Tomcat FAQ

Modified on Tue, Mar 26 at 11:14 AM

Apache Tomcat FAQ

How to hide the Server Version from all error messages generated by Apache Tomcat

In this example, Apache Tomcat is installed in c:\schoolfi-tomcat

Make this directory: c:\schoolfi-tomcat\lib\org\apache\catalina\util

Create a new text file: ServerInfo.properties

Put this one line of text in the file:

server.info=Generic Web Server

Restart Tomcat

The error message should look like this now:

Garbage 1 Collector in JDK 7u5

Documentation here: Garbage 1 Collector doc in jdk1.70_04

To enable: add this to Tomcat -XX:+UseG1GC

Only use with JVM Heap Sizes of 6 Gig or more

Max Request Parameters Error In catalina.out or genesis.log

The exact error message is:

INFO: More than the maximum number of request parameters (GET plus POST) for a single request ([10,000]) were detected. Any parameters beyond this limit have be en ignored. To change this limit, set the maxParameterCount attribute on the Connector.

In the server.xml, you want to add maxParameterCount="100000" to all Connectors. For example:

<Connector port="8080" protocol="HTTP/1.1"
  connectionTimeout="20000"
  redirectPort="8443" 
  maxParameterCount="100000" />

On Windows; Tomcat fails to start as a service. No error seems to be reported anywhere.

This usually occurs during a fresh installation of Tomcat. The problem is that the newer versions of Java 1.6 do not include a crucial DLL for the service to start. To fix, perform this task:

Determine where your JDK is installed. It is almost always in c:\jdk1.6.0_07.

Determine where your Tomcat is installed. It is almost always in c:\tomcat.
Run this command (fill the in the drive and paths with the correct values)
Copy c:\jdk1.6.0_05\bin\msvcrt71.dll c:\tomcat\bin

Server hangs: java.lang.OutOfMemoryError: PermGen space appears in the Tomcat log file.

This log file can usually be found in either c:\tomcat\logs or /usr/tomcat/logs. The server will stop accepting new connections; and this error may appear in the log file.

The Java runtime does not have enough PermGen allocated.

To correct this on Windows: (Tomcat may be on another drive in your installation)

c:\> net stop "Apache Tomcat"

c:\> cd \tomcat\bin

C:\tomcat\bin> tomcat6w

Click on the Java tab; and add this line to the bottom of the text box

-XX:MaxPermSize=384m

To correct this on Linux / Solaris / Mac OS/X: Logon on as root.

# cd /usr/tomcat/bin

# ./shutdown.sh

# vi setenv.sh

Add the -XX:MaxPermSize=384m to your environment string. Your file should look something like this when your done:

CATALINA_OPTS="-Xmx5000m -Xms5000m -server -d64 -XX:MaxPermSize=768m -Djava.awt.headless=true"

CATALINA_PID="/var/run/genesis.pid"

Start Tomcat back up

# nohup ./startup.sh &

How do I configure Tomcat to connect to Oracle RAC?

First, you will need to know the service name of the RAC installation. To find this out; log onto the Oracle server and run this command (any platform)

c:\> lsnrctl status

....

Edit the /usr/tomcat/conf/Catalina/localhost/instance.xml file.

HTTP Status 403 - The request body was too large to be cached during the authentication process

This error may occur when a user is automatically logged out; and they hit a save button on certain screens with large amounts of content. (Screens like GRadebook, Grade Posting etc...).

When a user is forced to re-logon; Tomcat (The webserver) will cache the data from the page they were on; and then use it after succesfull logon. The default limit of the cached data is 4 kilobytes.

To change this limit; open the server.xml file on your tomcat installation. On Unix operating systems, this file is generally in /usr/tomcat/conf/server.xml. On Windows operating systems this file is generally in c:\tomcat\conf\server.xml.

In the Connector(s) blocks of the server.xml, add the maxSavePostSize parameter; and set it to -1 to allow an unlimited sized post to be cached. Here is an example of that file:

<Server port="8005" shutdown="SHUTDOWN">

  <Service name="Catalina">

    <Connector port="80" maxHttpHeaderSize="8192"

               maxThreads="150" minSpareThreads="25" maxSpareThreads="75"

               enableLookups="false" redirectPort="8443" acceptCount="100"

               connectionTimeout="20000" disableUploadTimeout="true"

               maxSavePostSize="-1"     />

 <Engine name="Catalina" defaultHost="localhost">

          <Host name="localhost" appBase="webapps" unpackWARs="false" autoDeploy="false"

                xmlValidation="false" xmlNamespaceAware="false"/>

    </Engine>

  </Service>

</Server>

Restart Tomcat to have this go into effect.

Autostarting Tomcat on Redhat Linux

Create the file /etc/init.d/genesis

#!/bin/sh

# chkconfig: 345 99 10

# description: Genesis Autostart Script

case "$1" in

    'start')

        # Start genesis

        # The following command assumes that the oracle login

        # will not prompt the user for any values

        su - -c "nohup /usr/tomcat/bin/startup.sh &"

;;

    'stop')

        # Stop the Oracle databases:

        # The following command assumes that the oracle login

        # will not prompt the user for any values

        su - -c "/usr/tomcat/bin/shutdown.sh"

;;

esac

Run these commands:

# chmod 775 /etc/init.d/genesis

# ln -s /etc/init.d/genesis /etc/rc.d/rc0.d/K01genesis

# ln -s /etc/init.d/genesis /etc/rc.d/rc3.d/S99genesis

# ln -s /etc/init.d/genesis /etc/rc.d/rc5.d/S99genesis

# chkconfig --level 345 genesis on

Page that redirects to another site

If you are site is going to be hosted on the ASP in case of an emergency; the following
login.jsp could be used (/usr/tomcat/webapps/district/login.jsp)

<%@ page import="com.genesis.sis.CommonValidations"%>

<%@ page import="com.genesis.sis.beans.AuditSecurity"%>

<%@ page import="com.genesis.sis.beans.GenesisSystem" %>

<%@ page import="com.genesis.sis.SystemInfo" %>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<%

    String test = request.getServerName().toLowerCase();

    if (test.contains("parents"))

        response.sendRedirect("http://parents.genesisedu.com/district");

    else

        response.sendRedirect("http://genesis.genesisedu.com/district");

%>

Upgraded to Tomcat 8 and servers startup fails on Windows with the following exception

SEVERE [main] org.apache.coyote.AbstractProtocol.init Failed to initialize end point associated with ProtocolHandler ["http-nio-443"]
java.net.MalformedURLException: unknown protocol: c

A simple configuration change in the server.xml is required:

The problem is the keystoreFile attribute on the Connector element. Tomcat 8 requires that on Windows servers backslashes be used instead of forward slashed.

<Connector port="443"

               enableLookups="false"

               connectionTimeout="20000" scheme="https"

               sslProtocol="TLS" secure="true" SSLEnabled="true"

               keystoreFile="c:/genesis/ssl/genesis.jks"

               keystorePass="sch00lisc00l"

               keystoreType="JKS" />

Change c:/genesis/ssl/genesis.jks to c:\\genesis\\ssl\\genesis.jks

Be sure to use double backslashes for the path separators.

Is your district using Cisco DUO / OAuth 2.0 for authentication?

The following Tomcat - genesis.xml parameter is not compatible with OAuth 2.0