centos下，tomcat7关闭后报错内存泄露，并开启多个java进程，不知怎么处理

每次发布项目的时候，tomcat执行shutdown.sh之后，都会打印以下日志，

并且会在linux中开启几个java进程，占了很多内存，找了很久的原因，都不知道怎么处理，希望大佬帮忙解答一下。

四月 02, 2019 1:48:34 下午 org.apache.coyote.AbstractProtocol pause

信息: Pausing ProtocolHandler ["http-bio-80"]

四月 02, 2019 1:48:34 下午 org.apache.coyote.AbstractProtocol pause

信息: Pausing ProtocolHandler ["ajp-bio-8009"]

四月 02, 2019 1:48:35 下午 org.apache.catalina.core.StandardService stopInternal

信息: Stopping service Catalina

四月 02, 2019 1:48:35 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads

严重: The web application [/ShiJie] appears to have started a thread named [pool-1-thread-1] but has failed to stop it. This is very likely to create a memory leak.

四月 02, 2019 1:48:35 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads

严重: The web application [/ShiJie] appears to have started a thread named [pool-2-thread-1] but has failed to stop it. This is very likely to create a memory leak.

四月 02, 2019 1:48:35 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads

严重: The web application [/ShiJie] appears to have started a thread named [I/O dispatcher 1] but has failed to stop it. This is very likely to create a memory leak.

四月 02, 2019 1:48:35 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads

严重: The web application [/ShiJie] appears to have started a thread named [I/O dispatcher 2] but has failed to stop it. This is very likely to create a memory leak.

四月 02, 2019 1:48:35 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads