TiDB Audit Plugin User Guide August 4, 2022 TiDB Audit Plugin User Guide Introduction The TiDB audit plugin records the TiDB server’s activities that are expected to follow auditing regulations of of your organization. For each client session, the plugin records users accessing the server (that is, username and IP address), SQL queries executed, databases and tables accessed, environment variable package, and use the audit plugin. Download the plugin You can download the plugin on TiDB Enterprise Edition Downloads. Deploy the audit plugin After downloading the plugin, you can use either TiDB

Go in TiDB 申砾@PingCAP Agenda • About Me • What is TiDB • TiDB Architecture • SQL Layer Internal • Golang in TiDB • Next Step of TiDB About Me • Shen Li (申砾) • Tech Lead of TiDB, VP of Engineering Why Go? • Productivity • Concurrency • Great for network programming • GC • Standard libraries && Tools • Good performance • Quick improvement Go in TiDB • More than 100k lines of Go code and session is hard • Account for large memory allocation • Account for memory consuming operators New in Go1.8 • Better GC • Pauses 50μs • sort.Slice Next Step of TiDB • Switch to gRPC • Document support

Go Practices in TiDB 姚维 PingCAP wink@pingcap.com Agenda ● How to build a stable database ○ Schrodinger-test platform ○ Failpoint injection ○ Goroutine-leak detection ● Optimization ○ Chunk vs interface{} errors.New("mock commit error") // } …. } https://github.com/pingcap/tidb/blob/master/store/tikv/txn.go#L223 The generated gofail code func (txn *tikvTxn) Commit(ctx context.Context) error { if vmockCommitError or: __fp_mockCommitError.BadType(vmockCommitError, "bool"); }; …. } $ gofail enable store/tikv/txn.go Why we need a new failpoint ● Generated code is not readable ● Concurrent testing will use the same

Go runtime related problems in TiDB production environment About me ● Arthur Mao(毛康力), Senior Engineer@PingCAP ● TiDB core developer (top3 contributor) ● GitBook about golang internals (@tiancaiamao) consider priority ● CPU dense workload could affect IO latency Conclusion Part II - Memory control ● Go Runtime ○ Allocated from OS (mmaped) ○ Managed Memory ■ Should the memory be returned to the OS? ○ memory footprint is abnormal ● The memory available on this node is not too much Description ● The Go Runtime thinks it does not use much memory ● The OS does not release the memory (RSS is high) Investigate

of replicas. This can guarantee strong consis- tency, and availability when a minority of replicas go down. To meet the requirements of different disaster tolerance levels, you can configure the geographic this time period. • The default storage directory for plugins is changed from "" to /data/deploy/plugin. • The DM code is migrated to the folder “dm” in TiCDC code repository. Now DM follows TiDB in version transactions’ statements are not included in TIDB_TRX #28670 – Fix the wrong default value of the plugin_dir configuration #28084 – Fix the issue that the CONVERT_TZ function returns NULL when it is given

of replicas. This can guarantee strong consis- tency, and availability when a minority of replicas go down. To meet the requirements of different disaster tolerance levels, you can configure the geographic version. 2.2.1.1 System variables Variable name Change type Description default_authentication_plugin �→ Newly added Sets the au- thentication method that the server advertises. The default value is Experimental Experimental Experimental Columnar storage (TiFlash) Y Y Y Y RocksDB engine Y Y Y Y Titan plugin Y Y Y Y Invisible indexes Y Y Y N Composite PRIMARY KEY Y Y Y Y Unique indexes Y Y Y Y Clustered

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 132 4.3.2 Go · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · majority of replicas. This guarantees strong consistency and availabil- ity when a minority of replicas go down. You can configure the geographic location and number of replicas as needed to meet different Fix the issue that TiDB server might consume a significant amount of resources when the enterprise plugin for audit logging is used #49273 @lcwangchao • Fix the issue that the optimizer incorrectly converts

of replicas. This can guarantee strong consis- tency, and availability when a minority of replicas go down. To meet the requirements of different disaster tolerance levels, you can configure the geographic Experimental Experimental Columnar storage (TiFlash) Y Y Y Y Y Y RocksDB engine Y Y Y Y Y Y Titan plugin Y Y Y Y Y Y Invisible indexes Y Y Y Y Y N Composite PRIMARY KEY Y Y Y Y Y Y Unique indexes Y Y label configuration: Since TiKV is deployed across different data centers, if the physical machines go down, the Raft Group might lose three of the default five replicas, which causes the cluster 154

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 119 4.3.2 Go · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · majority of replicas. This guarantees strong consistency and availabil- ity when a minority of replicas go down. You can configure the geographic location and number of replicas as needed to meet different graph of heap profile. This feature 38 �→ provides the same simple and easy-to-use experience as Go heap �→ profiling. 2.2.1 Feature details 2.2.1.1 Scalability • Support designating and isolating

of replicas. This can guarantee strong consis- tency, and availability when a minority of replicas go down. To meet the requirements of different disaster tolerance levels, you can configure the geographic �→ preparing �→ - �→ time �→ Newly added Controls the max- i- mum wait- ing time for the store to go on- line. 74 Configuration file Configuration Change type Description TiCDCenable �→ - �→ tls �→ Experimental Experimental Columnar storage (TiFlash) Y Y Y Y Y Y Y Y RocksDB engine Y Y Y Y Y Y Y Y Titan plugin Y Y Y Y Y Y Y Y Invisible indexes Y Y Y Y Y Y Y N 1TiDB incorrectly treats latin1 as a subset of