1. Developing Web Applications, Servlets, and JSPs for Oracle WebLogic Server
  2. HTTP Proxy Servlet Parameters

E HTTP Proxy Servlet Parameters

Read descriptions of the HttpProxyServlet parameters.

This appendix includes the following topics:

Debug

Default: OFF

Sets the type of logging performed for debugging operations. The debugging information is written to c:\TEMP\wlproxy.log on Windows NT/2000 systems.

Override this location and filename by setting the WLLogFile parameter to a different directory and file. (See the WLTempDir parameter for an additional way to change this location.)

Ensure that the directory of the log file has write permission. Set any of the following logging options (HFC,HTW,HFW, and HTC options may be set in combination by entering them separated by commas, for example "HFC,HTW"):

  • ON: The plug-in logs informational and error messages.

  • OFF: No debugging information is logged.

  • HFC: The plug-in logs headers from the client, informational, and error messages.

  • HTW: The plug-in logs headers sent to WebLogic Server, and informational and error messages.

  • HFW: The plug-in logs headers sent from WebLogic Server, and informational and error messages.

  • HTC: The plug-in logs headers sent to the client, informational messages, and error messages.

  • ERR: Prints only the Error messages in the plug-in.

  • ALL: The plug-in logs headers sent to and from the client, headers sent to and from WebLogic Server, information messages, and error messages.

Note:

For HttpProxyServlet, there are only two options: TRUE(ON) and FALSE(OFF).

For information on setting logging without using the deprecated parameter, see Deprecated Directives for Apache HTTP Server.

DebugConfigInfo

Default: OFF

Enables the special query parameter "__WebLogicBridgeConfig". Use it to get details about configuration parameters from the plug-in.

For example, if you enable "__WebLogicBridgeConfig" by setting DebugConfigInfo and then send a request that includes the query string ?__WebLogicBridgeConfig, then the plug-in gathers the configuration information and run-time statistics and returns the information to the browser. The plug-in does not connect to WebLogic Server in this case.

This parameter is strictly for debugging and the format of the output message can change with releases. For security purposes, keep this parameter turned OFF in production systems.

DefaultFileName

Default: none

If the URI is "/" then the plug-in performs the following steps:

  1. Trims the path specified with the PathTrim parameter.

  2. Appends the value of DefaultFileName.

  3. Prepends the value specified with PathPrepend.

This procedure prevents redirects from WebLogic Server.

Set the DefaultFileName to the default welcome page of the Web Application in WebLogic Server to which requests are being proxied. For example, If the DefaultFileName is set to welcome.html, an HTTP request like "http://somehost/weblogic" becomes "http://somehost/weblogic/welcome.html". For this parameter to function, the same file must be specified as a welcome file in all the Web Applications to which requests are directed. See Configuring Welcome Files in Developing Web Applications, Servlets, and JSPs for Oracle WebLogic Server.

Note for Apache users: If you are using Stronghold or Raven versions, define this parameter inside of a Location block, and not in an IfModule block.

FileCaching

Default: ON

When set to ON, and the size of the POST data in a request is greater than 2048 bytes, the POST data is first read into a temporary file on disk and then forwarded to the WebLogic Server in chunks of 8192 bytes. This preserves the POST data during failover, allowing all necessary data to be repeated to the secondary if the primary goes down.

When FileCaching is ON, any client that tracks the progress of the POST will see that the transfer has completed even though the data is still being transferred between the WebServer and WebLogic. So, if you want the progress bar displayed by a browser during the upload to reflect when the data is actually available on the WebLogic Server, you might not want to have FileCaching ON.

When set to OFF and the size of the POST data in a request is greater than 2048 bytes, the reading of the POST data is postponed until a WebLogic Server cluster member is identified to serve the request. Then the plug-in reads and immediately sends the POST data to the WebLogic Server in chunks of 8192 bytes.

Turning FileCaching OFF limits failover. If the WebLogic Server primary server goes down while processing the request, the POST data already sent to the primary cannot be repeated to the secondary.

Finally, regardless of how FileCaching is set, if the size of the POST data is 2048 bytes or less the plug-in will read the data into memory and use it if needed during failover to repeat to the secondary.

KeepAliveEnabled

Default: true

Enables pooling of connections between the plug-in and WebLogic Server.

  • Valid values for the Microsoft IIS plug-ins and HttpProxyServlet are true and false.

  • Valid values for the Apache HTTP Server are ON and OFF.

    While using Apache prefork mpm, Apache web server might fail. Set KeepAliveEnabled to OFF when using prefork mpm or use worker mpm in Apache.

Note:

If both KeepAliveEnabled and HTTP/2 are configured for a backend connection, the following message is generated:

KeepAliveEnabled option will be ignored since HTTP/2 connection is enabled

KeepAliveSecs

Default: 20

The length of time after which an inactive connection between the plug-in and WebLogic Server is closed. You must set KeepAliveEnabled to true (ON when using the Apache HTTP Server) for this parameter to be effective.

The value of this parameter must be less than or equal to the value of the Duration field set in the Administration Console on the Server/HTTP tab, or the value set on the server Mbean with the KeepAliveSecs attribute.

MaxPostSize

Default: 0

Maximum allowable size of POST data, in bytes. If the content-length exceeds MaxPostSize, the plug-in returns an error message. If set to 0, the size of POST data is not checked. This is useful for preventing denial-of-service attacks that attempt to overload the server with POST data.

PathPrepend

Default: null

As per the RFC specification, generic syntax for URL is:

[PROTOCOL]://[HOSTNAME]:{PORT}/{PATH}/{FILENAME};{PATH_PARAMS}/{QUERY_STRING}...

PathPrepend specifies the path that the plug-in prepends to the {PATH} portion of the original URL, after PathTrim is trimmed and before the request is forwarded to WebLogic Server.

If you must append a File Name, use DefaultFileName parameter instead of PathPrepend.

PathTrim

Default: null

As per the RFC specification, generic syntax for URL is:

[PROTOCOL]://[HOSTNAME]:{PORT}/{PATH}/{FILENAME};{PATH_PARAMS}/{QUERY_STRING}...

PathTrim specifies the string trimmed by the plug-in from the {PATH}/{FILENAME} portion of the original URL, before the request is forwarded to WebLogic Server. For example, if this URL:

http://myWeb.server.com/weblogic/foo

is passed to the plug-in for parsing and if PathTrim has been set to strip off /weblogic before handing the URL to WebLogic Server, the URL forwarded to WebLogic Server is:

http://myWeb.server.com:7001/foo

If you are newly converting an existing third-party server to proxy requests to WebLogic Server using the plug-in, you will need to change application paths to /foo to include weblogic/foo. You can use PathTrim and PathPrepend in combination to change this path.

SecureProxy

Default: OFF

Set this parameter to ON to enable the use of the SSL protocol for all communication between the plug-in and WebLogic Server. Remember to configure a port on the corresponding WebLogic Server for the SSL protocol before defining this parameter.

This parameter may be set at two levels: in the configuration for the main server and—if you have defined any virtual hosts—in the configuration for the virtual host. The configuration for the virtual host inherits the SSL configuration from the configuration of the main server if the setting is not overridden in the configuration for the virtual host.

WebLogicHost

Required when proxying to a single WebLogic Server.

Default: none

WebLogic Server host (or virtual host name as defined in WebLogic Server) to which HTTP requests should be forwarded. If you are using a WebLogic cluster, use the WebLogicCluster parameter instead of WebLogicHost.

WebLogicPort

Required when proxying to a single WebLogic Server.

Default: none

Port at which the WebLogic Server host is listening for connection requests from the plug-in (or from other servers). (If you are using SSL between the plug-in and WebLogic Server, set this parameter to the SSL listen port and set the SecureProxy parameter to ON).

If you are using a WebLogic Cluster, use the WebLogicCluster parameter instead of WebLogicPort.

WLCookieName

Default: JSESSIONID

If you change the name of the WebLogic Server session cookie in the WebLogic Server Web application, then you must change the WLCookieName parameter in the plug-in to the same value. The name of the WebLogic session cookie is set in the WebLogic-specific deployment descriptor, in the <session-descriptor> element in weblogic.xml.

WLIOTimeoutSecs

New name for HungServerRecoverSecs.

Default: 120

Defines the amount of time the plug-in waits for a response to a request from WebLogic Server. The plug-in waits for WLIOTimeoutSecs for the server to respond and then declares that server dead, and fails over to the next server. You must set the value to a large value. If the value is less than the time the servlets take to process, then you might see unexpected results.

Minimum value: 10

Maximum value: 2147483647

WLLogFile

Default: See the Debug parameter.

Specifies path and file name for the log file that is generated when the Debug parameter is set to ON. You must create this directory before setting this parameter.

For information on setting logging without using the deprecated parameter, see Deprecated Directives for Apache HTTP Server.

WLProxyPassThrough

Default: OFF

If you have a chained proxy setup, where a proxy plug-in or HttpClusterServlet is running behind some other proxy or load balancer, you must explicitly enable the WLProxyPassThrough parameter. This parameter allows the header to be passed through the chain of proxies.

WLProxySSL

Default: OFF

Set this parameter to ON to maintain SSL communication between the plug-in and WebLogic Server when the following conditions exist:

  • An HTTP client request specifies the HTTPS protocol

  • The request is passed through one or more proxy servers (including the Oracle WebLogic Server Proxy Plug-In)

  • The connection between the plug-in and WebLogic Server uses the HTTP protocol

When WLProxySSL is set to ON, the location header returned to the client from WebLogic Server specifies the HTTPS protocol.

WLProxySSLPassThrough

Default: OFF

If a load balancer or other software deployed in front of the web server and plug-in is the SSL termination point, and that product sets the WL-Proxy-SSL request header to true or false based on whether the client connected to it over SSL, set WLProxySSLPassThrough to ON so that the use of SSL is passed on to the Oracle WebLogic Server.

If the SSL termination point is in the web server where the plug-in operates, or the load balancer does not set WL-Proxy-SSL, set WLProxySSLPassThrough to OFF (default).