| Links Top Level Elements Executors Connectors Containers Nested Components Cluster Elements Global Settings | Apache Tomcat Configuration ReferenceThe Valve Component| Introduction |  | 
  A Valve element represents a component that will be
  inserted into the request processing pipeline for the associated
  Catalina container (Engine,
  Host, or Context).
  Individual Valves have distinct processing capabilities, and are
  described individually below. 
    The description below uses the variable name $CATALINA_BASE to refer the
    base directory against which most relative paths are resolved. If you have
    not configured Tomcat 6 for multiple instances by setting a CATALINA_BASE
    directory, then $CATALINA_BASE will be set to the value of $CATALINA_HOME,
    the directory into which you have installed Tomcat 6. | 
 | Access Log Valve |  | 
  | Introduction |  | 
    The Access Log Valve creates log files in the same
    format as those created by standard web servers.  These logs can later
    be analyzed by standard log analysis tools to track page hit counts,
    user session activity, and so on.  The files produces by this Valveare rolled over nightly at midnight.  ThisValvemay be associated with any Catalina container (Context,Host, orEngine), and
    will record ALL requests processed by that container. | 
 | Attributes |  | 
    The Access Log Valve supports the following
    configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.valves.AccessLogValve to use the
        default access log valve. |  | directory | Absolute or relative pathname of a directory in which log files
        created by this valve will be placed.  If a relative path is
        specified, it is interpreted as relative to $CATALINA_BASE.  If
        no directory attribute is specified, the default value is "logs"
        (relative to $CATALINA_BASE). |  | pattern | A formatting layout identifying the various information fields
        from the request and response to be logged, or the word
        commonorcombinedto select a
        standard format.  See below for more information on configuring
        this attribute. Note that the optimized access does only supportcommonandcombinedas the value for this
        attribute. |  | prefix | The prefix added to the start of each log file's name.  If not
        specified, the default value is "access_log.".  To specify no prefix,
        use a zero-length string. |  | resolveHosts | Set to trueto convert the IP address of the remote
        host into the corresponding host name via a DNS lookup.  Set tofalseto skip this lookup, and report the remote IP
        address instead. |  | suffix | The suffix added to the end of each log file's name.  If not
        specified, the default value is "".  To specify no suffix,
        use a zero-length string. |  | rotatable | Flag to determine if log rotation should occur.
           If set to false, then this file is never rotated and
           fileDateFormat is ignored. Use with caution!
           Default value: true
         |  | condition | Turns on conditional logging. If set, requests will be
           logged only if ServletRequest.getAttribute() is
           null. For example, if this value is set to
           junk, then a particular request will only be logged
           if ServletRequest.getAttribute("junk") == null.
           The use of Filters is an easy way to set/unset the attribute
           in the ServletRequest on many different requests.
         |  | fileDateFormat | Allows a customized date format in the access log file name.
           The date format also decides how often the file is rotated.
           If you wish to rotate every hour, then set this value
           to: yyyy-MM-dd.HH
         |  | buffered | Flag to determine if logging will be buffered.
           If set to false, then access logging will be written after each 
           request. Default value: true
         | 
 Values for the patternattribute are made up of literal
    text strings, combined with pattern identifiers prefixed by the "%"
    character to cause replacement by the corresponding variable value from
    the current request and response.  The following pattern codes are
    supported: 
    %a - Remote IP address%A - Local IP address%b - Bytes sent, excluding HTTP headers, or '-' if zero%B - Bytes sent, excluding HTTP headers%h - Remote host name (or IP address if
        resolveHostsis false)%H - Request protocol%l - Remote logical username from identd (always returns
        '-')%m - Request method (GET, POST, etc.)%p - Local port on which this request was received%q - Query string (prepended with a '?' if it exists)%r - First line of the request (method and request URI)%s - HTTP status code of the response%S - User session ID%t - Date and time, in Common Log Format%u - Remote user that was authenticated (if any), else '-'%U - Requested URL path%v - Local server name%D - Time taken to process the request, in millis%T - Time taken to process the request, in seconds%I - current request thread name (can compare later with stacktraces) 
    There is also support to write information from the cookie, incoming
    header, the Session or something else in the ServletRequest.
    It is modeled after the apache syntax:
     
    %{xxx}ifor incoming headers%{xxx}ofor outgoing response headers%{xxx}cfor a specific cookie%{xxx}rxxx is an attribute in the ServletRequest%{xxx}sxxx is an attribute in the HttpSession The shorthand pattern name common(which is also the
    default) corresponds to '%h %l %u %t "%r" %s %b'. The shorthand pattern name combinedappends the
    values of theRefererandUser-Agentheaders,
    each in double quotes, to thecommonpattern
    described in the previous paragraph. | 
 | 
 | Remote Address Filter |  | 
  | Introduction |  | 
    The Remote Address Filter allows you to compare the
    IP address of the client that submitted this request against one or more
    regular expressions, and either allow the request to continue
    or refuse to process the request from this client.  A Remote Address
    Filter can be associated with any Catalina container
    (Engine, Host, or
    Context), and must accept any request
    presented to this container for processing before it will be passed on. The syntax for regular expressions is different than that for
    'standard' wildcard matching. Tomcat uses the java.util.regexpackage. Please consult the Java documentation for details of the
    expressions supported. | 
 | Attributes |  | 
    The Remote Address Filter supports the following
    configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.valves.RemoteAddrValve. |  | allow | A comma-separated list of regular expression patterns
        that the remote client's IP address is compared to.  If this attribute
        is specified, the remote address MUST match for this request to be
        accepted.  If this attribute is not specified, all requests will be
        accepted UNLESS the remote address matches a denypattern. |  | deny | A comma-separated list of regular expression patterns
        that the remote client's IP address is compared to.  If this attribute
        is specified, the remote address MUST NOT match for this request to be
        accepted.  If this attribute is not specified, request acceptance is
        governed solely by the acceptattribute. | 
 | 
 | 
 | Remote Host Filter |  | 
  | Introduction |  | 
    The Remote Host Filter allows you to compare the
    hostname of the client that submitted this request against one or more
    regular expressions, and either allow the request to continue
    or refuse to process the request from this client.  A Remote Host
    Filter can be associated with any Catalina container
    (Engine, Host, or
    Context), and must accept any request
    presented to this container for processing before it will be passed on. The syntax for regular expressions is different than that for
    'standard' wildcard matching. Tomcat uses the java.util.regexpackage. Please consult the Java documentation for details of the
    expressions supported. | 
 | Attributes |  | 
    The Remote Host Filter supports the following
    configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.valves.RemoteHostValve. |  | allow | A comma-separated list of regular expression patterns
        that the remote client's hostname is compared to.  If this attribute
        is specified, the remote hostname MUST match for this request to be
        accepted.  If this attribute is not specified, all requests will be
        accepted UNLESS the remote hostname matches a denypattern. |  | deny | A comma-separated list of regular expression patterns
        that the remote client's hostname is compared to.  If this attribute
        is specified, the remote hostname MUST NOT match for this request to be
        accepted.  If this attribute is not specified, request acceptance is
        governed solely by the acceptattribute. | 
 | 
 | 
 | Request Dumper Valve |  | 
  | Introduction |  | 
    The Request Dumper Valve is a useful tool in debugging
    interactions with a client application (or browser) that is sending
    HTTP requests to your Tomcat-based server.  When configured, it causes
    details about each request processed by its associated Engine,Host, orContextto be logged according to 
    the logging configuration for that container. WARNING: Using this valve has side-effects.  The
    output from this valve includes any parameters included with the request.
    The parameters will be decoded using the default platform encoding. Any
    subsequent calls to request.setCharacterEncoding()within
    the web application will have no effect. | 
 | Attributes |  | 
    The Request Dumper Valve supports the following
    configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.valves.RequestDumperValve. | 
 | 
 | 
 | Single Sign On Valve |  | 
  | Introduction |  | 
    The Single Sign On Vale is utilized when you wish to give users
    the ability to sign on to any one of the web applications associated with
    your virtual host, and then have their identity recognized by all other
    web applications on the same virtual host. See the Single Sign On special
    feature on the Host element for more information. | 
 | Attributes |  | 
    The Single Sign On Valve supports the following
    configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.authenticator.SingleSignOn. |  | requireReauthentication | Default false. Flag to determine whether each request needs to be 
        reauthenticated to the security Realm. If "true", this
        Valve uses cached security credentials (username and password) to
        reauthenticate to the Realm each request associated 
        with an SSO session.  If "false", the Valve can itself authenticate 
        requests based on the presence of a valid SSO cookie, without 
        rechecking with the Realm. |  | cookieDomain | Sets the host domain to be used for sso cookies. | 
 | 
 | 
 | Basic Authenticator Valve |  | 
  | Introduction |  | 
    The Basic Authenticator Valve is automatically added to
    any Context that is configured to use BASIC
    authentication. If any non-default settings are required, the valve may be configured
    within Context element with the required
    values. | 
 | Attributes |  | 
    The Basic Authenticator Valve supports the following
    configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.authenticator.BasicAuthenticator. |  | changeSessionIdOnAuthentication | Controls if the session ID is changed if a session exists at the
        point where users are authenticated. This is to prevent session fixation
        attacks. If not set, the default value of truewill be
        used. |  | disableProxyCaching | Controls the caching of pages that are protected by security
        constraints. Setting this to falsemay help work around
        caching issues in some browsers but will also cause secured pages to be
        cached by proxies which will almost certainly be a security issue.securePagesWithPragmaoffers an alternative, secure,
        workaround for browser caching issues. If not set, the default value oftruewill be used. |  | securePagesWithPragma | Controls the caching of pages that are protected by security
        constraints. Setting this to falsemay help work around
        caching issues in some browsers by usingCache-Control: privaterather than the default ofPragma: No-cacheandCache-control: No-cache.
        If not set, the default value oftruewill be used. | 
 | 
 | 
 | Digest Authenticator Valve |  | 
  | Introduction |  | 
    The Digest Authenticator Valve is automatically added to
    any Context that is configured to use DIGEST
    authentication. If any non-default settings are required, the valve may be configured
    within Context element with the required
    values. | 
 | Attributes |  | 
    The Digest Authenticator Valve supports the following
    configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.authenticator.DigestAuthenticator. |  | changeSessionIdOnAuthentication | Controls if the session ID is changed if a session exists at the
        point where users are authenticated. This is to prevent session fixation
        attacks. If not set, the default value of truewill be
        used. |  | disableProxyCaching | Controls the caching of pages that are protected by security
        constraints. Setting this to falsemay help work around
        caching issues in some browsers but will also cause secured pages to be
        cached by proxies which will almost certainly be a security issue.securePagesWithPragmaoffers an alternative, secure,
        workaround for browser caching issues. If not set, the default value oftruewill be used. |  | securePagesWithPragma | Controls the caching of pages that are protected by security
        constraints. Setting this to falsemay help work around
        caching issues in some browsers by usingCache-Control: privaterather than the default ofPragma: No-cacheandCache-control: No-cache.
        If not set, the default value oftruewill be used. | 
 | 
 | 
 | Form Authenticator Valve |  | 
  | Introduction |  | 
    The Form Authenticator Valve is automatically added to
    any Context that is configured to use FORM
    authentication. If any non-default settings are required, the valve may be configured
    within Context element with the required
    values. | 
 | Attributes |  | 
    The Form Authenticator Valve supports the following
    configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.authenticator.FormAuthenticator. |  | changeSessionIdOnAuthentication | Controls if the session ID is changed if a session exists at the
        point where users are authenticated. This is to prevent session fixation
        attacks. If not set, the default value of truewill be
        used. |  | characterEncoding | Character encoding to use to read the username and password parameters
        from the request. If not set, the encoding of the request body will be
        used. |  | disableProxyCaching | Controls the caching of pages that are protected by security
        constraints. Setting this to falsemay help work around
        caching issues in some browsers but will also cause secured pages to be
        cached by proxies which will almost certainly be a security issue.securePagesWithPragmaoffers an alternative, secure,
        workaround for browser caching issues. If not set, the default value oftruewill be used. |  | securePagesWithPragma | Controls the caching of pages that are protected by security
        constraints. Setting this to falsemay help work around
        caching issues in some browsers by usingCache-Control: privaterather than the default ofPragma: No-cacheandCache-control: No-cache.
        If not set, the default value oftruewill be used. | 
 | 
 | 
 | SSL Authenticator Valve |  | 
  | Introduction |  | 
    The SSL Authenticator Valve is automatically added to
    any Context that is configured to use SSL
    authentication. If any non-default settings are required, the valve may be configured
    within Context element with the required
    values. | 
 | Attributes |  | 
    The SSL Authenticator Valve supports the following
    configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.authenticator.SSLAuthenticator. |  | changeSessionIdOnAuthentication | Controls if the session ID is changed if a session exists at the
        point where users are authenticated. This is to prevent session fixation
        attacks. If not set, the default value of truewill be
        used. |  | disableProxyCaching | Controls the caching of pages that are protected by security
        constraints. Setting this to falsemay help work around
        caching issues in some browsers but will also cause secured pages to be
        cached by proxies which will almost certainly be a security issue.securePagesWithPragmaoffers an alternative, secure,
        workaround for browser caching issues. If not set, the default value oftruewill be used. |  | securePagesWithPragma | Controls the caching of pages that are protected by security
        constraints. Setting this to falsemay help work around
        caching issues in some browsers by usingCache-Control: privaterather than the default ofPragma: No-cacheandCache-control: No-cache.
        If not set, the default value oftruewill be used. | 
 | 
 | 
 | WebDAV Fix Valve |  | 
  | Introduction |  | 
    Microsoft operating systems have two WebDAV clients. One is used with
    port 80, the other is used for all other ports. The implementation used with
    port 80 does not adhere to the WebDAV specification and fails when trying to
    communicate with the Tomcat WebDAV Servlet. This valve provides a fix for
    this by forcing the use of the WebDAV implementation that works, even when
    connecting via port 80. This Valve may be used at the Engine,HostorContextlevel as required. Normally, this Valve would be used
    at theContextlevel. | 
 | Attributes |  | 
    The WebDAV Fix Valve supports the following
    configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.valves.WebdavFixValve. | 
 | 
 | 
 | Remote IP Valve |  | 
  | Introduction |  | 
  
    Tomcat port of
    mod_remoteip,
    this valve replaces the apparent client remote IP address and hostname for
    the request with the IP address list presented by a proxy or a load balancer
    via a request headers (e.g. "X-Forwarded-For"). Another feature of this valve is to replace the apparent scheme
    (http/https), server port and request.securewith the scheme presented 
    by a proxy or a load balancer via a request header 
    (e.g. "X-Forwarded-Proto"). This Valve may be used at the Engine,HostorContextlevel as required. Normally, this Valve would be used
    at theEnginelevel. If used in conjunction with Remote Address/Host valves then this valve
    should be defined first to ensure that the correct client IP address is
    presented to the Remote Address/Host valves. | 
 | Attributes |  | 
    The Remote IP Valve supports the
    following configuration attributes: | Attribute | Description | 
|---|
 | className | Java class name of the implementation to use.  This MUST be set to
        org.apache.catalina.valves.RemoteIpValve. |  | remoteIPHeader | Name of the HTTP Header read by this valve that holds the list of
        traversed IP addresses starting from the requesting client. If not
        specified, the default of x-forwarded-foris used. |  | internalProxies | List of internal proxies' IP addresses as comma separated regular
        expressions. If they appear in the remoteIpHeader
        value, they will be trusted and will not appear in the
        proxiesHeader value. If not specified the default value
        of 10\.\d{1,3}\.\d{1,3}\.\d{1,3}, 192\.168\.\d{1,3}\.\d{1,3},
        169\.254\.\d{1,3}\.\d{1,3}, 127\.\d{1,3}\.\d{1,3}\.\d{1,3}will
        be used. |  | proxiesHeader | Name of the HTTP header created by this valve to hold the list of
        proxies that have been processed in the incoming
        remoteIpHeader. If not specified, the default of
        x-forwarded-byis used. |  | trustedProxies | List of trusted proxies' IP addresses as comma separated regular
        expressions. If they appear in the remoteIpHeader
        value, they will be trusted and will appear in the
        proxiesHeader value. If not specified, no proxies will
        be trusted. |  | protocolHeader | Name of the HTTP Header read by this valve that holds the protocol
        used by the client to connect to the proxy. If not specified, the
        default of nullis used. |  | protocolHeaderHttpsValue | Value of the protocolHeader to indicate that it is
        an HTTPS request. If not specified, the default of httpsis
        used. |  | httpServerPort | Value returned by ServletRequest.getServerPort()when the protocolHeader indicateshttpprotocol. If not specified, the default of80is
        used. |  | httpsServerPort | Value returned by ServletRequest.getServerPort()when the protocolHeader indicateshttpsprotocol. If not specified, the default of443is
        used. | 
 | 
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