Running Tomcat 9 with SpringBoot-App as a service with Ubuntu 18.04

Question

actually I'm not able to run a Tomcat9-WebApp properly. I'd be thankful for any help pointing me in the right direction.

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Setup:

OS : Ubuntu 18.04

App-Server : Tomcat 9.0.12 (also tested with 8.5.34)

Web-App : SpringBoot 1.5.7

JDK : 1.8.0_181

Script-Command for the startup : $CATALINA_HOME/bin/startup.sh

setenv.sh :

    JRE_HOME=path/to/jdk
    CATALINA_PID="$CATALINA_BASE/tomcat.pid"
    LOGGING_CONFIG="-Dlog4j.configurationFile=$CATALINA_BASE/conf/log4j2.xml"
    LOGGING_MANAGER="-Djava.util.logging.manager=org.apache.logging.log4j.jul.LogManager"

export CLASSPATH=$CLASSPATH:$CATALINA_HOME/lib/log4j-jul-2.11.1.jar:$CATALINA_HOME/lib/log4j-core-2.11.1.jar:$CATALINA_HOME/lib/log4j-api-2.11.1.jar:$CATALINA_HOME/lib/log4j-slf4j-impl-2.11.1.jar

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If I'm running the script as a root-user it works properly and the tomcat is fully functional.

But if I'm running the same script as a service it hangs during deployment of the WAR. CPU-usage raises constantly to 100%

systemctl start tomcat

Trace-Logs make me thinking, Tomcat is scanning each directory of the filesystem for Configuration-classes (eg: /sys/devices/pci0000:00/0000:00:18.6/subsystem/)

oacsContextConfig: Scanning directory for class files with annotations [/sys/devices/pci0000:00/0000:00:18.6/subsystem ....

The Logfiles itselfs are bigger than 200MB. The upper line is just a sample.

As said before, any help would be greatly appreciated.

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@Edit

Progress: I reseted the tomcat-logging to default. As soon as this is done. Everything works fine.

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Best wishes

Mike

Answer 1

Finally I got it working:

The issue depends on the export CLASSPATH-Command:

I don't know why, but there must not be the extension of the CLASSPATH.

Solution: Replace

export CLASSPATH=$CLASSPATH:$CATALINA_HOME/lib/log4j-jul-2.11.1.jar:$CATALINA_HOME/lib/log4j-core-2.11.1.jar:$CATALINA_HOME/lib/log4j-api-2.11.1.jar:$CATALINA_HOME/lib/log4j-slf4j-impl-2.11.1.jar

with

export CLASSPATH=$CATALINA_HOME/lib/log4j-jul-2.11.1.jar:$CATALINA_HOME/lib/log4j-core-2.11.1.jar:$CATALINA_HOME/lib/log4j-api-2.11.1.jar:$CATALINA_HOME/lib/log4j-slf4j-impl-2.11.1.jar

and the service is starting properly.

If anyone could give an explanation to this behavior. Me and I'll bet others too would love get deeper into this.

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@Edit

Well I have a possible explanation for this behavior. As $CLASSPATH is not defined during startup the result is possible "". So the starting of this line seems to be " : /another/path..." It could interepreted like " /: /another/path...". The result is, that "/" is member of the classpath. That could force spring to scan the whole filesystem.

Important: This is only a guess and it is not verified.