Data Race found in version

TiDB
,
1

Application environment: 3 TiKV nodes, 3 PD nodes, 2 TiDB nodes in a local cluster

PoC environment

TiDB version: 6.6.0 (commit b417ad0689795a265df9cdba22c40871f50b7e55)

Reproduction method: Brought the environment up and ran a simple bank account transaction workload, using the antithesis testing platform.

Problem: 3 Data Races observed:

First DATA RACE:

WARNING: DATA RACE
Read at 0x00c001e86958 by goroutine 9152:
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).resolveLocks()
      /tidb/store/gcworker/gc_worker.go:1169 +0xb2
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).runGCJob()
      /tidb/store/gcworker/gc_worker.go:767 +0x117
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).leaderTick.func1()
      /tidb/store/gcworker/gc_worker.go:444 +0x6c

Previous write at 0x00c001e86958 by goroutine 1007:
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).checkLeader()
      /tidb/store/gcworker/gc_worker.go:1920 +0x1cb
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).tick()
      /tidb/store/gcworker/gc_worker.go:286 +0x64
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).start()
      /tidb/store/gcworker/gc_worker.go:229 +0x659
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).Start.func1()
      /tidb/store/gcworker/gc_worker.go:120 +0x64

Goroutine 9152 (running) created at:
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).leaderTick()
      /tidb/store/gcworker/gc_worker.go:443 +0xb5a
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).tick()
      /tidb/store/gcworker/gc_worker.go:293 +0x8f
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).start()
      /tidb/store/gcworker/gc_worker.go:229 +0x659
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).Start.func1()
      /tidb/store/gcworker/gc_worker.go:120 +0x64

Goroutine 1007 (running) created at:
  github.com/pingcap/tidb/store/gcworker.(*GCWorker).Start()
      /tidb/store/gcworker/gc_worker.go:120 +0x1f7
  github.com/pingcap/tidb/store/driver.(*tikvStore).StartGCWorker()
      /tidb/store/driver/tikv_driver.go:320 +0x98
  github.com/pingcap/tidb/session.BootstrapSession()
      /tidb/session/session.go:3467 +0x1aaa
  github.com/pingcap/tidb/domain.(*Domain).rebuildSysVarCache()
      /tidb/domain/sysvar_cache.go:147 +0x8d0
  github.com/pingcap/tidb/sessionctx/variable.glob..func174()
      /tidb/sessionctx/variable/sysvar.go:904 +0x5e
  github.com/pingcap/tidb/sessionctx/variable.(*SysVar).ValidateWithRelaxedValidation()
      /tidb/sessionctx/variable/variable.go:361 +0x1c7
  github.com/pingcap/tidb/domain.(*Domain).rebuildSysVarCache()
      /tidb/domain/sysvar_cache.go:146 +0x844
  github.com/pingcap/tidb/domain.(*Domain).LoadSysVarCacheLoop()
      /tidb/domain/domain.go:1448 +0xa8
  github.com/pingcap/tidb/session.BootstrapSession()
      /tidb/session/session.go:3350 +0x6d3
  github.com/pingcap/tidb/domain.(*Domain).GetSessionCache()
      /tidb/domain/sysvar_cache.go:62 +0x59
  github.com/pingcap/tidb/session.(*session).loadCommonGlobalVariablesIfNeeded()
      /tidb/session/session.go:3669 +0x104
  github.com/pingcap/tidb/session.(*session).ExecuteStmt()
      /tidb/session/session.go:2148 +0x145
  github.com/pingcap/tidb/session.(*session).ExecuteInternal()
      /tidb/session/session.go:1678 +0x31b
  github.com/pingcap/tidb/domain.(*Domain).LoadPrivilegeLoop()
      /tidb/domain/domain.go:1392 +0x130
  github.com/pingcap/tidb/session.BootstrapSession()
      /tidb/session/session.go:3343 +0x684
  main.createStoreAndDomain()
      /tidb/tidb-server/main.go:351 +0x304
  main.main()

Data race…

2

Did you also create a github issue for this?

3

I created a github issue in pingcap/tidb: Found a data race in GCWorker · Issue #42405 · pingcap/tidb · GitHub

BTW, if you are sure you found a bug, file an issue directly in Github is preferred.