diff --git a/internal/rootcoord/quota_center.go b/internal/rootcoord/quota_center.go
index d6c854e34c..30d6df0c8c 100644
--- a/internal/rootcoord/quota_center.go
+++ b/internal/rootcoord/quota_center.go
@@ -349,7 +349,7 @@ func (q *QuotaCenter) calculateWriteRates() error {
 	log.Debug("QuotaCenter check timeTickDelay done", zap.Float64("ttFactor", ttFactor))
 
 	memFactor := q.memoryToWaterLevel()
-	if ttFactor <= 0 {
+	if memFactor <= 0 {
 		q.forceDenyWriting(MemoryExhausted) // memory protection
 		return nil
 	}
diff --git a/internal/util/paramtable/quota_param.go b/internal/util/paramtable/quota_param.go
index 6b76301d44..754d842fc3 100644
--- a/internal/util/paramtable/quota_param.go
+++ b/internal/util/paramtable/quota_param.go
@@ -432,7 +432,7 @@ func (p *quotaConfig) initForceDenyWriting() {
 }
 
 func (p *quotaConfig) initTtProtectionEnabled() {
-	p.TtProtectionEnabled = p.Base.ParseBool("quotaAndLimits.limitWriting.ttProtection", true)
+	p.TtProtectionEnabled = p.Base.ParseBool("quotaAndLimits.limitWriting.ttProtection.enabled", true)
 }
 
 func (p *quotaConfig) initMaxTimeTickDelay() {