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| <ul><li><a href="#Introduction">Introduction</a></li><li><a href="#Attributes">Attributes</a><ol><li><a href="#Common_Attributes">Common Attributes</a></li><li><a href="#Standard_Implementations">Standard Implementations</a></li><li><a href="#Java_TCP_socket_attributes">Java TCP socket attributes</a></li><li><a href="#NIO_specific_configuration">NIO specific configuration</a></li><li><a href="#APR/native_specific_configuration">APR/native specific configuration</a></li></ol></li><li><a href="#Nested_Components">Nested Components</a></li><li><a href="#Special_Features">Special Features</a><ol><li><a href="#Proxy_Support">Proxy Support</a></li><li><a href="#Connector_Comparison">Connector Comparison</a></li></ol></li></ul> | |
| </blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Introduction"><strong>Introduction</strong></a></font></td></tr><tr><td><blockquote> | |
| <p>The <strong>AJP Connector</strong> element represents a | |
| <strong>Connector</strong> component that communicates with a web | |
| connector via the <code>AJP</code> protocol. This is used for cases | |
| where you wish to invisibly integrate Tomcat into an existing (or new) | |
| Apache installation, and you want Apache to handle the static content | |
| contained in the web application, and/or utilize Apache's SSL | |
| processing.</p> | |
| <p>This connector supports load balancing when used in conjunction with | |
| the <code>jvmRoute</code> attribute of the | |
| <a href="engine.html">Engine</a>.</p> | |
| <p>The native connectors supported with this Tomcat release are:</p> | |
| <ul> | |
| <li>JK 1.2.x with any of the supported servers. See | |
| <a href="http://tomcat.apache.org/connectors-doc/">the JK docs</a> | |
| for details.</li> | |
| <li>mod_proxy on Apache httpd 2.x (included by default in Apache HTTP | |
| Server 2.2), with AJP enabled: see | |
| <a href="http://httpd.apache.org/docs/2.2/mod/mod_proxy_ajp.html">the | |
| httpd docs</a> for details.</li> | |
| </ul> | |
| <p><b>Other native connectors supporting AJP may work, but are no longer | |
| supported.</b></p> | |
| </blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Attributes"><strong>Attributes</strong></a></font></td></tr><tr><td><blockquote> | |
| <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Common Attributes"><!--()--></a><a name="Common_Attributes"><strong>Common Attributes</strong></a></font></td></tr><tr><td><blockquote> | |
| <p>All implementations of <strong>Connector</strong> | |
| support the following attributes:</p> | |
| <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code class="attributeName">ajpFlush</code></td><td align="left" valign="center"> | |
| <p>A boolean value which can be used to enable or disable sending | |
| AJP flush messages to the fronting proxy whenever an explicit | |
| flush happens. The default value is <code>true</code>.<br> | |
| An AJP flush message is a SEND_BODY_CHUNK packet with no body content. | |
| Proxy implementations like mod_jk or mod_proxy_ajp will flush the | |
| data buffered in the web server to the client when they receive | |
| such a packet. Setting this to <code>false</code> can reduce | |
| AJP packet traffic but might delay sending packets to the client. | |
| At the end of the response, AJP does always flush to the client.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">allowTrace</code></td><td align="left" valign="center"> | |
| <p>A boolean value which can be used to enable or disable the TRACE | |
| HTTP method. If not specified, this attribute is set to false.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">asyncTimeout</code></td><td align="left" valign="center"> | |
| <p>The default timeout for asynchronous requests in milliseconds. If not | |
| specified, this attribute is set to 10000 (10 seconds).</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">enableLookups</code></td><td align="left" valign="center"> | |
| <p>Set to <code>true</code> if you want calls to | |
| <code>request.getRemoteHost()</code> to perform DNS lookups in | |
| order to return the actual host name of the remote client. Set | |
| to <code>false</code> to skip the DNS lookup and return the IP | |
| address in String form instead (thereby improving performance). | |
| By default, DNS lookups are disabled.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxHeaderCount</code></td><td align="left" valign="center"> | |
| <p>The maximum number of headers in a request that are allowed by the | |
| container. A request that contains more headers than the specified limit | |
| will be rejected. A value of less than 0 means no limit. | |
| If not specified, a default of 100 is used.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxParameterCount</code></td><td align="left" valign="center"> | |
| <p>The maximum number of parameter and value pairs (GET plus POST) which | |
| will be automatically parsed by the container. Parameter and value pairs | |
| beyond this limit will be ignored. A value of less than 0 means no limit. | |
| If not specified, a default of 10000 is used. Note that | |
| <code>FailedRequestFilter</code> <a href="filter.html">filter</a> can be | |
| used to reject requests that hit the limit.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxPostSize</code></td><td align="left" valign="center"> | |
| <p>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 zero. If not specified, this | |
| attribute is set to 2097152 (2 megabytes). Note that the | |
| <a href="filter.html#Failed_Request_Filter"><code>FailedRequestFilter</code></a> | |
| can be used to reject requests that exceed this limit.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxSavePostSize</code></td><td align="left" valign="center"> | |
| <p>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).</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">parseBodyMethods</code></td><td align="left" valign="center"> | |
| <p>A comma-separated list of HTTP methods for which request | |
| bodies will be parsed for request parameters identically | |
| to POST. This is useful in RESTful applications that want to | |
| support POST-style semantics for PUT requests. | |
| Note that any setting other than <code>POST</code> causes Tomcat | |
| to behave in a way that goes against the intent of the servlet | |
| specification. | |
| The HTTP method TRACE is specifically forbidden here in accordance | |
| with the HTTP specification. | |
| The default is <code>POST</code></p> | |
| </td></tr><tr><td align="left" valign="center"><strong><code class="attributeName">port</code></strong></td><td align="left" valign="center"> | |
| <p>The TCP port number on which this <strong>Connector</strong> | |
| 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. If the special | |
| value of 0 (zero) is used, then Tomcat will select a free port at random | |
| to use for this connector. This is typically only useful in embedded and | |
| testing applications.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">protocol</code></td><td align="left" valign="center"> | |
| <p>Sets the protocol to handle incoming traffic. To configure an AJP | |
| connector this must be specified. If no value for protocol is provided, | |
| an <a href="http.html">HTTP connector</a> rather than an AJP connector | |
| will be configured.<br> | |
| The standard protocol value for an AJP connector is <code>AJP/1.3</code> | |
| which uses an auto-switching mechanism to select either a Java based | |
| connector or an APR/native based connector. If the | |
| <code>PATH</code> (Windows) or <code>LD_LIBRARY_PATH</code> (on most unix | |
| systems) environment variables contain the Tomcat native library, the | |
| native/APR connector will be used. If the native library cannot be | |
| found, the Java BIO based connector will be used.<br> | |
| To use an explicit protocol rather than rely on the auto-switching | |
| mechanism described above, the following values may be used:<br> | |
| <code>org.apache.coyote.ajp.AjpProtocol</code> | |
| - blocking Java connector<br> | |
| <code>org.apache.coyote.ajp.AjpNioProtocol</code> | |
| - non blocking Java connector.<br> | |
| <code>org.apache.coyote.ajp.AjpAprProtocol</code> | |
| - the APR/native connector.<br> | |
| Custom implementations may also be used.<br> | |
| Take a look at our <a href="#Connector_Comparison">Connector | |
| Comparison</a> chart. | |
| </p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">proxyName</code></td><td align="left" valign="center"> | |
| <p>If this <strong>Connector</strong> is being used in a proxy | |
| configuration, configure this attribute to specify the server name | |
| to be returned for calls to <code>request.getServerName()</code>. | |
| See <a href="#Proxy_Support">Proxy Support</a> for more | |
| information.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">proxyPort</code></td><td align="left" valign="center"> | |
| <p>If this <strong>Connector</strong> is being used in a proxy | |
| configuration, configure this attribute to specify the server port | |
| to be returned for calls to <code>request.getServerPort()</code>. | |
| See <a href="#Proxy_Support">Proxy Support</a> for more | |
| information.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">redirectPort</code></td><td align="left" valign="center"> | |
| <p>If this <strong>Connector</strong> is supporting non-SSL | |
| requests, and a request is received for which a matching | |
| <code><security-constraint></code> requires SSL transport, | |
| Catalina will automatically redirect the request to the port | |
| number specified here.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">scheme</code></td><td align="left" valign="center"> | |
| <p>Set this attribute to the name of the protocol you wish to have | |
| returned by calls to <code>request.getScheme()</code>. For | |
| example, you would set this attribute to "<code>https</code>" | |
| for an SSL Connector. The default value is "<code>http</code>". | |
| </p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">secure</code></td><td align="left" valign="center"> | |
| <p>Set this attribute to <code>true</code> if you wish to have | |
| calls to <code>request.isSecure()</code> to return <code>true</code> | |
| for requests received by this Connector. You would want this on an | |
| SSL Connector or a non SSL connector that is receiving data from a | |
| SSL accelerator, like a crypto card, a SSL appliance or even a webserver. | |
| The default value is <code>false</code>.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">URIEncoding</code></td><td align="left" valign="center"> | |
| <p>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. | |
| </p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">useBodyEncodingForURI</code></td><td align="left" valign="center"> | |
| <p>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 explicitly set using | |
| Request.setCharacterEncoding method was also used for the parameters from | |
| the URL. The default value is <code>false</code>. | |
| </p> | |
| <p><em>Notes:</em> See notes on this attribute in | |
| <a href="http.html">HTTP Connector</a> documentation.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">useIPVHosts</code></td><td align="left" valign="center"> | |
| <p>Set this attribute to <code>true</code> to cause Tomcat to use | |
| the IP address passed by the native web server to determine the Host | |
| to send the request to. The default value is <code>false</code>.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">xpoweredBy</code></td><td align="left" valign="center"> | |
| <p>Set this attribute to <code>true</code> to cause Tomcat to advertise | |
| support for the Servlet specification using the header recommended in the | |
| specification. The default value is <code>false</code>.</p> | |
| </td></tr></table> | |
| </blockquote></td></tr></table> | |
| <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Standard Implementations"><!--()--></a><a name="Standard_Implementations"><strong>Standard Implementations</strong></a></font></td></tr><tr><td><blockquote> | |
| <p>To use AJP, you must specify the protocol attribute (see above).</p> | |
| <p>The standard AJP connectors (BIO, NIO and APR/native) all support the | |
| following attributes in addition to the common Connector attributes listed | |
| above.</p> | |
| <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code class="attributeName">acceptCount</code></td><td align="left" valign="center"> | |
| <p>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 100.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">acceptorThreadCount</code></td><td align="left" valign="center"> | |
| <p>The number of threads to be used to accept connections. Increase this | |
| value on a multi CPU machine, although you would never really need more | |
| than <code>2</code>. Also, with a lot of non keep alive connections, you | |
| might want to increase this value as well. Default value is | |
| <code>1</code>.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">acceptorThreadPriority</code></td><td align="left" valign="center"> | |
| <p>The priority of the acceptor threads. The threads used to accept | |
| new connections. The default value is <code>5</code> (the value of the | |
| <code>java.lang.Thread.NORM_PRIORITY</code> constant). See the JavaDoc | |
| for the <code>java.lang.Thread</code> class for more details on what | |
| this priority means.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">address</code></td><td align="left" valign="center"> | |
| <p>For servers with more than one IP address, this attribute | |
| specifies which address will be used for listening on the specified | |
| port. By default, this port will be used on all IP addresses | |
| associated with the server. A value of <code>127.0.0.1</code> | |
| indicates that the Connector will only listen on the loopback | |
| interface.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">bindOnInit</code></td><td align="left" valign="center"> | |
| <p>Controls when the socket used by the connector is bound. By default it | |
| is bound when the connector is initiated and unbound when the connector is | |
| destroyed. If set to <code>false</code>, the socket will be bound when the | |
| connector is started and unbound when it is stopped.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">clientCertProvider</code></td><td align="left" valign="center"> | |
| <p>When client certificate information is presented in a form other than | |
| instances of <code>java.security.cert.X509Certificate</code> it needs to | |
| be converted before it can be used and this property controls which JSSE | |
| provider is used to perform the conversion. For example it is used with | |
| the AJP connectors, the <a href="http.html">HTTP APR connector</a> and | |
| with the <a href="valve.html#SSL_Authenticator_Valve"> | |
| org.apache.catalina.valves.SSLValve</a>.If not specified, the default | |
| provider will be used.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">connectionLinger</code></td><td align="left" valign="center"> | |
| <p>The number of seconds during which the sockets used by this | |
| <strong>Connector</strong> will linger when they are closed. The default | |
| value is <code>-1</code> which disables socket linger.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">connectionTimeout</code></td><td align="left" valign="center"> | |
| <p>The number of milliseconds this <strong>Connector</strong> will wait, | |
| after accepting a connection, for the request URI line to be | |
| presented. The default value for AJP protocol connectors | |
| is <code>-1</code> (i.e. infinite).</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">executor</code></td><td align="left" valign="center"> | |
| <p>A reference to the name in an <a href="executor.html">Executor</a> | |
| element. If this attribute is set, and the named executor exists, the | |
| connector will use the executor, and all the other thread attributes will | |
| be ignored. Note that if a shared executor is not specified for a | |
| connector then the connector will use a private, internal executor to | |
| provide the thread pool.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">executorTerminationTimeoutMillis</code></td><td align="left" valign="center"> | |
| <p>The time that the private internal executor will wait for request | |
| processing threads to terminate before continuing with the process of | |
| stopping the connector. If not set, the default is <code>0</code> (zero) | |
| for the BIO connector and <code>5000</code> (5 seconds) for the NIO and | |
| APR/native connectors.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">keepAliveTimeout</code></td><td align="left" valign="center"> | |
| <p>The number of milliseconds this <strong>Connector</strong> will wait for | |
| another AJP request before closing the connection. | |
| The default value is to use the value that has been set for the | |
| connectionTimeout attribute.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxConnections</code></td><td align="left" valign="center"> | |
| <p>The maximum number of connections that the server will accept and | |
| process at any given time. When this number has been reached, the server | |
| will accept, but not process, one further connection. This additional | |
| connection be blocked until the number of connections being processed | |
| falls below <strong>maxConnections</strong> at which point the server will | |
| start accepting and processing new connections again. Note that once the | |
| limit has been reached, the operating system may still accept connections | |
| based on the <code>acceptCount</code> setting. The default value varies by | |
| connector type. For BIO the default is the value of | |
| <strong>maxThreads</strong> unless an <a href="executor.html">Executor</a> | |
| is used in which case the default will be the value of maxThreads from the | |
| executor. For NIO the default is <code>10000</code>. | |
| For APR/native, the default is <code>8192</code>.</p> | |
| <p>Note that for APR/native on Windows, the configured value will be | |
| reduced to the highest multiple of 1024 that is less than or equal to | |
| maxConnections. This is done for performance reasons.<br> | |
| If set to a value of -1, the maxConnections feature is disabled | |
| and connections are not counted.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxCookieCount</code></td><td align="left" valign="center"> | |
| <p>The maximum number of cookies that are permitted for a request. A value | |
| of less than zero means no limit. If not specified, a default value of 200 | |
| will be used.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxThreads</code></td><td align="left" valign="center"> | |
| <p>The maximum number of request processing threads to be created | |
| by this <strong>Connector</strong>, which therefore determines the | |
| maximum number of simultaneous requests that can be handled. If | |
| not specified, this attribute is set to 200. If an executor is associated | |
| with this connector, this attribute is ignored as the connector will | |
| execute tasks using the executor rather than an internal thread pool. Note | |
| that if an executor is configured any value set for this attribute will be | |
| recorded correctly but it will be reported (e.g. via JMX) as | |
| <code>-1</code> to make clear that it is not used.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">minSpareThreads</code></td><td align="left" valign="center"> | |
| <p>The minimum number of threads always kept running. If not specified, | |
| the default of <code>10</code> is used. If an executor is associated | |
| with this connector, this attribute is ignored as the connector will | |
| execute tasks using the executor rather than an internal thread pool. Note | |
| that if an executor is configured any value set for this attribute will be | |
| recorded correctly but it will be reported (e.g. via JMX) as | |
| <code>-1</code> to make clear that it is not used.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">packetSize</code></td><td align="left" valign="center"> | |
| <p>This attribute sets the maximum AJP packet size in Bytes. The maximum | |
| value is 65536. It should be the same as the <code>max_packet_size</code> | |
| directive configured for mod_jk. Normally it is not necessary to change | |
| the maximum packet size. Problems with the default value have been | |
| reported when sending certificates or certificate chains. The default | |
| value is 8192. If set to less than 8192 then the setting will ignored and | |
| the default value of 8192 used.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">processorCache</code></td><td align="left" valign="center"> | |
| <p>The protocol handler caches Processor objects to speed up performance. | |
| This setting dictates how many of these objects get cached. | |
| <code>-1</code> means unlimited, default is <code>200</code>. If not using | |
| Servlet 3.0 asynchronous processing, a good default is to use the same as | |
| the maxThreads setting. If using Servlet 3.0 asynchronous processing, a | |
| good default is to use the larger of maxThreads and the maximum number of | |
| expected concurrent requests (synchronous and asynchronous).</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">requiredSecret</code></td><td align="left" valign="center"> | |
| <p>Only requests from workers with this secret keyword will be accepted. | |
| </p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">tcpNoDelay</code></td><td align="left" valign="center"> | |
| <p>If set to <code>true</code>, the TCP_NO_DELAY option will be | |
| set on the server socket, which improves performance under most | |
| circumstances. This is set to <code>true</code> by default.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">threadPriority</code></td><td align="left" valign="center"> | |
| <p>The priority of the request processing threads within the JVM. | |
| The default value is <code>5</code> (the value of the | |
| <code>java.lang.Thread.NORM_PRIORITY</code> constant). See the JavaDoc | |
| for the <code>java.lang.Thread</code> class for more details on what | |
| this priority means.If an executor is associated | |
| with this connector, this attribute is ignored as the connector will | |
| execute tasks using the executor rather than an internal thread pool. Note | |
| that if an executor is configured any value set for this attribute will be | |
| recorded correctly but it will be reported (e.g. via JMX) as | |
| <code>-1</code> to make clear that it is not used.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">tomcatAuthentication</code></td><td align="left" valign="center"> | |
| <p>If set to <code>true</code>, the authentication will be done in Tomcat. | |
| Otherwise, the authenticated principal will be propagated from the native | |
| webserver and used for authorization in Tomcat. Note that this principal | |
| will have no roles associated with it. | |
| The default value is <code>true</code>. If | |
| <code>tomcatAuthorization</code> is set to <code>true</code> this | |
| attribute has no effect.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">tomcatAuthorization</code></td><td align="left" valign="center"> | |
| <p>If set to <code>true</code>, the authenticated principal will be | |
| propagated from the native webserver and considered already authenticated | |
| in Tomcat. If the web application has one or more security constraints, | |
| authorization will then be performed by Tomcat and roles assigned to the | |
| authenticated principal. If the appropriate Tomcat Realm for the request | |
| does not recognise the provided user name, a Principal will be still be | |
| created but it will have no roles. The default value is | |
| <code>false</code>.</p> | |
| </td></tr></table> | |
| </blockquote></td></tr></table> | |
| <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Java TCP socket attributes"><!--()--></a><a name="Java_TCP_socket_attributes"><strong>Java TCP socket attributes</strong></a></font></td></tr><tr><td><blockquote> | |
| <p>The BIO and NIO implementation support the following Java TCP socket | |
| attributes in addition to the common Connector and HTTP attributes listed | |
| above.</p> | |
| <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code class="attributeName">socket.rxBufSize</code></td><td align="left" valign="center"> | |
| <p>(int)The socket receive buffer (SO_RCVBUF) size in bytes. JVM default | |
| used if not set.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.txBufSize</code></td><td align="left" valign="center"> | |
| <p>(int)The socket send buffer (SO_SNDBUF) size in bytes. JVM default | |
| used if not set.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.tcpNoDelay</code></td><td align="left" valign="center"> | |
| <p>(bool)This is equivalent to standard attribute | |
| <strong>tcpNoDelay</strong>.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.soKeepAlive</code></td><td align="left" valign="center"> | |
| <p>(bool)Boolean value for the socket's keep alive setting | |
| (SO_KEEPALIVE). JVM default used if not set.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.ooBInline</code></td><td align="left" valign="center"> | |
| <p>(bool)Boolean value for the socket OOBINLINE setting. JVM default | |
| used if not set.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.soReuseAddress</code></td><td align="left" valign="center"> | |
| <p>(bool)Boolean value for the sockets reuse address option | |
| (SO_REUSEADDR). JVM default used if not set.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.soLingerOn</code></td><td align="left" valign="center"> | |
| <p>(bool)Boolean value for the sockets so linger option (SO_LINGER). | |
| A value for the standard attribute <strong>connectionLinger</strong> | |
| that is >=0 is equivalent to setting this to <code>true</code>. | |
| A value for the standard attribute <strong>connectionLinger</strong> | |
| that is <0 is equivalent to setting this to <code>false</code>. | |
| Both this attribute and <code>soLingerTime</code> must be set else the | |
| JVM defaults will be used for both.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.soLingerTime</code></td><td align="left" valign="center"> | |
| <p>(int)Value in seconds for the sockets so linger option (SO_LINGER). | |
| This is equivalent to standard attribute | |
| <strong>connectionLinger</strong>. | |
| Both this attribute and <code>soLingerOn</code> must be set else the | |
| JVM defaults will be used for both.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.soTimeout</code></td><td align="left" valign="center"> | |
| <p>This is equivalent to standard attribute | |
| <strong>connectionTimeout</strong>.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.performanceConnectionTime</code></td><td align="left" valign="center"> | |
| <p>(int)The first value for the performance settings. See | |
| <a href="http://docs.oracle.com/javase/6/docs/api/java/net/Socket.html#setPerformancePreferences(int,%20int,%20int)">Socket Performance Options</a> | |
| All three performance attributes must be set else the JVM defaults will | |
| be used for all three.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.performanceLatency</code></td><td align="left" valign="center"> | |
| <p>(int)The second value for the performance settings. See | |
| <a href="http://docs.oracle.com/javase/6/docs/api/java/net/Socket.html#setPerformancePreferences(int,%20int,%20int)">Socket Performance Options</a> | |
| All three performance attributes must be set else the JVM defaults will | |
| be used for all three.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.performanceBandwidth</code></td><td align="left" valign="center"> | |
| <p>(int)The third value for the performance settings. See | |
| <a href="http://docs.oracle.com/javase/6/docs/api/java/net/Socket.html#setPerformancePreferences(int,%20int,%20int)">Socket Performance Options</a> | |
| All three performance attributes must be set else the JVM defaults will | |
| be used for all three.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.unlockTimeout</code></td><td align="left" valign="center"> | |
| <p>(int) The timeout for a socket unlock. When a connector is stopped, it will try to release the acceptor thread by opening a connector to itself. | |
| The default value is <code>250</code> and the value is in milliseconds</p> | |
| </td></tr></table> | |
| </blockquote></td></tr></table> | |
| <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="NIO specific configuration"><!--()--></a><a name="NIO_specific_configuration"><strong>NIO specific configuration</strong></a></font></td></tr><tr><td><blockquote> | |
| <p>The following attributes are specific to the NIO connector.</p> | |
| <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code class="attributeName">socket.directBuffer</code></td><td align="left" valign="center"> | |
| <p>(bool)Boolean value, whether to use direct ByteBuffers or java mapped | |
| ByteBuffers. Default is <code>false</code>.<br> | |
| When you are using direct buffers, make sure you allocate the | |
| appropriate amount of memory for the direct memory space. On Sun's JDK | |
| that would be something like <code>-XX:MaxDirectMemorySize=256m</code>. | |
| </p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.appReadBufSize</code></td><td align="left" valign="center"> | |
| <p>(int)Each connection that is opened up in Tomcat get associated with | |
| a read ByteBuffer. This attribute controls the size of this buffer. By | |
| default this read buffer is sized at <code>8192</code> bytes. For lower | |
| concurrency, you can increase this to buffer more data. For an extreme | |
| amount of keep alive connections, decrease this number or increase your | |
| heap size.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.appWriteBufSize</code></td><td align="left" valign="center"> | |
| <p>(int)Each connection that is opened up in Tomcat get associated with | |
| a write ByteBuffer. This attribute controls the size of this buffer. By | |
| default this write buffer is sized at <code>8192</code> bytes. For low | |
| concurrency you can increase this to buffer more response data. For an | |
| extreme amount of keep alive connections, decrease this number or | |
| increase your heap size.<br> | |
| The default value here is pretty low, you should up it if you are not | |
| dealing with tens of thousands concurrent connections.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.bufferPool</code></td><td align="left" valign="center"> | |
| <p>(int)The NIO connector uses a class called NioChannel that holds | |
| elements linked to a socket. To reduce garbage collection, the NIO | |
| connector caches these channel objects. This value specifies the size of | |
| this cache. The default value is <code>500</code>, and represents that | |
| the cache will hold 500 NioChannel objects. Other values are | |
| <code>-1</code> for unlimited cache and <code>0</code> for no cache.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.bufferPoolSize</code></td><td align="left" valign="center"> | |
| <p>(int)The NioChannel pool can also be size based, not used object | |
| based. The size is calculated as follows:<br> | |
| NioChannel | |
| <code>buffer size = read buffer size + write buffer size</code><br> | |
| SecureNioChannel <code>buffer size = application read buffer size + | |
| application write buffer size + network read buffer size + | |
| network write buffer size</code><br> | |
| The value is in bytes, the default value is <code>1024*1024*100</code> | |
| (100MB).</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.processorCache</code></td><td align="left" valign="center"> | |
| <p>(int)Tomcat will cache SocketProcessor objects to reduce garbage | |
| collection. The integer value specifies how many objects to keep in the | |
| cache at most. The default is <code>500</code>. Other values are | |
| <code>-1</code> for unlimited cache and <code>0</code> for no cache.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.keyCache</code></td><td align="left" valign="center"> | |
| <p>(int)Tomcat will cache KeyAttachment objects to reduce garbage | |
| collection. The integer value specifies how many objects to keep in the | |
| cache at most. The default is <code>500</code>. Other values are | |
| <code>-1</code> for unlimited cache and <code>0</code> for no cache.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">socket.eventCache</code></td><td align="left" valign="center"> | |
| <p>(int)Tomcat will cache PollerEvent objects to reduce garbage | |
| collection. The integer value specifies how many objects to keep in the | |
| cache at most. The default is <code>500</code>. Other values are | |
| <code>-1</code> for unlimited cache and <code>0</code> for no cache.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">selectorPool.maxSelectors</code></td><td align="left" valign="center"> | |
| <p>(int)The max selectors to be used in the pool, to reduce selector | |
| contention. Use this option when the command line | |
| <code>org.apache.tomcat.util.net.NioSelectorShared</code> value is set | |
| to false. Default value is <code>200</code>.</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">selectorPool.maxSpareSelectors</code></td><td align="left" valign="center"> | |
| <p>(int)The max spare selectors to be used in the pool, to reduce | |
| selector contention. When a selector is returned to the pool, the system | |
| can decide to keep it or let it be GC'd. Use this option when the | |
| command line <code>org.apache.tomcat.util.net.NioSelectorShared</code> | |
| value is set to false. Default value is <code>-1</code> (unlimited).</p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">command-line-options</code></td><td align="left" valign="center"> | |
| <p>The following command line options are available for the NIO | |
| connector:<br> | |
| <code>-Dorg.apache.tomcat.util.net.NioSelectorShared=true|false</code> | |
| - default is <code>true</code>. Set this value to <code>false</code> if you wish to | |
| use a selector for each thread. When you set it to <code>false</code>, you can | |
| control the size of the pool of selectors by using the | |
| <strong>selectorPool.maxSelectors</strong> attribute.</p> | |
| </td></tr></table> | |
| </blockquote></td></tr></table> | |
| <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="APR/native specific configuration"><!--()--></a><a name="APR/native_specific_configuration"><strong>APR/native specific configuration</strong></a></font></td></tr><tr><td><blockquote> | |
| <p>The APR/native implementation supports the following attributes in | |
| addition to the common Connector and AJP attributes listed above.</p> | |
| <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code class="attributeName">pollTime</code></td><td align="left" valign="center"> | |
| <p>Duration of a poll call in microseconds. Lowering this value will | |
| slightly decrease latency of connections being kept alive in some cases | |
| , but will use more CPU as more poll calls are being made. The default | |
| value is 2000 (2ms). | |
| </p> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">pollerSize</code></td><td align="left" valign="center"> | |
| <p>Amount of sockets that the poller responsible for polling kept alive | |
| connections can hold at a given time. Extra connections will be closed | |
| right away. The default value is 8192, corresponding to 8192 keep-alive | |
| connections.</p> | |
| </td></tr></table> | |
| </blockquote></td></tr></table> | |
| </blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Nested Components"><!--()--></a><a name="Nested_Components"><strong>Nested Components</strong></a></font></td></tr><tr><td><blockquote> | |
| <p>None at this time.</p> | |
| </blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Special Features"><!--()--></a><a name="Special_Features"><strong>Special Features</strong></a></font></td></tr><tr><td><blockquote> | |
| <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Proxy Support"><!--()--></a><a name="Proxy_Support"><strong>Proxy Support</strong></a></font></td></tr><tr><td><blockquote> | |
| <p>The <code>proxyName</code> and <code>proxyPort</code> attributes can | |
| be used when Tomcat is run behind a proxy server. These attributes | |
| modify the values returned to web applications that call the | |
| <code>request.getServerName()</code> and <code>request.getServerPort()</code> | |
| 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.</p> | |
| <p>For more information, see the | |
| <a href="../proxy-howto.html">Proxy Support HOW-TO</a>.</p> | |
| </blockquote></td></tr></table> | |
| <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Connector Comparison"><!--()--></a><a name="Connector_Comparison"><strong>Connector Comparison</strong></a></font></td></tr><tr><td><blockquote> | |
| <p>Below is a small chart that shows how the connectors differ.</p> | |
| <div class="codeBox"><pre><code> | |
| Java Blocking Connector Java Nio Blocking Connector APR/native Connector | |
| BIO NIO APR | |
| Classname AjpProtocol AjpNioProtocol AjpAprProtocol | |
| Tomcat Version 3.x onwards 7.x onwards 5.5.x onwards | |
| Support Polling NO YES YES | |
| Polling Size N/A maxConnections maxConnections | |
| Read Request Headers Blocking Blocking Blocking | |
| Read Request Body Blocking Blocking Blocking | |
| Write Response Blocking Blocking Blocking | |
| Wait for next Request Blocking Non Blocking Non Blocking | |
| Max Connections maxConnections maxConnections maxConnections | |
| </code></pre></div> | |
| </blockquote></td></tr></table> | |
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