[Tomcat]嚴重: Context [/xxxx] startup failed due to previous errors

1 tomcat 6600啟動報錯
[root@localhost webapps]#     sh /usr/local/apache-tomcat-6.0.37_6600/bin/startup.sh 
Using CATALINA_BASE:   /usr/local/apache-tomcat-6.0.37_6600
Using CATALINA_HOME:   /usr/local/apache-tomcat-6.0.37_6600
Using CATALINA_TMPDIR: /usr/local/apache-tomcat-6.0.37_6600/temp
Using JRE_HOME:        /usr/java/jdk1.6.0_45
Using CLASSPATH:       /usr/local/apache-tomcat-6.0.37_6600/bin/bootstrap.jar
Using CATALINA_PID:    /var/tomcat/6600.pid
Existing PID file found during start.
Removing/clearing stale PID file.
看到/var/tomcat/6600.pid已經存在了，所以載入失敗。停止tomcat，然後檢查tomcat程式

2 刪除已經存在的6600.pid檔案
[root@localhost webapps]# ps -eaf|grep 6600
root     10446  4972  0 15:09 pts/2    00:00:00 grep 6600
[root@localhost webapps]# more /var/tomcat/6600.pid
10180
[root@localhost webapps]# 
[root@localhost webapps]# ll /var/tomcat/6600.pid
-rw-r--r-- 1 root root 6 05-03 15:07 /var/tomcat/6600.pid

[root@localhost webapps]# rm -rf /var/tomcat/6600.pid
[root@localhost webapps]# 

3 再重啟，還是報錯，檢視錯誤日誌如下：
tail -n 1000 /usr/local/apache-tomcat-6.0.37_6600/logs/catalina.out
2014-5-3 15:18:29 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
嚴重: The web application [/grouponAdminWeb] appears to have started a thread named [Thread-197] but has failed to stop it. This is very likely to create a memory leak.
2014-5-3 15:18:29 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
嚴重: The web application [/grouponAdminWeb] appears to have started a thread named [Thread-198] but has failed to stop it. This is very likely to create a memory leak.
......
2014-5-3 15:15:41 org.apache.catalina.startup.HostConfig deployWAR
資訊: Deploying web application archive grouponAdminWeb.war
SLF4J: This version of SLF4J requires log4j version 1.2.12 or later. See also
2014-5-3 15:15:44 org.apache.catalina.core.StandardContext start
嚴重: Error listenerStart
2014-5-3 15:15:44 org.apache.catalina.core.StandardContext start
嚴重: Context [/grouponAdminWeb] startup failed due to previous errors

從這裡可以看出grouponAdminWeb這個web應用在tomcat容器上面deploy失敗，為什麼失敗？

4 分析為什麼會deploy應用失敗？
找這個應用的設計人員，經過同事提醒，去看同一目錄的localhost.2014-05-03.log檔案
tail -n 1000 /usr/local/apache-tomcat-6.0.37_6600/logs/localhost.2014-05-03.log
有如下錯誤提示：
2014-5-3 15:15:41 org.apache.catalina.core.StandardContext listenerStart
嚴重: Exception sending context initialized event to listener instance of class org.springframework.web.util.Log4jConfigListener
java.lang.IllegalStateException: Web app root system property already set to different value: 'GrouponWeb.root' = [/usr/local/apache-tomcat-6.0.37_6600/webapps/grouponWeb/] instead of [/usr/local/apache-tomcat-6.0.37_6600/webapps/grouponAdminWeb/] - Choose unique values for the 'webAppRootKey' context-param in your web.xml files!
at org.springframework.web.util.WebUtils.setWebAppRootSystemProperty(WebUtils.java:148)
at org.springframework.web.util.Log4jWebConfigurer.initLogging(Log4jWebConfigurer.java:117)
at org.springframework.web.util.Log4jConfigListener.contextInitialized(Log4jConfigListener.java:45)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4206)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4705)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:799)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:601)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:943)
at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:778)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:504)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1317)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:324)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1065)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1057)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
at org.apache.catalina.core.StandardService.start(StandardService.java:525)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:754)
at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
2014-5-3 15:15:41 org.apache.catalina.core.ApplicationContext log
資訊: Initializing Spring root WebApplicationContext

5  看到錯誤資訊，是配置檔案有誤，去修改WEB-INF下的web.xml
vim  /usr/local/apache-tomcat-6.0.37_6600/webapps/grouponAdminWeb/WEB-INF/web.xml
將 GrouponWeb.root 的key值由GrouponWeb修改成GrouponAdminWeb，如下所示：

......

        webAppRootKey
        GrouponAdminWeb.root
   
......

之後重啟tomcat或者，重新載入GrouponAdminWeb應用，就OK了。

6 檢視最新tomcat啟動日誌如下
[root@localhost WEB-INF]# tail -n 200 /usr/local/apache-tomcat-6.0.37_6600/logs/catalina.out
資訊: Initializing Coyote HTTP/1.1 on http-6600
2014-5-3 15:18:53 org.apache.catalina.startup.Catalina load
資訊: Initialization processed in 472 ms
2014-5-3 15:18:53 org.apache.catalina.core.StandardService start
資訊: Starting service Catalina
2014-5-3 15:18:53 org.apache.catalina.core.StandardEngine start
資訊: Starting Servlet Engine: Apache Tomcat/6.0.37
2014-5-3 15:18:53 org.apache.catalina.startup.HostConfig deployDescriptor
資訊: Deploying configuration descriptor manager.xml
2014-5-3 15:18:53 org.apache.catalina.startup.HostConfig deployWAR
資訊: Deploying web application archive grouponWeb.war
SLF4J: This version of SLF4J requires log4j version 1.2.12 or later. See also
============
2014-5-3 15:18:58 org.apache.catalina.startup.HostConfig deployWAR
資訊: Deploying web application archive grouponAdminWeb.war
SLF4J: This version of SLF4J requires log4j version 1.2.12 or later. See also
============
2014-5-3 15:19:02 org.apache.catalina.startup.HostConfig deployWAR
資訊: Deploying web application archive grouponService.war
2014-5-3 15:19:04 org.apache.catalina.startup.HostConfig deployDirectory
資訊: Deploying web application directory ROOT
2014-5-3 15:19:04 org.apache.coyote.http11.Http11Protocol start
資訊: Starting Coyote HTTP/1.1 on http-6600
2014-5-3 15:19:04 org.apache.jk.common.ChannelSocket init
資訊: JK: ajp13 listening on /0.0.0.0:6609
2014-5-3 15:19:04 org.apache.jk.server.JkMain start
資訊: Jk running ID=0 time=0/13  config=null
2014-5-3 15:19:04 org.apache.catalina.startup.Catalina start
資訊: Server startup in 10955 ms


總結：tomcat容器的web應用載入報錯，除了要去看catalina.log日誌之外，還要去看localhost.2014-05-03.log日誌資訊。