store/tikv,mysql: improve error message of GC life time

domain/schema_validator.go

@@ -17,6 +17,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/pingcap/tidb/store/tikv/oracle"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -107,7 +108,7 @@ func (s *schemaValidator) Update(leaseGrantTS uint64, oldVer, currVer int64, cha
 
 	// Renew the lease.
 	s.latestSchemaVer = currVer
-	leaseGrantTime := extractPhysicalTime(leaseGrantTS)
+	leaseGrantTime := oracle.GetTimeFromTS(leaseGrantTS)
 	leaseExpire := leaseGrantTime.Add(s.lease - time.Millisecond)
 	s.latestSchemaExpire = leaseExpire
 
@@ -187,18 +188,13 @@ func (s *schemaValidator) Check(txnTS uint64, schemaVer int64, relatedTableIDs [
 	}
 
 	// Schema unchanged, maybe success or the schema validator is unavailable.
-	t := extractPhysicalTime(txnTS)
+	t := oracle.GetTimeFromTS(txnTS)
 	if t.After(s.latestSchemaExpire) {
 		return ResultUnknown
 	}
 	return ResultSucc
 }
 
-func extractPhysicalTime(ts uint64) time.Time {
-	t := int64(ts >> 18) // 18 is for the logical time.
-	return time.Unix(t/1e3, (t%1e3)*1e6)
-}
-
 func (s *schemaValidator) enqueue(schemaVersion int64, relatedTableIDs []int64) {
 	s.deltaSchemaInfos = append(s.deltaSchemaInfos, deltaSchemaInfo{schemaVersion, relatedTableIDs})
 	if len(s.deltaSchemaInfos) > maxNumberOfDiffsToLoad {

mysql/errname.go

@@ -901,7 +901,7 @@ var MySQLErrName = map[uint16]string{
 	ErrTiKVServerBusy:     "TiKV server is busy",
 	ErrResolveLockTimeout: "Resolve lock timeout",
 	ErrRegionUnavailable:  "Region is unavailable",
-	ErrGCTooEarly:         "GC life time is shorter than transaction duration",
+	ErrGCTooEarly:         "GC life time is shorter than transaction duration, transaction starts at %v, GC safe point is %v",
 
 	ErrTxnTooLarge: "Transaction is too large",
 }

store/tikv/kv.go

@@ -165,7 +165,9 @@ func (s *tikvStore) CheckVisibility(startTime uint64) error {
 	}
 
 	if startTime < cachedSafePoint {
-		return ErrGCTooEarly
+		t1 := oracle.GetTimeFromTS(startTime)
+		t2 := oracle.GetTimeFromTS(cachedSafePoint)
+		return ErrGCTooEarly.GenByArgs(t1, t2)
 	}
 
 	return nil

store/tikv/oracle/oracle.go

@@ -53,3 +53,9 @@ func GetPhysical(t time.Time) int64 {
 func EncodeTSO(ts int64) uint64 {
 	return uint64(ts) << physicalShiftBits
 }
+
+// GetTimeFromTS extracts time.Time from a timestamp.
+func GetTimeFromTS(ts uint64) time.Time {
+	ms := ExtractPhysical(ts)
+	return time.Unix(ms/1e3, (ms%1e3)*1e6)
+}