Apache Tomcat 9 Configuration Reference

Set this to a comma separated list of fully qualified name of classes that implement org.apache.tomcat.util.IntrospectionUtils.PropertySource. Required to have a public constructor with no arguments.

Use this to add a property source, that will be invoked when ${parameter:default-value} denoted parameters (with optional default values) are found in the XML files that Tomcat parses.

Property replacement from the specified property source on the JVM system properties can also be done using the REPLACE_SYSTEM_PROPERTIES system property.

org.apache.tomcat.util.digester.EnvironmentPropertySource can be used to replace parameters from the process' environment variables, e.g. injected ConfigMaps or Secret objects in container based systems like OpenShift or Kubernetes.

Set this boolean system property to true to cause property replacement from the digester property source on the JVM system properties.

This system property is deprecated and will be removed without replacement in Apache Tomcat 10 onwards.

If true, the clustering module will attempt to use DNS to resolve any host names provided in the cluster configuration.

If not specified, the default value of false will be used.

The number of javax.el.BeanELResolver.BeanProperties objects that will be cached by the EL Parser.

If not specified, the default of 1000 will be used.

The number of parsed EL expressions that will be cached by the EL Parser.

If not specified, the default of 5000 will be used.

If true, when coercing nulls to objects of type Number, Character or Boolean the result will be 0 for Number and Character types and false for Boolean as required by the EL 2.2 and earlier specifications. If this property is false the result of the coercion will be null as required by the EL 3.0 specification.

If not specified, the default value of false will be used.

If true, when parsing expressions, identifiers will not be checked to ensure that they conform to the Java Language Specification for Java identifiers.

If not specified, the default value of false will be used.

By default, JSPs that use their own base class via the extends attribute of the page directive, will have Tag pooling disabled since Jasper cannot guarantee that the necessary initialisation will have taken place. This can have a negative impact on performance. Providing the alternative base class calls _jspInit() from Servlet.init(), setting this property to true will enable pooling with an alternative base class. If the alternative base class does not call _jspInit() and this property is true, NPEs will occur when attempting to use tags.

If not specified, the default value of false will be used.

If true, the requirement to have the object referenced in jsp:getProperty action to be previously "introduced" to the JSP processor, as specified in the chapter JSP.5.3 of JSP 2.0 and later specifications, is enforced.

If not specified, the specification compliant default of true will be used.

The name of the variable to use for the expression language expression factory.

If not specified, the default value of _el_expressionfactory will be used.

The name of the variable to use for the instance manager factory.

If not specified, the default value of _jsp_instancemanager will be used.

If false the requirements for whitespace before an attribute name will be relaxed so that the lack of whitespace will not cause an error.

If not specified, the specification compliant default of true will be used.

The size (in characters) to use when creating a tag buffer.

If not specified, the default value of org.apache.jasper.Constants.DEFAULT_TAG_BUFFER_SIZE (512) will be used.

If true, any tag buffer that expands beyond org.apache.jasper.runtime.BodyContentImpl.BUFFER_SIZE will be destroyed and a new buffer created.

If not specified, the default value of false will be used.

If true, a ThreadLocal PageContext pool will be used.

If not specified, the default value of true will be used.

The size of the ThreadLocal PageContext.

If not specified, the default value of 8 will be used.

The base class of the Servlets generated from the JSPs.

If not specified, the default value of org.apache.jasper.runtime.HttpJspBase will be used.

The name of the service method called by the base class.

If not specified, the default value of _jspService will be used.

The name of the ServletContext attribute that provides the classpath for the JSP.

If not specified, the default value of org.apache.catalina.jsp_classpath will be used.

The name of the request attribute for <jsp-file> element of a servlet definition. If present on a request, this overrides the value returned by request.getServletPath() to select the JSP page to be executed.

If not specified, the default value of org.apache.catalina.jsp_file will be used.

Deprecated: This will be removed in Tomcat 9.0.x onwards. It is replaced by the use of the jspFile servlet initialisation parameter

The name of the query parameter that causes the JSP engine to just pregenerate the servlet but not invoke it.

If not specified, the default value of jsp_precompile will be used, as defined by JSP specification (JSP.11.4.2).

The default package name for compiled JSPs.

If not specified, the default value of org.apache.jsp will be used.

The default package name for tag handlers generated from tag files.

If not specified, the default value of org.apache.jsp.tag will be used.

The servlet context attribute under which the alternate deployment descriptor for this web application is stored.

If not specified, the default value of org.apache.catalina.deploy.alt_dd will be used.

Prefix to use for generated temporary variable names.

If not specified, the default value of _jspx_temp will be used.

If true, the instance manager is used to obtain tag handler instances.

If not specified, the default value of false will be used.

If this is true or if a security manager is in use a new facade object will be created for each request.

If not specified, the default value of false will be used.

If this is true the '\' character will be permitted as a path delimiter.

If not specified, the default value of false will be used.

Use of this system property is deprecated. It will be removed from Tomcat 10 onwards.

If this system property is set to true, the default for the encodedSolidusHandling attribute of all Connectors will be changed from reject to decode. If decoded, it will be treated a path delimiter.

The default value of this system property is false.

If this is true the default values will be changed for:

• org.apache.catalina.core.
ApplicationContext.GET_RESOURCE_REQUIRE_SLASH
• org.apache.catalina.core.
ApplicationDispatcher.WRAP_SAME_OBJECT
• org.apache.catalina.core.
StandardHostValve.ACCESS_SESSION
• org.apache.catalina.session.
StandardSession.ACTIVITY_CHECK
• org.apache.catalina.session.
StandardSession.LAST_ACCESS_AT_START
• org.apache.tomcat.util.http.
ServerCookie.STRICT_NAMING
• The resourceOnlyServlets attribute of any Context element.
• The tldValidation attribute of any Context element.
• The useRelativeRedirects attribute of any Context element.
• The xmlNamespaceAware attribute of any Context element.
• The xmlValidation attribute of any Context element.

If this is true then a call to Response.getWriter() if no character encoding has been specified will result in subsequent calls to Response.getCharacterEncoding() returning ISO-8859-1 and the Content-Type response header will include a charset=ISO-8859-1 component. (SRV.15.2.22.1)

If not specified, the default specification compliant value of true will be used.

If this is true then the path passed to ServletContext.getResource() or ServletContext.getResourceAsStream() must start with "/". If false, code like getResource("myfolder/myresource.txt") will work as Tomcat will prepend "/" to the provided path.

If org.apache.catalina.STRICT_SERVLET_COMPLIANCE is set to true, the default of this setting will be true, else the default value will be false.

If this is true then any wrapped request or response object passed to an application dispatcher will be checked to ensure that it has wrapped the original request or response.

If org.apache.catalina.STRICT_SERVLET_COMPLIANCE is set to true, the default of this setting will be true, else the default value will be false.

The default value of this system property is false.

If this is true the default values will be changed for:

• org.apache.tomcat.websocket.server#isEnforceNoAddAfterHandshake (default changes from false to true)

If this is true then the requirements of the Servlet specification that Cookie names must adhere to RFC2109 will be enforced. If this is false the naming rules specified in RFC6265 (allow the leading "$") will be used.

If org.apache.catalina.STRICT_SERVLET_COMPLIANCE is set to true, the default of this setting will be true, else the default value will be false.

An alternative name for the single sign on session cookie. Defaults to JSESSIONIDSSO.

If this is true, every request that is associated with a session will cause the session's last accessed time to be updated regardless of whether or not the request explicitly accesses the session.

If org.apache.catalina.STRICT_SERVLET_COMPLIANCE is set to true, the default of this setting will be true, else the default value will be false.

If this is true, Tomcat will track the number of active requests for each session. When determining if a session is valid, any session with at least one active request will always be considered valid.

If org.apache.catalina.STRICT_SERVLET_COMPLIANCE is set to true, the default of this setting will be true, else the default value will be false.

If this is true, the last accessed time for sessions will be calculated from the beginning of the previous request. If false, the last accessed time for sessions will be calculated from the end of the previous request. This also affects how the idle time is calculated.

If org.apache.catalina.STRICT_SERVLET_COMPLIANCE is set to true, the default of this setting will be true, else the default value will be false.

If no logging configuration file is specified and no logging configuration class is specified using the java.util.logging.config.class and java.util.logging.config.file properties the default logging framework org.apache.juli will use the default java.util.logging.SimpleFormatter for all console output. To simply override the console output formatter, one can use the described property. Example: -Dorg.apache.juli.formatter=org.apache.juli.OneLineFormatter

The maximum number of log records that the JULI AsyncFileHandler will queue in memory. New records are added to the queue and get asynchronously removed from the queue and written to the files by a single writer thread. When the queue is full and a new record is being logged the log record will be handled based on the org.apache.juli.AsyncOverflowDropType setting.

The default value is 10000 records. This number represents the global number of records, not on a per handler basis.

When the queue of log records of the JULI AsyncFileHandler is full, new log records are handled according to the following setting:

• 1 - the newest record in the queue will be dropped and not logged
• 2 - the oldest record in the queue will be dropped and not logged
• 3 - suspend the logging thread until older records got written to the log file and the queue is no longer full. This is the only setting that ensures that no messages get lost.
• 4 - drop the current log record

The default value is 1 (drop the newest record in the queue).

The poll interval in milliseconds for the asynchronous logger thread. If the log queue is empty, the async thread will issue a poll(poll interval) in order to not wake up too often.

The default value is 1000 milliseconds.

The type of logging to use for errors generated by invalid input data. The options are: DEBUG_ALL, INFO_THEN_DEBUG, INFO_ALL and NONE. When INFO_THEN_DEBUG is used, the period for which errors are logged at DEBUG rather than INFO is controlled by the system property org.apache.juli.logging.UserDataHelper.SUPPRESSION_TIME.

The default value is INFO_THEN_DEBUG.

The errors currently logged using this system are:

• invalid cookies;
• invalid parameters;
• too many headers, too many parameters (hitting maxHeaderCount or maxParameterCount limits of a connector).
• invalid host names

Other errors triggered by invalid input data may be added to this system in later versions.

When using INFO_THEN_DEBUG for org.apache.juli.logging.UserDataHelper.CONFIG this system property controls how long messages are logged at DEBUG after a message has been logged at INFO. Once this period has elapsed, the next message will be logged at INFO followed by a new suppression period where messages are logged at DEBUG and so on. The value is measured in seconds.

A value of 0 is equivalent to using INFO_ALL for org.apache.juli.logging.UserDataHelper.CONFIG.

A negative value means an infinite suppression period.

The default value is 86400 (24 hours).

A list of comma-separated file name patters that is used as the default value for pluggabilitySkip and tldSkip attributes of the standard JarScanFilter implementation.

The coded default is empty, however the system property is set in a default Tomcat installation via the $CATALINA_BASE/conf/catalina.properties file.

A list of comma-separated file name patters that is used as the default value for pluggabilityScan and tldScan attributes of the standard JarScanFilter implementation.

The coded default is empty, however the system property is set in a default Tomcat installation via the $CATALINA_BASE/conf/catalina.properties file.

If true, allow unknown extensions to be declared by the user.

The default value is false.

The default size for buffers used in the Websockets container.

The default value is 8192 which corresponds to 8KB.

Default value of the origin header that will be sent by the client during the upgrade handshake.

The default is null so that no origin header is sent.

The number of periodic ticks between periodic processing which involves in particular session expiration checks.

The default value is 10 which corresponds to 10 seconds.

If true, disable all built-in extensions provided by the server, such as message compression.

The default value is false.

If this is false it will override the useNaming attribute for all Context elements.

The class name of the factory to use to create resources of type javax.sql.DataSource. If not specified the default of org.apache.tomcat.dbcp.dbcp2.BasicDataSourceFactory is used which is a package renamed (to avoid conflicts) copy of Apache Commons DBCP 2.

The class name of the factory to use to create resources of type javax.mail.Session. If not specified the default of org.apache.naming.factory.MailSessionFactory is used.

Provides a default value for the jvmRoute attribute of the Engine element. It does not override the value configured on the Engine element.

The location from which to load the catalina.properties configuration file. This may be an absolute URL, a relative (to the current working directory) URL or an alternative file name in which case Tomcat will attempt to load the file from the default location of $CATALINA_BASE/conf/.

If true, the String cache is enabled for ByteChunk.

If not specified, the default value of false will be used.

If true, the String cache is enabled for CharChunk.

If not specified, the default value of false will be used.

The number of times toString() must be called before the cache is activated.

If not specified, the default value of 20000 will be used.

The size of the String cache.

If not specified, the default value of 200 will be used.

The character to use to separate the WAR file and WAR content parts of a WAR URL using the custom WAR scheme provided by Tomcat. This is equivalent to how ! is used in JAR URLs.

If not specified, the default value of * will be used.

The maximum length of String that will be cached.

If not specified, the default value of 128 will be used.

The size of the cache to use parsed and formatted date value.

If not specified, the default value of 1000 will be used.

If true, use a shared selector for servlet write/read.

If not specified, the default value of true will be used.

If true, the server will exit if an exception happens during the server initialization phase. To support this feature, this system property is used as the default for the throwOnFailure attribute of a Connector.

If not specified, the default value of false will be used.

The CombinedRealm allows nested Realms. This property controls the maximum permitted number of levels of nesting.

If not specified, the default value of 3 will be used.

The NestedCredentialHandler allows nested CredentialHandlers. This property controls the maximum permitted number of levels of nesting.

If not specified, the default value of 3 will be used.