backup: delete TestBackupRestoreWithConcurrentWrites

This test has been flaking a ton, and we already have coverage for this in the
roachtest.

Fixes #170025

Release note: none

Author: msbutler

pkg/backup/backup_test.go

@@ -3278,107 +3278,6 @@ func TestBackupRestoreIncremental(t *testing.T) {
 	}
 }
 
-// a bg worker is intended to write to the bank table concurrent with other
-// operations (writes, backups, restores), mutating the payload on rows-maxID.
-// it notified the `wake` channel (to allow ensuring bg activity has occurred)
-// and can be informed when errors are allowable (e.g. when the bank table is
-// unavailable between a drop and restore) via the atomic "bool" allowErrors.
-func startBackgroundWrites(
-	stopper *stop.Stopper, sqlDB *gosql.DB, maxID int, wake chan<- struct{}, allowErrors *int32,
-) error {
-	rng, _ := randutil.NewTestRand()
-
-	for {
-		select {
-		case <-stopper.ShouldQuiesce():
-			return nil // All done.
-		default:
-			// Keep going.
-		}
-
-		id := rand.Intn(maxID)
-		payload := randutil.RandBytes(rng, backupRestoreRowPayloadSize)
-
-		updateFn := func() error {
-			select {
-			case <-stopper.ShouldQuiesce():
-				return nil // All done.
-			default:
-				// Keep going.
-			}
-			_, err := sqlDB.Exec(`UPDATE data.bank SET payload = $1 WHERE id = $2`, payload, id)
-			if atomic.LoadInt32(allowErrors) == 1 {
-				return nil
-			}
-			return err
-		}
-		if err := retry.ForDuration(testutils.DefaultSucceedsSoonDuration, updateFn); err != nil {
-			return err
-		}
-		select {
-		case wake <- struct{}{}:
-		default:
-		}
-	}
-}
-
-func TestBackupRestoreWithConcurrentWrites(t *testing.T) {
-	defer leaktest.AfterTest(t)()
-	defer log.Scope(t).Close(t)
-
-	const rows = 10
-	const numBackgroundTasks = multiNode
-
-	skip.UnderRace(t, "test is too slow under race")
-
-	ctx := context.Background()
-	tc, sqlDB, _, cleanupFn := backupRestoreTestSetup(t, multiNode, rows, InitManualReplication)
-	defer cleanupFn()
-
-	bgActivity := make(chan struct{})
-	// allowErrors is used as an atomic bool to tell bg workers when to allow
-	// errors, between dropping and restoring the table they are using.
-	var allowErrors int32
-	for task := 0; task < numBackgroundTasks; task++ {
-		taskNum := task
-		_ = tc.Stopper().RunAsyncTask(ctx, "bg-task", func(context.Context) {
-			conn := tc.Conns[taskNum%len(tc.Conns)]
-			// Use different sql gateways to make sure leasing is right.
-			if err := startBackgroundWrites(tc.Stopper(), conn, rows, bgActivity, &allowErrors); err != nil {
-				t.Error(err)
-			}
-		})
-	}
-
-	// Use the data.bank table as a key (id), value (balance) table with a
-	// payload.The background tasks are mutating the table concurrently while we
-	// backup and restore.
-	<-bgActivity
-
-	// Set, break, then reset the id=balance invariant -- while doing concurrent
-	// writes -- to get multiple MVCC revisions as well as txn conflicts.
-	sqlDB.Exec(t, `UPDATE data.bank SET balance = id`)
-	<-bgActivity
-	sqlDB.Exec(t, `UPDATE data.bank SET balance = -1`)
-	<-bgActivity
-	sqlDB.Exec(t, `UPDATE data.bank SET balance = id`)
-	<-bgActivity
-
-	// Backup DB while concurrent writes continue.
-	sqlDB.Exec(t, `BACKUP DATABASE data INTO $1`, localFoo)
-
-	// Drop the table and restore from backup and check our invariant.
-	atomic.StoreInt32(&allowErrors, 1)
-	sqlDB.Exec(t, `DROP TABLE data.bank`)
-	sqlDB.Exec(t, `RESTORE TABLE data.* FROM LATEST IN $1`, localFoo)
-	atomic.StoreInt32(&allowErrors, 0)
-
-	bad := sqlDB.QueryStr(t, `SELECT id, balance, payload FROM data.bank WHERE id != balance`)
-	for _, r := range bad {
-		t.Errorf("bad row ID %s = bal %s (payload: %q)", r[0], r[1], r[2])
-	}
-}
-
 func TestConcurrentBackupRestores(t *testing.T) {
 	defer leaktest.AfterTest(t)()
 	defer log.Scope(t).Close(t)