error #5662
- Fix the bug in raftstore that painic when getting value encouters an error #5643
- Fix the bug that do not return the right tso when checking lock #5634
- Reduce the overhead of region's heartbeat #5620
- Reduce message flush in raftstore #5617
- Check Lock's TTL when doing clean up #5589
- Fix the issue that the approximate keys is not correct when region is empty #5414
- Make the config support rocksdb doubly skiplist to optimize
reverse-scan
#5368 - Optimize point-get in coprocessor #5463
- Support batch-split command and empty batch command #5470
- Fix
PointGetter
performance issue when there are concurrent write #5495 - Fix the output on short version flag #5501
- Support the pessmistic transaction API: txn-heart-beat #5507
titan
GC and monitoring improvement #5517- Update
grpcio
to v0.4.5 #5523 - Support GRPC memory quota #5524
- Fix commit index is not forwarded when merge entry is empty #5526
- Fix a resource leak bug in batch grpc #5567
- Fix the issue that ReadIndex might fail to respond to requests because of duplicate context #5256
- Fix potential scheduling jitters caused by premature
PutStore
#5277 - Fix incorrect timestamps reported from Region heartbeats #5296
- Fix potential TiKV panics during region merge #5291
- Speed up leader change check for the dead lock detector #5317
- Support using
grpc env
to create deadlock clients #5346 - Add
config-check
to check whether the configuration is correct #5349 - Fix the issue that ReadIndex does not return anything when there is no leader #5351
- Exclude shared block cache from core dump #5322
- Fix the bug that TiKV panics if the Raft Log is not written in time #5160
- Fix the bug that the panic information is not written into the log file after TiKV panics #5198
- Fix the bug that the insert operation might be incorrectly performed in the pessimistic transaction #5203
- Lower the output level of some logs that require no manual intervention to INFO #5193
- Improve the accuracy of monitoring the storage engine size #5200
- Improve the accuracy of the Region size in TiKV Control #5195
- Improve the performance of the deadlock detector for pessimistic locks #5192
- Improve the performance of GC in the Titan storage engine #5197
- Add the statistics of the size of blob files in statistics information #5060
- Fix the core dump issue caused by the incorrectly cleaned memory resources when the process exits #5053
- Add all monitoring metrics related to the Titan engine #4772, #4836
- Add the number of open file handles for Titan when counting the number of open file handles to avoid the issue that no file handle is available because of inaccurate statistics of file handles #5026
- Set
blob_run_mode
to decide whether to enable the Titan engine on a specific CF #4991 - Fix the issue that the read operations cannot get the commit information of pessimistic transactions #5067
- Add the
blob-run-mode
configuration parameter to control the running mode of the Titan engine, and its value can benormal
,read-only
orfallback
#4865 Improve the performance of detecting deadlocks #5089
- Engine
- Introduce Titan, a key-value plugin that improves write performance for scenarios with value sizes greater than 1KiB, and relieves write amplification in certain degrees
- Optimize memory management to reduce memory allocation and copying for
Iterator Key Bound Option
- Support
block cache
sharing among different column families
- Server
- Support reversed
raw_scan
andraw_batch_scan
- Support batch receiving and sending Raft messages, improving TPS by 7% for write intensive scenarios
- Support getting monitoring information via HTTP
- Support Local Reader in RawKV to improve performance
- Reduce context switch overhead from
batch commands
- Support reversed
- Raftstore
- Support Multi-thread Raftstore and Multi-thread Apply to improve scalabilities, concurrency capacity, and resource usage within a single node. Performance improves by 70% under the same level of pressure
- Support checking RocksDB Level 0 files before applying snapshots to avoid write stall
- Support Hibernate Regions to optimize CPU consumption from RaftStore (Experimental)
- Remove the local reader thread
- Transaction
- Support distributed GC and concurrent lock resolving for improved GC performance
- Support the pessimistic transaction model (Experimental)
- Modify the semantics of
Insert
to allow Prewrite to succeed only when there is no Key - Remove
txn scheduler
- Add monitoring items related to
read index
andGC worker
- Coprocessor
- Refactor the computation framework to implement vector operators, computation using vector expressions, and vector aggregations to improve performance
- Support providing operator execution status for the
EXPLAIN ANALYZE
statement in TiDB - Switch to the
work-stealing
thread pool model to reduce context switch cost
- Misc
- Develop a unified log format specification with restructured log system to facilitate collection and analysis by tools
- Add performance metrics related to configuration information and key bound crossing.
- Engine
- Server
- Raftstore
- Fix the issue that local reader cache is not cleared correctly. 4778
- Fix request latency jetter when transferring leader and conf changes. 4734
- Remove invalid empty callbacks. 4682
- Clear stale reads after role change. 4810
- Synchronize all CF files for the received snapshots. 4807
- Fix missing fsync calls for snapshots. 4850
- Coprocessor
- Improve coprocessor batch executor. 4877
- Transaction
- Tikv-ctl
- Improve
bad-regions
andtombstone
subcommands. 4862
- Improve
- Misc
- Add dist_release. 4841
- Engine
- Support multiple column families sharing a block cache #4563
- Server
- Raftstore
- Support hibernate Regions to reduce the consumption of the raftstore CPU #4591
- Fix the issue that the leader does not reply to the
ReadIndex
requests for the learner #4653 - Fix the issue of transferring leader failure in some cases #4684
- Fix the possible dirty read issue in some cases #4688
- Fix the issue that a snapshot lacks data in some cases #4716
- Coprocessor
- Add more RPN functions
LogicalOr
#4691LTReal
#4602LEReal
#4602GTReal
#4602GEReal
#4602NEReal
#4602EQReal
#4602IsNull
#4720IsTrue
#4720IsFalse
#4720- Support comparison arithmetic for
Int
#4625 - Support comparison arithmetic for
Decimal
#4625 - Support comparison arithmetic for
String
#4625 - Support comparison arithmetic for
Time
#4625 - Support comparison arithmetic for
Duration
#4625 - Support comparison arithmetic for
Json
#4625 - Support plus arithmetic for
Int
#4733 - Support plus arithmetic for
Real
#4733 - Support plus arithmetic for
Decimal
#4733 - Support MOD functions for
Int
#4727 - Support MOD functions for
Real
#4727 - Support MOD functions for
Decimal
#4727 - Support minus arithmetic for
Int
#4746 - Support minus arithmetic for
Real
#4746 - Support minus arithmetic for
Decimal
#4746
- Add more RPN functions
- Engine
- Fix the issue that may cause incorrect statistics on read traffic #4436
- Fix the issue that may cause prefix extractor panic when deleting a range #4503
- Optimize memory management to reduce memory allocation and copying for
Iterator Key Bound Option
#4537 - Fix the issue that failing to consider learner log gap may in some cases cause panic #4559
- Support
block cache
sharing among differentcolumn families
#4612
- Server
- RaftStore
- Support configurable
properties index distance
#4517
- Support configurable
- Coprocessor
- Add batch index scan executor #4419
- Add vectorized evaluation framework #4322
- Add execution summary framework for batch executors #4433
- Check the maximum column when constructing the RPN expression to avoid invalid column offset that may cause evaluation panic #4481
- Add
BatchLimitExecutor
#4469 - Replace the original
futures-cpupool
withtokio-threadpool
in ReadPool to reduce context switch #4486 - Add batch aggregation framework #4533
- Add
BatchSelectionExecutor
#4562 - Add batch aggression function
AVG
#4570 - Add RPN function
LogicalAnd
#4575
- Misc
- Support
tcmalloc
as a memory allocator #4370
- Support
- Optimize the Coprocessor calculation execution framework and implement the TableScan section, with the Single TableScan performance improved by 5% ~ 30%
- Implement the definition of the
BatchRows
row and theBatchColumn
column #3660 - Implement
VectorLike
to support accessing encoded and decoded data in the same way #4242 - Define the
BatchExecutor
to interface and implement the way of converting requests toBatchExecutor
#4243 - Implement transforming the expression tree into the RPN format #4329
- Implement the
BatchTableScanExecutor
vectorization calculation operator #4351
- Implement the definition of the
- Unify the log format for easy collection and analysis by tools
- Support using the Local Reader to read in the Raw Read interface #4222
- Add metrics about configuration information #4206
- Add metrics about key exceeding bound #4255
- Add an option to control panic or return an error when encountering the key exceeding bound error #4254
- Add support for the
INSERT
operation, make prewrite succeed only when keys do not exist, and eliminateBatch Get
#4085 - Use more fair batch strategy in the Batch System #4200
- Support Raw scan in tikv-ctl #3825
- Support hibernating regions #4591
- Support distributed GC #3179
- Check RocksDB Level 0 files before applying snapshots to avoid Write Stall #3606
- Support reverse
raw_scan
andraw_batch_scan
#3724 - Support using HTTP to obtain monitoring information #3855
- Support DST better #3786
- Support receiving and sending Raft messages in batch #3913
- Introduce a new storage engine Titan #3985
- Upgrade gRPC to v1.17.2 #4023
- Support receiving the client requests and sending replies in batch #4043
- Support multi-thread Apply #4044
- Support multi-thread Raftstore #4066
- Raftstore:Fix the panic occurred when restarting TiKV and
is_merging
is given an incorrect value in the process of merging Regions and applying the Compact log #5884 - Importer:Remove the limit on the gRPC message length #5809
- Fix the incorrect result of counting keys in a Region in some cases #5415
- Add the
config-check
option in TiKV to check whether the TiKV configuration item is valid #5391 - Optimize the starting process to reduce jitters caused by restarting nodes #5277
- Optimize the resolving locking process in some cases to speed up resolving locking for transactions #5339
- Optimize the
get_txn_commit_info
process to speed up committing transactions #5062 - Simplify Raft-related logs #5425
- Resolve the issue that TiKV exits abnormally in some cases #5441
- Unify the log format #5083
- Improve the accuracy of Region's approximate size or keys in extreme cases to improve the accuracy of scheduling #5085
- Optimize processing the empty callback when processing the Raftstore message to avoid sending unnecessary message #4682
- Fix the issue that incomplete snapshots are generated in the system caused by the iterator not checking the status #4940
- Add a feature to check the validity for the
block-size
configuration #4930
- Fix the issue that Regions are not available during the leader transfer process in extreme conditions #4799
- Fix the issue that TiKV loses data when the power of the machine fails abnormally, caused by delayed data flush to the disk when receiving snapshots #4850
- Fix the issue that the learner reads an empty index when there is only one leader and one learner #4751
- Process
ScanLock
andResolveLock
in the thread pool with a high priority to reduce their impacts on commands with a normal priority #4791 - Synchronize all CF files for received snapshots #4811
- Reject transfer leader when the region recently changed config #4684
- Add priority label to coprocessor metrics #4643
- Fix the issue that read index may read stale data during transfering leader #4724
- Fix the issue that
CommitMerge
may cause TiKV unable to restart #4615 - Fix unknown logs #4730
- Fix potential quorum changes when transferring leader (tikv/raft-rs#221)
- Fix the Importer bug that some SST files fail to be imported but it still returns successful import result #4566
- Support setting a speed limit in Importer when uploading SST files to TiKV #4607
- Change Importer RocksDB SST default compression method to
lz4
to reduce CPU consumption #4624
- Fix the issue of wrong statistics of the read traffic #4441
- Fix the raftstore performance issue when checking to decide whether to process pending snapshots when many Regions exist #4484
- Do not ingest files when the number of level 0 SST files exceeds
level_zero_slowdown_writes_trigger/2
#4464
- Fix the
StoreNotMatch
issue caused by decoding protobuf error in some cases #4303 - Improve import speed by increasing default region-split-size to 512 MiB #4347
- Fix OOM issue by storing the intermediate SST files on disk instead of memory #4348
- Restrict memory usage by RocksDB #4350
- Fix the issue that scattering Region doesn't take effect #4352
- Fix the panic issue caused by Region merge in some cases #4235
- Fix the issue that Importer fails to import data in some cases #4223
- Fix the
KeyNotInRegion
error in some cases #4125 - Add the detailed
StoreNotMatch
error message #3885
- Fix the abnormal result issue of the event listener in some cases #4126
- Fix the duplicate write issue when closing TiKV #4146
- Support obtaining the monitoring information using the HTTP method #3855
- Fix the NULL issue of data_format #4075
- Add verifying the range for scan requests #4124
- Support the configuration format in the unit of
DAY
(d
) and fix the configuration compatibility issue #3931 - Fix the possible panic issue caused by
Approximate Size Split
#3942 - Fix two issues about Region merge #3822, #3873
- Avoid transferring the leader to a newly created peer, to optimize the possible delay #3878
- Coprocessor
- Add more built-in functions
- Add Coprocessor
ReadPool
to improve the concurrency in processing the requests - Fix the time function parsing issue and the time zone related issues
- Optimize the memory usage for pushdown aggregation computing
- Transaction
- Optimize the read logic and memory usage of MVCC to improve the performance of the scan operation and the performance of full table scan is 1 time better than that in TiDB 2.0
- Fold the continuous Rollback records to ensure the read performance
- Add the
UnsafeDestroyRange
API to support to collecting space for the dropping table/index - Separate the GC module to reduce the impact on write
- Add the
upper bound
support in thekv_scan
command
- Raftstore
- Improve the snapshot writing process to avoid RocksDB stall
- Add the
LocalReader
thread to process read requests and reduce the delay for read requests - Support
BatchSplit
to avoid large Region brought by large amounts of write - Support
Region Split
according to statistics to reduce the I/O overhead - Support
Region Split
according to the number of keys to improve the concurrency of index scan - Improve the Raft message process to avoid unnecessary delay brought by
Region Split
- Enable the
PreVote
feature by default to reduce the impact of network isolation on services
- Storage Engine
- Fix the
CompactFiles
bug in RocksDB and reduce the impact on importing data using Lightning - Upgrade RocksDB to v5.15 to fix the possible issue of snapshot file corruption
- Improve
IngestExternalFile
to avoid the issue that flush could block write
- Fix the
- tikv-ctl
- Add the
ldb
command to diagnose RocksDB related issues - The
compact
command supports specifying whether to compact data in the bottommost level
- Add the
- Tools
- Fast full import of large amounts of data: TiDB-Lightning
- Support new TiDB-Binlog
- Improve the error message of
WriteConflict
#3750 - Add the panic mark file #3746
- Downgrade grpcio to avoid the segment fault issue caused by the new version of gRPC #3650
- Add the upper limit to the
kv_scan
interface #3749
- Optimize the RocksDB Write stall issue caused by applying snapshots #3606
- Add raftstore
tick
metrics #3657 - Upgrade RocksDB and fix the Write block issue and that the source file might be damaged by the Write operation when performing
IngestExternalFile
#3661 - Upgrade grpcio and fix the issue that “too many pings” is wrongly reported #3650
- Optimize the concurrency for coprocessor requests #3515
- Add the support for Log functions #3603
- Add the support for the
sha1
function #3612 - Add the support for the
truncate_int
function #3532 - Add the support for the
year
function #3622 - Add the support for the
truncate_real
function #3633
- Fix the reporting error behavior related to time functions #3487, #3615
- Fix the issue that the time parsed from string is inconsistent with that in TiDB #3589
- Support splitting Regions based on statistics estimation to reduce the I/O cost #3511
- Reduce clone in the transaction scheduler #3530
- Add the pushdown support for a large number of built-in functions
- Add the
leader-transfer-max-log-lag
configuration to fix the failure issue of leader scheduling in specific scenarios #3507 - Add the
max-open-engines
configuration to limit the number of engines opened bytikv-importer
simultaneously #3496 - Limit the cleanup speed of garbage data to reduce the impact on
snapshot apply
#3547 - Broadcast the commit message for crucial Raft messages to avoid unnecessary delay #3592
- Fix the leader election issue caused by discarding the
PreVote
message of the newly split Region #3557 - Fix follower related statistics after merging Regions #3573
- Fix the issue that the local reader uses obsolete Region information #3565
- Support UnsafeDestroyRange API to speedup garbage data cleaning after table/index has been truncated/dropped #3560
- Support
batch split
to avoid too large Regions caused by the Write operation on hot Regions - Support splitting Regions based on the number of rows to improve the index scan efficiency
- Use
LocalReader
to separate the Read operation from the raftstore thread to lower the Read latency - Refactor the MVCC framework, optimize the memory usage and improve the scan Read performance
- Support splitting Regions based on statistics estimation to reduce the I/O usage
- Optimize the issue that the Read performance is affected by continuous Write operations on the rollback record
- Reduce the memory usage of pushdown aggregation computing
- Add the pushdown support for a large number of built-in functions and better charset support
- Optimize the GC workflow, improve the GC speed and decrease the impact of GC on the system
- Enable
prevote
to speed up service recovery when the network is abnormal - Add the related configuration items of RocksDB log files
- Adjust the default configuration of
scheduler_latch
- Support setting whether to compact the data in the bottom layer of RocksDB when using tikv-ctl to compact data manually
- Add the check for environment variables when starting TiKV
- Support dynamically configuring the
dynamic_level_bytes
parameter based on the existing data - Support customizing the log format
- Integrate tikv-fail in tikv-ctl
- Add I/O metrics of threads
- Fix decimal related issues
- Fix the issue that
gRPC max_send_message_len
is set mistakenly - Fix the issue caused by misconfiguration of
region_size
- Upgrade Rust to the
nightly-2018-06-14
version - Provide a
Raft PreVote
configuration to avoid leader reelection generated when network recovers after network isolation - Add a metric to display the number of files and
ingest
related information in each layer of RocksDB - Print
key
with too many versions when GC works
- Use
static metric
to optimize multi-label metric performance (YCSBraw get
is improved by 3%) - Remove
box
in multiple modules and use patterns to improve the operating performance (YCSBraw get
is improved by 3%) - Use
asynchronous log
to improve the performance of writing logs - Add a metric to collect the thread status
- Decease memory copy times by decreasing
box
used in the application to improve the performance
- Fix two issues about Region merge #4003 and #4004
- Avoid transferring the leader to a newly created peer, to optimize the possible delay #3929
- Fix redundant Region heartbeats #3930
- Add the end-key limit to the kv_scan interface #3749
- Abandon the max-tasks-xxx configuration and add max-tasks-per-worker-xxx #3093
- Fix the CompactFiles issue in RocksDB #3789
- Fix the issue that the memory consumed by Raftstore EntryCache keeps increasing when a node goes down 3529
- Enable dynamic-level-bytes by default to reduce space amplification
- Update Region's approximate size and approximate keys count after Region merge
- Enlarge scheduler’s default slots to reduce false conflicts
- Reduce continuous records of rollback transactions, to improve the Read
- performance when conflicts are extremely severe
- Limit the size and number of RocksDB log files, to reduce unnecessary
- disk usage in long-running condition
- Fix the crash issue when converting the data type from string to decimal
- Fix the potential overflow issue in decimal operations
- Fix the dirty read issue that might occur in the process of merge
- Add the RocksDB
PerfContext
interface for debugging - Add the
region-properties
command fortikv-ctl
- Make GC record the log when GC encounters many versions of data
- Remove the
import-mode
parameter
- Fix the issue that
reverse-seek
is slow when many RocksDB tombstones exist - Fix the crash issue caused by
do_sub
- Correct wrong peer meta for learners
- Report an error instead of getting a result if divisor/dividend is 0 in do_div_mod
- Support configuring more gRPC related parameters
- Support configuring the timeout range of leader election
- Fix the issue that the Raft log is not printed
- Fix the issue that obsolete learner is not deleted
- Fix the issue that the snapshot intermediate file is mistakenly deleted
- Reduced number of
thread_yield
calls - Fix the issue that
SELECT FOR UPDATE
prevents others from reading
- More verbose logs for slow query
- Speed up delete range
- Fix the bug that raftstore is accidentally blocked when generating the snapshot
- Fix the issue that Learner cannot be successfully elected in special conditions
- Fix the issue that split might cause dirty read in extreme conditions
- Correct the default value of the read thread pool configuration
- Protect critical configuration from incorrect modification
- Support
Region Merge
[experimental] - Add the
Raw DeleteRange
API - Add the
GetMetric
API - Add
Raw Batch Put
,Raw Batch Get
,Raw Batch Delete
andRaw Batch Scan
- Add Column Family options for the RawKV API and support executing operation on a specific Column Family
- Support Streaming and Streaming Aggregation in Coprocessor
- Support configuring the request timeout of Coprocessor
- Carry timestamps with Region heartbeats
- Support modifying some RocksDB parameters online, such as
block-cache-size
- Support configuring the behavior of Coprocessor when it encounters some warnings or errors
- Support starting in the importing data mode to reduce write amplification during the data importing process
- Support manually splitting Region in halves
- Improve the data recovery tool
tikv-ctl
- Return more statistics in Coprocessor to guide the behavior of TiDB
- Support the
ImportSST
API to import SST files [experimental] - Add the TiKV Importer binary to integrate with TiDB Lightning to import data quickly [experimental]
- Optimize read performance using
ReadPool
and increase theraw_get/get/batch_get
by 30% - Improve metrics performance
- Inform PD immediately once the Raft snapshot process is completed to speed up balancing
- Solve performance jitter caused by RocksDB flushing
- Optimize the space reclaiming mechanism after deleting data
- Speed up garbage cleaning while starting the server
- Reduce the I/O overhead during replica migration using
DeleteFilesInRanges
- Fix the issue that gRPC call does not returned when the PD leader switches
- Fix the issue that it is slow to offline nodes caused by snapshots
- Limit the temporary space usage consumed by migrating replicas
- Report the Regions that cannot elect a leader for a long time
- Update the Region size information in time according to compaction events
- Limit the size of scan lock to avoid request timeout
- Limit the memory usage when receiving snapshots to avoid OOM
- Increase the speed of CI test
- Fix the OOM issue caused by too many snapshots
- Configure
keepalive
of gRPC - Fix the OOM issue caused by an increase of the Region number
- Reduce lock contention in Worker
- Add metrics to the FuturePool
- Fix misused metrics in Coprocessor
- Support compacting Regions in
tikv-ctl
- Add raw batch put/get/delete/scan API for TiKV service
- Add ImportKV service
- Support eval error in Coprocessor
- Support dynamic adjustment of RocksDB cache size by
tikv-ctl
- Collect number of rows scanned for each range in Coprocessor
- Support treating overflow as warning in Coprocessor
- Support learner in raftstore
- Increase snap GC timeout
- Limit the memory usage during receiving snapshots, to avoid OOM in extreme conditions
- Support configuring the behavior of Coprocessor when it encounters warnings
- Support importing the data pattern in TiKV
- Support splitting Region in the middle
- Fix the issue that too many logs are output caused by leader missing when TiKV is isolated
- Use crossbeam channel in worker
- Support Region Merge
- Add the Raw DeleteRange API
- Add the GetMetric API
- Support streaming in Coprocessor
- Support modifying RocksDB parameters online
- Inform PD immediately once the Raft snapshot process is completed, to speed up balancing
- Reduce the I/O fluctuation caused by RocksDB sync files
- Optimize the space reclaiming mechanism after deleting data
- Improve the data recovery tool
tikv-ctl
- Fix the issue that it is slow to make nodes down caused by snapshot
- Increase the raw_get/get/batch_get by 30% with ReadPool
- Support configuring the request timeout of Coprocessor
- Carry time information in Region heartbeats
- Limit the space usage of snapshot files to avoid consuming too much disk space
- Record and report the Regions that cannot elect a leader for a long time
- Speed up garbage cleaning when starting the server
- Update the size information about the corresponding Region according to compaction events
- Limit the size of scan lock to avoid request timeout
- Use DeleteRange to speed up Region deletion
- Implement IngestSST API
tikv-ctl
now can send consistency-check requests to TiKV- Support dumping stats of RocksDB and malloc in
tikv-ctl
- Reclaim disk space after data have been deleted
- Protect important configuration which cannot be changed after initial configuration
- Check whether SSD is used when you start the cluster
- Fix the issue that gRPC call is not cancelled when PD leaders switch
- Optimize the read performance using ReadPool, and improve the performance by 30% for raw get
- Improve metrics and optimize the usage of metrics
- Traverse locks using offset + limit to avoid potential GC problems
- Support resolving locks in batches to improve GC speed
- Support GC concurrency to improve GC speed
- Update the Region size using the RocksDB compaction listener for more accurate PD scheduling
- Delete the outdated data in batches using DeleteFilesInRanges, to make TiKV start faster
- Configure the Raft snapshot max size to avoid the retained files taking up too much space
- Support more recovery operations in tikv-ctl
- Optimize the ordered flow aggregation operation
- Support Raft learner
- Support TLS
- Optimize Raft Snapshot and reduce the I/O overhead
- Optimize the RocksDB configuration to improve performance
- Optimize count (*) and query performance of unique index in Coprocessor
- Solve the reconnection issue between PD and TiKV
- Enhance the features of the data recovery tool
tikv-ctl
- Support the Delete Range feature
- Support splitting according to table in Regions
- Support setting the I/O limit caused by snapshot
- Improve the flow control mechanism
- Use DeleteFilesInRanges to clear stale data and improve the TiKV starting speed
- Sync the metadata of the received Snapshot compulsorily to ensure its safety
- Use Decimal in Coprocessor sum
- Support key-only option in Table Scan executor
- Support the remote mode in tikv-ctl
- Fix the loss of scheduling command from PD
- Fix the format compatibility issue of tikv-ctl proto
- Add timeout in Push metric
- Fix the issue that it is slow to get the CPU ID using the get_cpuid function.
- Support the dynamic-level-bytes parameter to improve the space collection situation.
- Fix a possible performance issue when a snapshot is applied
- Fix the performance issue for reverse scan after removing a lot of data
- Fix the wrong encoded result for the Decimal type under special circumstances
- Support splitting table to ensure one region does not contain data from multiple tables.
- Limit the length of a key to be no more than 4 KB.
- More accurate read traffic statistics.
- Implement deep protection on the coprocessor stack.
- Fix the LIKE behavior and the do_div_mod bug.
- Support flow control with write bytes.
- Reduce Raft allocation.
- Increase coprocessor stack size to 10MB.
- Remove the useless log from coprocessor.
- Coprocessor now supports more pushdown functions
- Support pushing down the sampling operation
- Support manually triggering data compact to collect space quickly
- Improve the performance and stability
- Add a Debug API for debugging