diff --git a/modules/services/vehicle-stat-service/src/main/java/com/lingniu/ingest/vehiclestat/jt808/Jt808MileageStreamProcessor.java b/modules/services/vehicle-stat-service/src/main/java/com/lingniu/ingest/vehiclestat/jt808/Jt808MileageStreamProcessor.java
index 482005e2..d4683a1c 100644
--- a/modules/services/vehicle-stat-service/src/main/java/com/lingniu/ingest/vehiclestat/jt808/Jt808MileageStreamProcessor.java
+++ b/modules/services/vehicle-stat-service/src/main/java/com/lingniu/ingest/vehiclestat/jt808/Jt808MileageStreamProcessor.java
@@ -21,7 +21,7 @@ public final class Jt808MileageStreamProcessor {
         this.zoneId = zoneId;
     }
 
-    public synchronized void process(VehicleEnvelope envelope) {
+    public void process(VehicleEnvelope envelope) {
         extractor.extract(envelope).ifPresent(this::processPoint);
     }
 
diff --git a/modules/services/vehicle-stat-service/src/test/java/com/lingniu/ingest/vehiclestat/jt808/Jt808MileageStreamProcessorTest.java b/modules/services/vehicle-stat-service/src/test/java/com/lingniu/ingest/vehiclestat/jt808/Jt808MileageStreamProcessorTest.java
index f9c3a5ea..fe972e7d 100644
--- a/modules/services/vehicle-stat-service/src/test/java/com/lingniu/ingest/vehiclestat/jt808/Jt808MileageStreamProcessorTest.java
+++ b/modules/services/vehicle-stat-service/src/test/java/com/lingniu/ingest/vehiclestat/jt808/Jt808MileageStreamProcessorTest.java
@@ -8,6 +8,7 @@ import com.lingniu.ingest.vehiclestat.VehicleDailyStatResult;
 import com.lingniu.ingest.vehiclestat.VehicleStatRepository;
 import org.junit.jupiter.api.Test;
 
+import java.lang.reflect.Modifier;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.ZoneId;
@@ -63,6 +64,15 @@ class Jt808MileageStreamProcessorTest {
         assertThat(repository.results).isEmpty();
     }
 
+    @Test
+    void processDoesNotSerializeAllVehicleMileageUpdatesBehindOneMonitor() throws NoSuchMethodException {
+        int modifiers = Jt808MileageStreamProcessor.class
+                .getDeclaredMethod("process", VehicleEnvelope.class)
+                .getModifiers();
+
+        assertThat(Modifier.isSynchronized(modifiers)).isFalse();
+    }
+
     private static Jt808MileageStreamProcessor processor(VehicleStatRepository repository) {
         return new Jt808MileageStreamProcessor(
                 new Jt808LocationPointExtractor(),