*: add warn log for stale read (pingcap#30340)

Signed-off-by: yisaer <disxiaofei@163.com>
qw4990 · Dec 9, 2021 · ca901be · ca901be
1 parent dd78177
commit ca901be
Showing 1 changed file with 15 additions and 5 deletions.
diff --git a/expression/builtin_time.go b/expression/builtin_time.go
@@ -7188,11 +7188,21 @@ func CalAppropriateTime(minTime, maxTime, minSafeTime time.Time) time.Time {
 //   2. If t2 < t, we will use t2 as the result,
 //      and with it, a read request won't fail because it's bigger than the latest SafeTS.
 func calAppropriateTime(minTime, maxTime, minSafeTime time.Time) time.Time {
-	if minSafeTime.Before(minTime) {
-		return minTime
-	} else if minSafeTime.After(maxTime) {
-		return maxTime
-	}
+	if minSafeTime.Before(minTime) || minSafeTime.After(maxTime) {
+		logutil.BgLogger().Warn("calAppropriateTime",
+			zap.Time("minTime", minTime),
+			zap.Time("maxTime", maxTime),
+			zap.Time("minSafeTime", minSafeTime))
+		if minSafeTime.Before(minTime) {
+			return minTime
+		} else if minSafeTime.After(maxTime) {
+			return maxTime
+		}
+	}
+	logutil.BgLogger().Debug("calAppropriateTime",
+		zap.Time("minTime", minTime),
+		zap.Time("maxTime", maxTime),
+		zap.Time("minSafeTime", minSafeTime))
 	return minSafeTime
 }