Apache Tomcat Configuration ReferenceThe HTTP Connector |  |
| Introduction |
HTTP Connector代表一个支持HTTP/1.1协定的Connector组件。它使Catalina在具有执行servlets和JSP页面能力之外，还能够作为独立的web服务器运作。这个组件的一个特殊的实例是在这个服务器上的一个特定的TCP端口数目上监听连接。一个或多个这样的Connectors(连接器)可以配置为一单个Service的一部分，每一个Connectors(连接器)转向它相关的Engine去处理请求和产生回应。
If you wish to configure the Connector that is used
for connections to web servers using the AJP protocol (such as the
mod_jk 1.2.x connector for Apache 1.3), see
here instead.
在服务器启动时间,这个Connector将产生许多处理请求的线程(根据配置的minSpareThreads属性的值)。每个进入的请求在这个请求其间需要一个线程。如果同时发生的多个请求被接收到，它们可以被当前可使用的处理请求的线程来处理，另外的线程将被产生直到所配置的最大数(就是maxThreads属性的值)。如果还有同时发生的多个请求被接收到，它们就在Connector所产生的server socket里面被堆积起来， 直到所配置的最大数为止(就是acceptCount属性的值)。其他更多的同时发生的请求将会收到"connection refused" 的错误信息，直到有资源能处理它们为止。
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| Attributes |
| Common Attributes |
Connector的所有实现支持下列属性：
| Attribute | Description |
|---|
allowTrace |
一个布林值，可以用来启用或取消TRACE HTTP方法。如果没有指定，这个属性被设置为false。
| emptySessionPath |
If set to true, all paths for session cookies will be set
to /. This can be useful for portlet specification implementations,
but will greatly affect performance if many applications are accessed on a given
server by the client.
If not specified, this attribute is set to false.
| enableLookups |
如果你想为了返回远程客户的实际主机名而调用request.getRemoteHost()方法来执行DNS查询，就把它设置为true。要跳过DNS查询并返回String形式的IP地址，就把它设置为false(这样可以提高性能)。在缺省情况下，DNS查询是可以启用的。
| maxPostSize |
The maximum size in bytes of the POST which will be handled by
the container FORM URL parameter parsing. The limit can be disabled by
setting this attribute to a value less than or equal to 0.
If not specified, this attribute is set to 2097152 (2 megabytes).
| maxSavePostSize |
The maximum size in bytes of the POST which will be saved/buffered by
the container during FORM or CLIENT-CERT authentication. For both types
of authentication, the POST will be saved/buffered before the user is
authenticated. For CLIENT-CERT authentication, the POST is buffered for
the duration of
the SSL handshake and the buffer emptied when the request
is processed. For FORM authentication the POST is
saved whilst the user
is re-directed to the login form and is retained until the user
successfully authenticates or the session associated with the
authentication request expires. The limit can be disabled by setting this
attribute to -1. Setting the attribute to
zero will disable the saving of
POST data during authentication
. If not
specified, this attribute is set
to
4096 (4 kilobytes).
| protocol |
This attribute value must be HTTP/1.1 to use the HTTP
handler, which is the default.
| proxyName |
If this Connector is being used in a proxy
configuration, configure this attribute to specify the server name
to be returned for calls to request.getServerName().
See Proxy Support for more
information.
| proxyPort |
If this Connector is being used in a proxy
configuration, configure this attribute to specify the server port
to be returned for calls to request.getServerPort().
See Proxy Support for more
information.
| redirectPort |
If this Connector is supporting non-SSL
requests, and a request is received for which a matching
<security-constraint> requires SSL transport,
Catalina will automatically redirect the request to the port
number specified here.
| scheme |
Set this attribute to the name of the protocol you wish to have
returned by calls to request.getScheme(). For
example, you would set this attribute to "https"
for an SSL Connector. The default value is "http".
See SSL Support for more information.
| secure |
Set this attribute to true if you wish to have
calls to request.isSecure() to return true
for requests received by this Connector (you would want this on an
SSL Connector). The default value is false.
| URIEncoding |
This specifies the character encoding used to decode the URI bytes,
after %xx decoding the URL. If not specified, ISO-8859-1 will be used.
| useBodyEncodingForURI |
This specifies if the encoding specified in contentType should be used
for URI query parameters, instead of using the URIEncoding. This
setting is present for compatibility with Tomcat 4.1.x, where the
encoding specified in the contentType, or explicitely set using
Request.setCharacterEncoding method was also used for the parameters from
the URL. The default value is false.
| useIPVHosts |
Set this attribute to true to cause Tomcat to use
the IP address that the request was recieved on to determine the Host
to send the request to. The default value is false.
| xpoweredBy |
Set this attribute to true to cause Tomcat to advertise
support for the Servlet specification using the header recommended in the
specification. The default value is false.
|
|
| Standard Implementation |
HTTP supports the following additional attributes (in addition to the
common attributes listed above):
| Attribute | Description |
|---|
acceptCount |
The maximum queue length for incoming connection requests when
all possible request processing threads are in use. Any requests
received when the queue is full will be refused. The default
value is 10.
| address |
对于具有不止一个IP地址的服务器来说,这个属性指定了哪一个地址将被用来在指定的端口监听。在缺省情况下，这个端口会被使用在所有与这个服务器相关的IP地址上。
| bufferSize |
The size (in bytes) of the buffer to be provided for input
streams created by this connector. By default, buffers of
2048 bytes will be provided.
| compressableMimeType |
The value is a comma separated list of MIME types for which HTTP
compression may be used.
The default value is text/html,text/xml,text/plain.
| compression |
The Connector may use HTTP/1.1 GZIP compression in
an attempt to save server bandwidth. The acceptable values for the
parameter is "off" (disable compression), "on" (allow compression, which
causes text data to be compressed), "force" (forces compression in all
cases), or a numerical integer value (which is equivalent to "on", but
specifies the minimum amount of data before the output is compressed). If
the content-length is not known and compression is set to "on" or more
aggressive, the output will also be compressed. If not specified, this
attribute is set to "off".
| connectionLinger |
The number of milliseconds during which the sockets used by this
Connector will linger when they are closed.
The default value is -1 (socket linger is disabled).
| connectionTimeout |
The number of milliseconds this Connector will wait,
after accepting a connection, for the request URI line to be
presented. The default value is 60000 (i.e. 60 seconds).
| disableUploadTimeout |
This flag allows the servlet container to use a different, longer
connection timeout while a servlet is being executed, which in the end
allows either the servlet a longer amount of time to complete its
execution, or a longer timeout during data upload. If not specified,
this attribute is set to "true".
| maxHttpHeaderSize |
The maximum size of the request and response HTTP header, specified
in bytes.
If not specified, this attribute is set to 4096 (4 KB).
| maxKeepAliveRequests |
The maximum number of HTTP requests which can be pipelined until
the connection is closed by the server. Setting this attribute to 1 will
disable HTTP/1.0 keep-alive, as well as HTTP/1.1 keep-alive and
pipelining. Setting this to -1 will allow an unlimited amount of
pipelined or keep-alive HTTP requests.
If not specified, this attribute is set to 100.
| maxSpareThreads |
The maximum number of unused request processing threads that
will be allowed to exist until the thread pool starts stopping the
unnecessary threads. The default value is 50.
| maxThreads |
The maximum number of request processing threads to be created
by this Connector, which therefore determines the
maximum number of simultaneous requests that can be handled. If
not specified, this attribute is set to 200.
| minSpareThreads |
The number of request processing threads that will be created
when this Connector is first started. The connector
will also make sure it has the specified number of idle processing
threads available. This attribute should be set to a value smaller
than that set for maxThreads. The default value is 4.
| noCompressionUserAgents |
The value is a comma separated list of regular expressions matching
user-agents of HTTP clients for which compression should not be used,
because these clients, although they do advertise support for the
feature, have a broken implementation.
The default value is an empty String (regexp matching disabled).
| port |
The TCP port number on which this Connector
will create a server socket and await incoming connections. Your
operating system will allow only one server application to listen
to a particular port number on a particular IP address.
| restrictedUserAgents |
The value is a comma separated list of regular expressions matching
user-agents of HTTP clients for which HTTP/1.1 or HTTP/1.0 keep alive
should not be used, even if the clients advertise support for these
features.
The default value is an empty String (regexp matching disabled).
| server |
The Server header for the http response.
Unless your paranoid, you won't need this feature.
| socketBuffer |
The size (in bytes) of the buffer to be provided for socket
output buffering. -1 can be specified to disable the use of a buffer.
By default, a buffers of 9000 bytes will be used.
| strategy |
The thread pooling strategy which will be used. The default strategy does
not use a master thread, but a more conventional strategy using a
master listener thread can be used by setting "ms" as this attribute's value.
The master strategy will work significantly better using the threadPriority
attribute, which will apply only to the thread which listens on the server socket.
This is set to lf by default.
| tcpNoDelay |
If set to true, the TCP_NO_DELAY option will be
set on the server socket, which improves performance under most
circumstances. This is set to true by default.
| threadPriority |
The priority of the request processing threads within the JVM.
The default value is java.lang.Thread#NORM_PRIORITY.
See the JavaDoc for the java.lang.Thread class for more details on
what this priority means.
|
|
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| Special Features |
| HTTP/1.1 and HTTP/1.0 Support |
This Connector supports all of the required features
of the HTTP/1.1 protocol, as described in RFC 2616, including persistent
connections, pipelining, expectations and chunked encoding. If the client
(typically a browser) supports only HTTP/1.0, the
Connector will gracefully fall back to supporting this
protocol as well. No special configuration is required to enable this
support. The Connector also supports HTTP/1.0
keep-alive.
RFC 2616 requires that HTTP servers always begin their responses with
the highest HTTP version that they claim to support. Therefore, this
Connector will always return HTTP/1.1 at
the beginning of its responses.
|
| Proxy Support |
The proxyName and proxyPort attributes can
be used when Tomcat is run behind a proxy server. These attributes
modify the values returned to web applications that call the
request.getServerName() and request.getServerPort()
methods, which are often used to construct absolute URLs for redirects.
Without configuring these attributes, the values returned would reflect
the server name and port on which the connection from the proxy server
was received, rather than the server name and port to whom the client
directed the original request.
For more information, see the
Proxy Support HOW-TO.
|
| SSL Support |
You can enable SSL support for a particular instance of this
Connector by setting the secure attribute to
true. In addition, you may need to configure the following
attributes:
| Attribute | Description |
|---|
algorithm |
The certificate encoding algorithm to be used. If not
specified, the default value is SunX509.
| clientAuth |
Set to true if you want the SSL stack to require a
valid certificate chain from the client before
accepting a connection.
Set to want if you
want the SSL stack to request a client
Certificate, but
not fail if one isn't presented. A false
value (which is the default) will not require a certificate chain
unless
the client requests a resource protected by a security
constraint
that uses CLIENT-CERT authentication. See the
SSL HowTo for an example.
| keystoreFile |
The pathname of the keystore file where you have stored the
server certificate to be loaded. By default, the pathname is
the file ".keystore" in the operating system home
directory of the user that is running Tomcat.
| keystorePass |
The password used to access the server certificate from the
specified keystore file. The default value is "changeit".
| keystoreType |
The type of keystore file to be used for the server certificate.
If not specified, the default value is "JKS".
| sslProtocol |
The version of the SSL protocol to use. If not specified,
the default is "TLS".
| ciphers |
A comma seperated list of the encryption ciphers that may be used.
If not specified, then any available cipher may be used.
|
For more information, see the
SSL Configuration HOW-TO.
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