Links Top Level Elements Executors Connectors Containers Nested Components Cluster Elements web.xml Other | System Properties| Introduction |
The following sections list the system properties that may be set to modify
the default Tomcat behaviour.
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| Property replacements |
| Property | Description |
|---|
org.apache.tomcat.util.digester. PROPERTY_SOURCE |
Set this to a fully qualified name of a class that implements
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.
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.
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|
| Clustering |
| Property | Description |
|---|
org.apache.catalina. tribes.dns_lookups |
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.
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|
| Expression Language |
| Property | Description |
|---|
org.apache.el.BeanELResolver. CACHE_SIZE |
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.
| org.apache.el.ExpressionBuilder. CACHE_SIZE |
The number of parsed EL expressions that will be cached by the EL
Parser.
If not specified, the default of 5000 will be used.
| org.apache.el.parser. COERCE_TO_ZERO |
If true, when coercing expressions to numbers
"" and null will be coerced to zero as required
by the specification.
If not specified, the default value of true will be used.
| org.apache.el.parser. SKIP_IDENTIFIER_CHECK |
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.
|
|
| Jasper |
| Property | Description |
|---|
org.apache.jasper.compiler. Generator.POOL_TAGS_WITH_EXTENDS |
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.
| org.apache.jasper.compiler. Generator.STRICT_GET_PROPERTY |
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.
| org.apache.jasper.compiler. Generator.VAR_EXPRESSIONFACTORY |
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.
| org.apache.jasper.compiler. Generator.VAR_INSTANCEMANAGER |
The name of the variable to use for the instance manager factory.
If not specified, the default value of _jsp_instancemanager
will be used.
| org.apache.jasper.compiler. Parser.STRICT_QUOTE_ESCAPING |
If false the requirements for escaping quotes in JSP
attributes will be relaxed so that an unescaped quote will not
cause an error.
If not specified, the specification compliant default of
true will be used.
| org.apache.jasper.compiler. Parser.STRICT_WHITESPACE |
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.
| org.apache.jasper.runtime. BodyContentImpl.BUFFER_SIZE |
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.
| org.apache.jasper.runtime. BodyContentImpl.LIMIT_BUFFER |
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.
| org.apache.jasper.runtime. JspFactoryImpl.USE_POOL |
If true, a ThreadLocal PageContext pool will
be used.
If not specified, the default value of true will be used.
| org.apache.jasper.runtime. JspFactoryImpl.POOL_SIZE |
The size of the ThreadLocal PageContext.
If not specified, the default value of 8 will be used.
| org.apache.jasper.Constants. JSP_SERVLET_BASE |
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.
| org.apache.jasper.Constants. SERVICE_METHOD_NAME |
The name of the service method called by the base class.
If not specified, the default value of _jspService
will be used.
| org.apache.jasper.Constants. SERVLET_CLASSPATH |
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.
| org.apache.jasper.Constants. JSP_FILE |
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
| org.apache.jasper.Constants. PRECOMPILE |
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).
| org.apache.jasper.Constants. JSP_PACKAGE_NAME |
The default package name for compiled jsp pages.
If not specified, the default value of org.apache.jsp
will be used.
| org.apache.jasper.Constants. TAG_FILE_PACKAGE_NAME |
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.
| org.apache.jasper.Constants. ALT_DD_ATTR |
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.
| org.apache.jasper.Constants. TEMP_VARIABLE_NAME_PREFIX |
Prefix to use for generated temporary variable names.
If not specified, the default value of _jspx_temp
will be used.
| org.apache.jasper.Constants. USE_INSTANCE_MANAGER_FOR_TAGS |
If true, the instance manager is used to obtain tag
handler instances.
If not specified, the default value of false will be used.
|
|
| Security |
| Property | Description |
|---|
org.apache.catalina.connector. RECYCLE_FACADES |
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.
| org.apache.catalina.connector. CoyoteAdapter.ALLOW_BACKSLASH |
If this is true the '\' character will be permitted as a
path delimiter.
If not specified, the default value of false will be used.
| org.apache.tomcat.util.buf. UDecoder.ALLOW_ENCODED_SLASH |
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.
|
|
| Specification |
| Property | Description |
|---|
org.apache.catalina. STRICT_SERVLET_COMPLIANCE |
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_SLASHorg.apache.catalina.core.
ApplicationDispatcher.WRAP_SAME_OBJECTorg.apache.catalina.core.
StandardHostValve.ACCESS_SESSIONorg.apache.catalina.session.
StandardSession.ACTIVITY_CHECKorg.apache.catalina.session.
StandardSession.LAST_ACCESS_AT_STARTorg.apache.tomcat.util.http.
ServerCookie.ALWAYS_ADD_EXPIRESorg.apache.tomcat.util.http.
ServerCookie.FWD_SLASH_IS_SEPARATORorg.apache.tomcat.util.http.
ServerCookie.PRESERVE_COOKIE_HEADERorg.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.
Note that changing a number of the above defaults is likely to break
the majority of systems as some browsers are unable to correctly handle
the cookie headers that result from a strict adherence to the
specifications. Defaults, regardless of whether or not they have been
changed by setting
org.apache.catalina.STRICT_SERVLET_COMPLIANCE can always be
overridden by explicitly setting the appropriate system property or element
attribute.
| org.apache.catalina.connector. Response.ENFORCE_ENCODING_IN_GET_WRITER |
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.
| org.apache.catalina.core.ApplicationContext .GET_RESOURCE_REQUIRE_SLASH |
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.
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.
| org.apache.catalina.core. ApplicationDispatcher.WRAP_SAME_OBJECT |
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.
| org.apache.tomcat.util.http. ServerCookie.ALLOW_EQUALS_IN_VALUE |
If this is true Tomcat will allow '='
characters when parsing unquoted cookie values. If false,
cookie values containing '=' will be terminated when the
'=' is encountered and the remainder of the cookie value will
be dropped.
If not specified, the default value specification compliant value of
false will be used.
| org.apache.tomcat.util.http. ServerCookie.ALLOW_HTTP_SEPARATORS_IN_V0 |
If this is true Tomcat will allow HTTP separators in
cookie names and values.
If not specified, the default specification compliant value of
false will be used.
| org.apache.tomcat.util.http. ServerCookie.ALLOW_NAME_ONLY |
If this is false then the requirements of the cookie
specifications that cookies must have values will be enforced and cookies
consisting only of a name but no value will be ignored.
If not specified, the default specification compliant value of
false will be used.
| org.apache.tomcat.util.http. ServerCookie.ALWAYS_ADD_EXPIRES |
If this is true Tomcat will always add an expires
parameter to a SetCookie header even for cookies with version greater than
zero. This is to work around a known IE6 and IE7 bug that causes IE to
ignore the Max-Age parameter in a SetCookie header.
If org.apache.catalina.STRICT_SERVLET_COMPLIANCE is set to
true, the default of this setting will be false,
else the default value will be true.
| org.apache.tomcat.util.http. ServerCookie.FWD_SLASH_IS_SEPARATOR |
If this is true then the / (forward slash) character will
be treated as a separator. Note that this character is frequently used in
cookie path attributes and some browsers will fail to process a cookie if
the path attribute is quoted as is required by a strict adherence to the
specifications. This is highly likely to break session tracking using
cookies.
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.
| org.apache.tomcat.util.http. ServerCookie.PRESERVE_COOKIE_HEADER |
If this is true Tomcat will ensure that cookie
processing does not modify cookie header returned by
HttpServletRequest.getHeader().
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.
| org.apache.tomcat.util.http. ServerCookie.STRICT_NAMING |
If this is true then the requirements of the Servlet specification
that Cookie names must adhere to RFC2109 (no use of separators) will be
enforced.
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.
|
|
| Sessions |
| Property | Description |
|---|
org.apache.catalina.authenticator. Constants.SSO_SESSION_COOKIE_NAME |
An alternative name for the single sign on session cookie. Defaults to
JSESSIONIDSSO.
| org.apache.catalina.core. StandardHostValve.ACCESS_SESSION |
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.
| org.apache.catalina.session. StandardSession.ACTIVITY_CHECK |
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.
| org.apache.catalina.session. StandardSession.LAST_ACCESS_AT_START |
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.
|
|
| Logging |
| Property | Description |
|---|
org.apache.juli.formatter |
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
| org.apache.juli. AsyncOverflowDropType |
When the memory limit of records has been reached the system needs to determine what action to take.
Currently there are three actions that can be taken:
int OVERFLOW_DROP_LAST = 1 - the record that caused the overflow will be dropped and not loggedint OVERFLOW_DROP_FIRST = 2 - the record that is next in line to be logged will be dropped to make room for the latest record on the queueint OVERFLOW_DROP_FLUSH = 3 - suspend the thread while the queue empties out and flushes the entries to the write bufferint OVERFLOW_DROP_CURRENT = 4 - drop the current log entry
The default value is 1 (OVERFLOW_DROP_LAST).
| org.apache.juli. AsyncMaxRecordCount |
The max number of log records that the async logger will keep in memory. When this limit is reached and a new record is being logged by the
JULI framework the system will take an action 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.
| org.apache.juli. AsyncLoggerPollInterval |
The poll interval in milliseconds for the asynchronous logger thread in milliseconds.
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.
| org.apache.juli.logging. UserDataHelper.CONFIG |
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.
| org.apache.juli.logging. UserDataHelper.SUPPRESSION_TIME |
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).
|
|
| JAR Scanning |
| Property | Description |
|---|
tomcat.util.scan. DefaultJarScanner.jarsToSkip |
The comma-separated list of file name patterns of JARs that Tomcat will
not scan for configuration information when using the
JarScanner functionality. The file name
pattern syntax is described in
JarScanner documentation. Note that
there are additional system properties that enable JARs to be excluded
from specific scans rather than all scans.
The coded default is that no JARs are skipped however the system
property is set in a default Tomcat installation via the
$CATALINA_BASE/conf/catalina.properties file.
| org.apache.catalina.startup. ContextConfig.jarsToSkip |
The comma-separated list of additional filenames of JARs that Tomcat
will not scan for Servlet 3.0 pluggability features.
The coded default is that no JARs are skipped however the system
property is set in a default Tomcat installation via the
$CATALINA_BASE/conf/catalina.properties file.
| org.apache.catalina.startup. TldConfig.jarsToSkip |
The comma-separated list of additional filenames of JARs that Tomcat
will not scan for TLDs.
The coded default is that no JARs are skipped however the system
property is set in a default Tomcat installation via the
$CATALINA_BASE/conf/catalina.properties file.
|
|
| Websockets |
| Property | Description |
|---|
org.apache.tomcat .websocket.ALLOW_UNSUPPORTED_EXTENSIONS |
If true, allow unknown extensions to be declared by
the user.
The default value is false.
| org.apache.tomcat. websocket.DEFAULT_BUFFER_SIZE |
The default size for buffers used in the Websockets container.
The default value is 8192 which corresponds to 8KB.
| org.apache.tomcat. websocket.DEFAULT_ORIGIN_HEADER_VALUE |
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.
| org.apache.tomcat. websocket.DEFAULT_PROCESS_PERIOD |
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.
| org.apache.tomcat. websocket.DISABLE_BUILTIN_EXTENSIONS |
If true, disable all built-in extensions provided by the
server, such as message compression.
The default value is false.
|
|
| Other |
| Property | Description |
|---|
org.apache.coyote. USE_CUSTOM_STATUS_MSG_IN_HEADER | If this is
true, custom HTTP status messages will be used within HTTP
headers. If a custom message is specified that is not valid for use in an
HTTP header (as defined by RFC2616) then the custom message will be
ignored and the default message used.
If not specified, the default value of false will be used.
| catalina.useNaming |
If this is false it will override the
useNaming attribute for all
Context elements.
| javax.sql.DataSource.Factory |
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.dbcp.BasicDataSourceFactory is used
which is a package renamed (to avoid conflicts) copy of
Apache Commons DBCP 1.x.
| javax.mail.Session.Factory |
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.
| jvmRoute |
Provides a default value for the jvmRoute attribute of the
Engine element. It does not override the value
configured on the Engine element.
| catalina.config |
The URL for the catalina.properties configuration file.
| tomcat.util.buf.StringCache.byte.enabled |
If true, the String cache is enabled for
ByteChunk.
If not specified, the default value of false will be used.
| tomcat.util.buf.StringCache.char.enabled |
If true, the String cache is enabled for
CharChunk.
If not specified, the default value of false will be used.
| tomcat.util.buf.StringCache.trainThreshold |
The number of times toString() must be called before the
cache is activated.
If not specified, the default value of 20000 will be used.
| tomcat.util.buf.StringCache.cacheSize |
The size of the String cache.
If not specified, the default value of 200 will be used.
| tomcat.util.buf.StringCache.maxStringSize |
The maximum length of String that will be cached.
If not specified, the default value of 128 will be used.
| org.apache.tomcat.util. http.FastHttpDateFormat.CACHE_SIZE |
The size of the cache to use parsed and formatted date value.
If not specified, the default value of 1000 will be used.
| org.apache.tomcat.util. net.NioSelectorShared |
If true, use a shared selector for servlet write/read.
If not specified, the default value of true will be used.
| org.apache.catalina.startup. EXIT_ON_INIT_FAILURE |
If true, the server will exit if an exception happens
during the server initialization phase.
If not specified, the default value of false will be used.
| org.apache.catalina.startup. RealmRuleSet.MAX_NESTED_REALM_LEVELS |
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.
| tomcat.util.http.parser.HttpParser. requestTargetAllow |
This system property is deprecated. Use the
relaxedPathChars and relaxedQueryChars
attributes of the Connector instead. These attributes permit a wider range
of characters to be configured as valid.
A string comprised of characters the server should allow even when they are not encoded.
These characters would normally result in a 400 status.
The acceptable characters for this property are: |, {
, and }
WARNING: Use of this option may expose the server to CVE-2016-6816.
If not specified, the default value of null will be used.
|
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