1、SessionHandler类中执行SUBSCRIPTION时，应该先尝试启动runningMonitor再调用embeddedServer的subscribe方法

2、embeddedServer的subscribe方法中应该首先进行checkStart操作，否则可能引起metaManager的脏启动
3、SessionHandler中增加日志

parse/src/main/java/com/alibaba/otter/canal/parse/inbound/mysql/MysqlEventParser.java

@@ -13,6 +13,7 @@ import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.exception.ExceptionUtils;
 import org.springframework.util.CollectionUtils;
 
+import com.alibaba.otter.canal.common.utils.JsonUtils;
 import com.alibaba.otter.canal.parse.CanalEventParser;
 import com.alibaba.otter.canal.parse.CanalHASwitchable;
 import com.alibaba.otter.canal.parse.driver.mysql.packets.server.FieldPacket;
@@ -410,7 +411,7 @@ public class MysqlEventParser extends AbstractMysqlEventParser implements CanalE
                     }
                 }
                 // 其余情况
-                logger.warn("prepare to find start position just last position");
+                logger.warn("prepare to find start position just last position\n {}",JsonUtils.marshalToString(logPosition));
                 return logPosition.getPostion();
             } else {
                 // 针对切换的情况，考虑回退时间