AntiResourceLocking on Tomcat 8

Question

We're running Tomcat8 on Windows and redeploying applications sometimes fails due to Windows locking jars of properties.

I found this documentation saying that you have to add the AntiResourceLocking-attribute to a Context-element: Apache Tomcat 8 Configuration Reference

All our servers are built using scripts so doing this in the server.xml should not be a problem (if it works?):

<Engine name="Catalina" defaultHost="localhost">
  <Host name="localhost" appBase="webapps" unpackWARs="true" autoDeploy="true">
    <Context antiResourceLocking="true"></Context>
  </Host>
</Engine>

When the server restarts Tomcat prints the following errors and we have no real clue as to what is wrong:

Failed to initialize component     [StandardEngine[Catalina].StandardHost[localhost].StandardContext[null]]

Caused by: org.apache.catalina.LifecycleException: Failed to initialize component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[null]]

Caused by: java.lang.NullPointerException
at org.apache.catalina.core.StandardContext.getObjectKeyPropertiesNameOnly(StandardContext.java:6233)

Has anyone done this before? Am I missing something?

Answer 1

What you are missing is the difference between conf/server.xml and conf/context.xml.

When you add a <Context .../> element to conf/server.xml you are defining an individual context (web application). This is equivalent to defining a <Context .../> element in CATALINA_BASE/conf/<engine-name>/<host-name>/<context-name>.xml or in a /META-INF/context.xml file packaged as part of the web application.

The <Context .../> element in conf/context.xml defines defaults for all contexts (web applications).

The single Context element you have adding in conf/server.xml is failing because you haven't specified a path.

If you really want to enable anti-resource locking for all web applications then you need to add antiResourceLocking="true" as an attribute to the <Context .../> element in CATALINA_BASE/conf/context.xml.

As an aside, this option is only a work-around for resource leaks in your web application. You might want to consider taking the time to fix those resource leaks.

Answer 2

Visit http://tomcat.apache.org/tomcat-8.0-doc/config/context.html for recommended way.

You can define context.xml in META-INF/context.xml in you WAR or you can define conf/Catalina/localhost WAR_NAME.xml

• To configure antiResourceLocking in xml add following tag in context.xml

  <Context antiResourceLocking="true"></Context>