APPARENT DEADLOCK Creating emergency threads for unassigned pending tasks

项目场景：

在迁移CDH集群的元数据库后，重新启动集群，发现启动失败。

APPARENT DEADLOCK!!! Creating emergency threads for unassigned pending tasks!

---

问题描述

在启动cloudera-scm-server 时，日志如下

2022-08-25 17:24:22,222 INFO main:com.cloudera.server.cmf.Main: ================================================================================
2022-08-25 17:24:22,230 INFO main:com.cloudera.server.cmf.Main: Starting SCM Server. JVM Args: [-Dlog4j.configuration=file:/etc/cloudera-scm-server/log4j.properties, -Dfile.encoding=UTF-8, -Dcmf.root.logger=INFO,LOGFILE, -Dcmf.log.dir=/var/log/cloudera-scm-server, -Dcmf.log.file=cloudera-scm-server.log, -Dcmf.jetty.threshhold=WARN, -Dcmf.schema.dir=/opt/cloudera/cm/schema, -Djava.awt.headless=true, -Djava.net.preferIPv4Stack=true, -Dpython.home=/opt/cloudera/cm/python, -XX:+UseConcMarkSweepGC, -XX:+UseParNewGC, -XX:+HeapDumpOnOutOfMemoryError, -Xmx2G, -XX:MaxPermSize=256m, -XX:+HeapDumpOnOutOfMemoryError, -XX:HeapDumpPath=/tmp, -XX:OnOutOfMemoryError=kill -9 %p], Args: [], Version: 6.2.1 (#1426065 built by jenkins on 20190911-0956 git: 94625ae139b266e8cdad073d744766545f7f0472)
2022-08-25 17:24:22,373 INFO main:org.springframework.context.support.ClassPathXmlApplicationContext: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@11758f2a: startup date [Thu Aug 25 17:24:22 CST 2022]; root of context hierarchy
2022-08-25 17:24:22,432 INFO main:org.springframework.beans.factory.xml.XmlBeanDefinitionReader: Loading XML bean definitions from class path resource [webapp/WEB-INF/spring/beanRefFactory.xml]
2022-08-25 17:24:22,808 INFO main:org.springframework.context.support.GenericApplicationContext: Refreshing org.springframework.context.support.GenericApplicationContext@671a5887: startup date [Thu Aug 25 17:24:22 CST 2022]; root of context hierarchy
2022-08-25 17:24:22,880 INFO main:com.cloudera.enterprise.CommonMain: Reading database properties from /etc/cloudera-scm-server/db.properties
2022-08-25 17:24:22