卸载项目名是zaixun_yarn的项目时
tomcat实时日志会报错
[INFO] [2020-12-22 18:17:52] org.springframework.scheduling.concurrent.ExecutorConfigurationSupport.shutdown(208) | Shutting down ExecutorService 'taskScheduler'
[INFO] [2020-12-22 18:17:52] org.springframework.scheduling.concurrent.ExecutorConfigurationSupport.shutdown(208) | Shutting down ExecutorService 'applicationTaskExecutor'
[INFO] [2020-12-22 18:17:52] org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.destroy(597) | Closing JPA EntityManagerFactory for persistence unit 'primaryPersistenceUnit'
[INFO] [2020-12-22 18:17:52] com.zaxxer.hikari.HikariDataSource.close(350) | HikariPool-1 - Shutdown initiated...
[INFO] [2020-12-22 18:17:52] com.zaxxer.hikari.HikariDataSource.close(352) | HikariPool-1 - Shutdown completed.
22-Dec-2020 18:17:52.692 WARNING [http-nio-8083-exec-12] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc The web application [zaixun_yarn] registered the JDBC driver [com.mysql.cj.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
22-Dec-2020 18:17:52.693 WARNING [http-nio-8083-exec-12] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [zaixun_yarn] appears to have started a thread named [mysql-cj-abandoned-connection-cleanup] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
java.lang.Object.wait(Native Method)
java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:144)
com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:85)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)
22-Dec-2020 18:17:53.220 INFO [http-nio-8083-exec-12] org.apache.catalina.startup.HostConfig.undeploy Undeploying context [/zaixun_yarn]
22-Dec-2020 18:17:56.060 INFO [mysql-cj-abandoned-connection-cleanup] org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading Illegal access: this web application instance has been stopped already. Could not load []. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
java.lang.IllegalStateException: Illegal access: this web application instance has been stopped already. Could not load []. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading(WebappClassLoaderBase.java:1378)
at org.apache.catalina.loader.WebappClassLoaderBase.getResource(WebappClassLoaderBase.java:1030)
at com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.checkThreadContextClassLoader(AbandonedConnectionCleanupThread.java:117)
at com.mysql.cj.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:84)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
项目确实不能再访问了，可以进行重新部署，但会遇到一个问题，tomcat不会将之前部署项目时的内存释放，如果反复卸载部署的话，内存会一直增加，还会超过在catalina.sh中加的JAVA_OPTS="-Dfile.encoding=UTF-8-server -Xms512m -Xmx3072m"大小，内存占用能达到5，6G，然后偶尔在下一次部署过程中就会导致tomcat内存溢出
