diff --git a/apm-collector/apm-collector-storage/collector-storage-es-provider/src/main/java/org/apache/skywalking/apm/collector/storage/es/dao/irmp/InstanceReferenceHourMetricEsPersistenceDAO.java b/apm-collector/apm-collector-storage/collector-storage-es-provider/src/main/java/org/apache/skywalking/apm/collector/storage/es/dao/irmp/InstanceReferenceHourMetricEsPersistenceDAO.java
index d66886c39..898557d01 100644
--- a/apm-collector/apm-collector-storage/collector-storage-es-provider/src/main/java/org/apache/skywalking/apm/collector/storage/es/dao/irmp/InstanceReferenceHourMetricEsPersistenceDAO.java
+++ b/apm-collector/apm-collector-storage/collector-storage-es-provider/src/main/java/org/apache/skywalking/apm/collector/storage/es/dao/irmp/InstanceReferenceHourMetricEsPersistenceDAO.java
@@ -22,7 +22,6 @@ import org.apache.skywalking.apm.collector.client.elasticsearch.ElasticSearchCli
 import org.apache.skywalking.apm.collector.core.storage.TimePyramid;
 import org.apache.skywalking.apm.collector.core.util.Const;
 import org.apache.skywalking.apm.collector.storage.dao.irmp.IInstanceReferenceHourMetricPersistenceDAO;
-import org.apache.skywalking.apm.collector.storage.dao.irmp.IInstanceReferenceMinuteMetricPersistenceDAO;
 import org.apache.skywalking.apm.collector.storage.table.instance.InstanceReferenceMetric;
 import org.apache.skywalking.apm.collector.storage.table.instance.InstanceReferenceMetricTable;
 import org.elasticsearch.action.index.IndexRequestBuilder;