java.lang.IllegalArgumentException: Child name [/mytestapp] is not unique

Sometimes while deploying war to tomcat leads to the error.


15-Jun-2021 13:41:40.282 INFO [ajp-nio-127.0.0.1-8209-exec-10] org.apache.catalina.startup.HostConfig.undeploy Undeploying context [/mytestapp]
15-Jun-2021 13:41:40.956 INFO [ajp-nio-127.0.0.1-8209-exec-10] org.apache.catalina.startup.HostConfig.deployWAR Deploying web application archive [/opt/tomcat/webapps/mytestapp.war]
15-Jun-2021 13:41:40.963 INFO [Catalina-utility-1] org.apache.catalina.startup.HostConfig.deployWAR Deploying web application archive [/opt/tomcat/webapps/mytestapp.war]
15-Jun-2021 13:41:40.964 SEVERE [Catalina-utility-1] org.apache.catalina.startup.HostConfig.deployWAR Error deploying web application archive [/opt/tomcat/webapps/mytestapp.war]
java.lang.IllegalArgumentException: Child name [/mytestapp] is not unique
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:703)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:690)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:706)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1023)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1903)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:123)
at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:824)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:474)
at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1660)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:315)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1151)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1353)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1357)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1335)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305)
at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.base/java.lang.Thread.run(Thread.java:831)
15-Jun-2021 13:41:40.967 INFO [Catalina-utility-1] org.apache.catalina.startup.HostConfig.deployWAR Deployment of web application archive [/opt/tomcat/webapps/mytestapp.war] has finished in [4] ms
15-Jun-2021 13:41:57.889 INFO [ajp-nio-127.0.0.1-8209-exec-10] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
15-Jun-2021 13:41:57.917 INFO [ajp-nio-127.0.0.1-8209-exec-10] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
15-Jun-2021 13:41:58.869 INFO [ajp-nio-127.0.0.1-8209-exec-10] org.apache.catalina.startup.HostConfig.deployWAR Deployment of web application archive [/opt/tomcat/webapps/mytestapp.war] has finished in [17,913] ms

The important thing to see here is that 2 deployments are happening at the same time.

ajp-nio-127.0.0.1-8209-exec-10 – This process starts the deployment

Catalina-utility-1 – And then this one starts the deployment also.

It seems that tomcat deployment app has some bug.

T Tak

Hey ! I'm Tak. I'm a software developer since 2008 and been programming since I was 17 years, started with pascal. I love programming, teaching and building stuff on web.

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