title: tomcat8 IllegalArgumentException: The main resource set specified [/var/lib/tomcat8/app1/ROOT] is not valid
body: <p>I have problem deploying two application on one tomcat 8 instance. I have app1 and app2. App2 gets up as intended but app1 isn't. Here is my <code>server.xml</code>:</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;?xml version='1.0' encoding='utf-8'?&gt;
  &lt;!--
    Licensed to the Apache Software Foundation (ASF) under one or more
    contributor license agreements.  See the NOTICE file distributed with
    this work for additional information regarding copyright ownership.
    The ASF licenses this file to You under the Apache License, Version 2.0
    (the "License"); you may not use this file except in compliance with
    the License.  You may obtain a copy of the License at
  
        http://www.apache.org/licenses/LICENSE-2.0
  
    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
  --&gt;
  &lt;!-- Note:  A "Server" is not itself a "Container", so you may not
       define subcomponents such as "Valves" at this level.
       Documentation at /docs/config/server.html
   --&gt;
  &lt;Server port="8005" shutdown="SHUTDOWN"&gt;
    &lt;Listener className="org.apache.catalina.startup.VersionLoggerListener" /&gt;
    &lt;!-- Security listener. Documentation at /docs/config/listeners.html
    &lt;Listener className="org.apache.catalina.security.SecurityListener" /&gt;
    --&gt;
    &lt;!--APR library loader. Documentation at /docs/apr.html --&gt;
    &lt;!--
    &lt;Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" /&gt;
    --&gt;
    &lt;!-- Prevent memory leaks due to use of particular java/javax APIs--&gt;
    &lt;Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" /&gt;
    &lt;Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" /&gt;
    &lt;Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" /&gt;
  
    &lt;!-- Global JNDI resources
         Documentation at /docs/jndi-resources-howto.html
    --&gt;
    &lt;GlobalNamingResources&gt;
      &lt;!-- Editable user database that can also be used by
           UserDatabaseRealm to authenticate users
      --&gt;
  
      &lt;Resource name="UserDatabase" auth="Container"
                type="org.apache.catalina.UserDatabase"
                description="User database that can be updated and saved"
                factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
                pathname="conf/tomcat-users.xml" /&gt;
    &lt;/GlobalNamingResources&gt;
  
    &lt;!-- A "Service" is a collection of one or more "Connectors" that share
         a single "Container" Note:  A "Service" is not itself a "Container",
         so you may not define subcomponents such as "Valves" at this level.
         Documentation at /docs/config/service.html
     --&gt;
    &lt;Service name="app1"&gt;
  
      &lt;!--The connectors can use a shared executor, you can define one or more named thread pools--&gt;
      &lt;!--
      &lt;Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
          maxThreads="150" minSpareThreads="4"/&gt;
      --&gt;
  
  
      &lt;!-- A "Connector" represents an endpoint by which requests are received
           and responses are returned. Documentation at :
           Java HTTP Connector: /docs/config/http.html (blocking &amp; non-blocking)
           Java AJP  Connector: /docs/config/ajp.html
           APR (HTTP/AJP) Connector: /docs/apr.html
           Define a non-SSL HTTP/1.1 Connector on port 8080
      --&gt;
      &lt;Connector port="8080" protocol="HTTP/1.1"
                 connectionTimeout="20000"
                 URIEncoding="UTF-8"
                 redirectPort="8443" /&gt;
      &lt;!-- A "Connector" using the shared thread pool--&gt;
      &lt;!--
      &lt;Connector executor="tomcatThreadPool"
                 port="8080" protocol="HTTP/1.1"
                 connectionTimeout="20000"
                 redirectPort="8443" /&gt;
      --&gt;
      &lt;!-- Define a SSL HTTP/1.1 Connector on port 8443
           This connector uses the NIO implementation that requires the JSSE
           style configuration. When using the APR/native implementation, the
           OpenSSL style configuration is required as described in the APR/native
           documentation --&gt;
      &lt;!--
      &lt;Connector port="8443" protocol="org.apache.coyote.http11.Http11NioProtocol"
                 maxThreads="150" SSLEnabled="true" scheme="https" secure="true"
                 clientAuth="false" sslProtocol="TLS" /&gt;
      --&gt;
  
      &lt;!-- Define an AJP 1.3 Connector on port 8009 --&gt;
      &lt;!--
      &lt;Connector port="8009" protocol="AJP/1.3" redirectPort="8443" /&gt;
      --&gt;
  
  
      &lt;!-- An Engine represents the entry point (within Catalina) that processes
           every request.  The Engine implementation for Tomcat stand alone
           analyzes the HTTP headers included with the request, and passes them
           on to the appropriate Host (virtual host).
           Documentation at /docs/config/engine.html --&gt;
  
      &lt;!-- You should set jvmRoute to support load-balancing via AJP ie :
      &lt;Engine name="app1" defaultHost="localhost" jvmRoute="jvm1"&gt;
      --&gt;
      &lt;Engine name="app1" defaultHost="localhost"&gt;
  
        &lt;!--For clustering, please take a look at documentation at:
            /docs/cluster-howto.html  (simple how to)
            /docs/config/cluster.html (reference documentation) --&gt;
        &lt;!--
        &lt;Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/&gt;
        --&gt;
  
        &lt;!-- Use the LockOutRealm to prevent attempts to guess user passwords
             via a brute-force attack --&gt;
        &lt;Realm className="org.apache.catalina.realm.LockOutRealm"&gt;
          &lt;!-- This Realm uses the UserDatabase configured in the global JNDI
               resources under the key "UserDatabase".  Any edits
               that are performed against this UserDatabase are immediately
               available for use by the Realm.  --&gt;
          &lt;Realm className="org.apache.catalina.realm.UserDatabaseRealm"
                 resourceName="UserDatabase"/&gt;
     &lt;/Realm&gt;
  
        &lt;Host name="localhost"  appBase="app1"
              unpackWARs="true" autoDeploy="true"&gt;
  
          &lt;!-- SingleSignOn valve, share authentication between web applications
               Documentation at: /docs/config/valve.html --&gt;
          &lt;!--
          &lt;Valve className="org.apache.catalina.authenticator.SingleSignOn" /&gt;
          --&gt;
  
          &lt;!-- Access log processes all example.
               Documentation at: /docs/config/valve.html
               Note: The pattern used is equivalent to using pattern="common" --&gt;
          &lt;Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
                 prefix="localhost_access_log" suffix=".txt"
                 pattern="%h %l %u %t &amp;quot;%r&amp;quot; %s %b" /&gt;
  
        &lt;/Host&gt;
      &lt;/Engine&gt;
    &lt;/Service&gt;
  
    &lt;Service name="app2"&gt;
  
      &lt;!--The connectors can use a shared executor, you can define one or more named thread pools--&gt;
      &lt;!--
      &lt;Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
          maxThreads="150" minSpareThreads="4"/&gt;
      --&gt;
  
  
      &lt;!-- A "Connector" represents an endpoint by which requests are received
           and responses are returned. Documentation at :
           Java HTTP Connector: /docs/config/http.html (blocking &amp; non-blocking)
           Java AJP  Connector: /docs/config/ajp.html
           APR (HTTP/AJP) Connector: /docs/apr.html
           Define a non-SSL HTTP/1.1 Connector on port 8080
      --&gt;
      &lt;Connector port="8888" protocol="HTTP/1.1"
                 connectionTimeout="20000"
                 URIEncoding="UTF-8"
                 redirectPort="8443" /&gt;
     &lt;!-- A "Connector" using the shared thread pool--&gt;
      &lt;!--
      &lt;Connector executor="tomcatThreadPool"
                 port="8888" protocol="HTTP/1.1"
                 connectionTimeout="20000"
                 redirectPort="8443" /&gt;
      --&gt;
      &lt;!-- Define a SSL HTTP/1.1 Connector on port 8443
           This connector uses the NIO implementation that requires the JSSE
           style configuration. When using the APR/native implementation, the
           OpenSSL style configuration is required as described in the APR/native
           documentation --&gt;
      &lt;!--
      &lt;Connector port="8443" protocol="org.apache.coyote.http11.Http11NioProtocol"
                 maxThreads="150" SSLEnabled="true" scheme="https" secure="true"
                 clientAuth="false" sslProtocol="TLS" /&gt;
      --&gt;
  
      &lt;!-- Define an AJP 1.3 Connector on port 8009 --&gt;
      &lt;!--
      &lt;Connector port="8009" protocol="AJP/1.3" redirectPort="8443" /&gt;
      --&gt;
  
  
      &lt;!-- An Engine represents the entry point (within Catalina) that processes
           every request.  The Engine implementation for Tomcat stand alone
           analyzes the HTTP headers included with the request, and passes them
           on to the appropriate Host (virtual host).
           Documentation at /docs/config/engine.html --&gt;
  
      &lt;!-- You should set jvmRoute to support load-balancing via AJP ie :
      &lt;Engine name="app2" defaultHost="localhost" jvmRoute="jvm2"&gt;
      --&gt;
      &lt;Engine name="app2" defaultHost="localhost"&gt;
  
        &lt;!--For clustering, please take a look at documentation at:
            /docs/cluster-howto.html  (simple how to)
            /docs/config/cluster.html (reference documentation) --&gt;
        &lt;!--
        &lt;Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/&gt;
        --&gt;
  
        &lt;!-- Use the LockOutRealm to prevent attempts to guess user passwords
             via a brute-force attack --&gt;
        &lt;Realm className="org.apache.catalina.realm.LockOutRealm"&gt;
          &lt;!-- This Realm uses the UserDatabase configured in the global JNDI
               resources under the key "UserDatabase".  Any edits
               that are performed against this UserDatabase are immediately
               available for use by the Realm.  --&gt;
          &lt;Realm className="org.apache.catalina.realm.UserDatabaseRealm"
                 resourceName="UserDatabase"/&gt;
        &lt;/Realm&gt;
  
        &lt;Host name="localhost"  appBase="app2"
              unpackWARs="true" autoDeploy="true"&gt;
  
          &lt;!-- SingleSignOn valve, share authentication between web applications
               Documentation at: /docs/config/valve.html --&gt;
          &lt;!--
          &lt;Valve className="org.apache.catalina.authenticator.SingleSignOn" /&gt;
          --&gt;
  
          &lt;!-- Access log processes all example.
               Documentation at: /docs/config/valve.html
               Note: The pattern used is equivalent to using pattern="common" --&gt;
          &lt;Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
                 prefix="localhost_access_log" suffix=".txt"
                 pattern="%h %l %u %t &amp;quot;%r&amp;quot; %s %b" /&gt;
  
        &lt;/Host&gt;
      &lt;/Engine&gt;
    &lt;/Service&gt;
  
  &lt;/Server&gt;
  </code></pre>
  
  <p>and here is <code>catalina.out</code>:</p>
  
  <pre class="lang-none prettyprint-override"><code>Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.ClassLoaderFactory validateFile
  WARNING: Problem with directory [/usr/share/tomcat8/common/classes], exists: [false], isDirectory: [false], can
  Read: [false]
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.ClassLoaderFactory validateFile
  WARNING: Problem with directory [/usr/share/tomcat8/common], exists: [false], isDirectory: [false], canRead: [f
  alse]
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.ClassLoaderFactory validateFile
  WARNING: Problem with directory [/usr/share/tomcat8/server/classes], exists: [false], isDirectory: [false], can
  Read: [false]
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.ClassLoaderFactory validateFile
  WARNING: Problem with directory [/usr/share/tomcat8/server], exists: [false], isDirectory: [false], canRead: [f
  alse]
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.ClassLoaderFactory validateFile
  WARNING: Problem with directory [/usr/share/tomcat8/shared/classes], exists: [false], isDirectory: [false], can
  Read: [false]
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.ClassLoaderFactory validateFile
  WARNING: Problem with directory [/usr/share/tomcat8/shared], exists: [false], isDirectory: [false], canRead: [f
  alse]
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Server version: Apache Tomcat/8.0.14 (Debian)
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Server built:   Sep 29 2014 11:26:22
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Server number:  8.0.14.0
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.VersionLoggerListener log
  INFO: OS Name:        Linux
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.VersionLoggerListener log
  INFO: OS Version:     3.16.0-4-amd64
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Architecture:   amd64
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.VersionLoggerListener log
  INFO: JVM Version:    1.8.0_60-b27
  Nov 02, 2015 3:51:07 PM org.apache.catalina.startup.VersionLoggerListener log
  INFO: JVM Vendor:     Oracle Corporation
  Nov 02, 2015 3:51:08 PM org.apache.coyote.AbstractProtocol init
  INFO: Initializing ProtocolHandler ["http-nio-8080"]
  Nov 02, 2015 3:51:08 PM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
  INFO: Using a shared selector for servlet write/read
  Nov 02, 2015 3:51:08 PM org.apache.coyote.AbstractProtocol init
  INFO: Initializing ProtocolHandler ["http-nio-8888"]
  Nov 02, 2015 3:51:08 PM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
  INFO: Using a shared selector for servlet write/read
  Nov 02, 2015 3:51:08 PM org.apache.catalina.startup.Catalina load
  INFO: Initialization processed in 1064 ms
  Nov 02, 2015 3:51:08 PM org.apache.catalina.core.StandardService startInternal
  INFO: Starting service app1
  Nov 02, 2015 3:51:08 PM org.apache.catalina.core.StandardEngine startInternal
  INFO: Starting Servlet Engine: Apache Tomcat/8.0.14 (Debian)
  Nov 02, 2015 3:51:08 PM org.apache.catalina.startup.HostConfig deployDescriptor
  INFO: Deploying configuration descriptor /etc/tomcat8/app1/localhost/ROOT.xml
  Nov 02, 2015 3:51:08 PM org.apache.catalina.core.ContainerBase addChildInternal
  SEVERE: ContainerBase.addChild: start:
  org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[app1].StandardHost[localhost].StandardContext[]]
          at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
          at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:724)
          at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:700)
          at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:714)
          at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:581)
          at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1685)
          at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
          at java.util.concurrent.FutureTask.run(FutureTask.java:266)
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
          at java.lang.Thread.run(Thread.java:745)
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.webresources.StandardRoot@31bb7338]
          at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
          at org.apache.catalina.core.StandardContext.resourcesStart(StandardContext.java:4900)
          at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5029)
          at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
          ... 10 more
  Caused by: java.lang.IllegalArgumentException: The main resource set specified [/var/lib/tomcat8/app1/ROOT] is not valid
          at org.apache.catalina.webresources.StandardRoot.startInternal(StandardRoot.java:665)
          at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
          ... 13 more
  
  Nov 02, 2015 3:51:08 PM org.apache.catalina.startup.HostConfig deployDescriptor
  SEVERE: Error deploying configuration descriptor /etc/tomcat8/app1/localhost/ROOT.xml
  java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[app1].StandardHost[localhost].StandardContext[]]
          at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:727)
          at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:700)
          at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:714)
          at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:581)
          at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1685)
          at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
          at java.util.concurrent.FutureTask.run(FutureTask.java:266)
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
          at java.lang.Thread.run(Thread.java:745)
  
  Nov 02, 2015 3:51:08 PM org.apache.catalina.startup.HostConfig deployDescriptor
  INFO: Deployment of configuration descriptor /etc/tomcat8/app1/localhost/ROOT.xml has finished in 97 ms
  Nov 02, 2015 3:51:08 PM org.apache.coyote.AbstractProtocol start
  INFO: Starting ProtocolHandler ["http-nio-8080"]
  Nov 02, 2015 3:51:08 PM org.apache.catalina.core.StandardService startInternal
  INFO: Starting service app2
  Nov 02, 2015 3:51:08 PM org.apache.catalina.core.StandardEngine startInternal
  INFO: Starting Servlet Engine: Apache Tomcat/8.0.14 (Debian)
  Nov 02, 2015 3:51:08 PM org.apache.catalina.startup.HostConfig deployDescriptor
  INFO: Deploying configuration descriptor /etc/tomcat8/app2/localhost/ROOT.xml
  </code></pre>
  
  <p>The rest is log from app2 booting ok. I have set up context in <code>/var/lib/tomcat8/app1/localhost/ROOT.xml</code> which is merely:  </p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;Context&gt;
      &lt;Resources&gt;
          &lt;PreResources className="org.apache.catalina.webresources.DirResourceSet"
          base="/var/lib/app1-resources" webAppMount="/WEB-INF/classes/config" /&gt;
      &lt;/Resources&gt;
  &lt;/Context&gt;
  </code></pre>
  
  <p>I checked for permissions and ownership but it seems right, knowing that it is identical to that of a app2 which works fine. I copied ROOT.war and checked its checksum to make sure it didn't get corrupted on the way. I checked config xmls with xmllint for parsing errors but there were none. 
  I think that this may be configuration error on my side but apart from the fact that app2 is working I've previously set up two apps on one tomcat8 instance and it worked ok.
  Can someone help me out? </p>