e-docs > WebLogic Server > Using Web Server Plug-Ins With WebLogic Server > Installing and Configuring the Microsoft Internet Information Server (IIS) Plug-In |
Using Web Server Plug-Ins With WebLogic Server |
Installing and Configuring the Microsoft Internet Information Server (IIS) Plug-In
The following sections describe how to install and configure the Microsoft Internet Information Server Plug-In.
Overview of the Microsoft Internet Information Server Plug-In
The Microsoft Internet Information Server Plug-In allows requests to be proxied from a Microsoft Internet Information Server (IIS) to WebLogic Server. The plug-in enhances an IIS installation by allowing WebLogic Server to handle those requests that require the dynamic functionality of WebLogic Server.
You use the Microsoft Internet Information Server Plug-In in an environment where the Internet Information Server (IIS) serves static pages such as HTML pages, while dynamic pages such as HTTP Servlets or JavaServer Pages are served by WebLogic Server. WebLogic Server may be operating in a different process, possibly on a different host. To the end user—the browser—the HTTP requests delegated to WebLogic Server still appear to be coming from IIS. The HTTP-tunneling facility of the WebLogic client-server protocol also operates through the plug-in, providing access to all WebLogic Server services.
Connection Pooling and Keep-Alive
The Microsoft Internet Information Server Plug-In improves performance by using a re-usable pool of connections from the plug-in to WebLogic Server. The plug-in implements HTTP 1.1 keep-alive connections between the plug-in and WebLogic Server by re-using the same connection for subsequent requests from the same client. If the connection is inactive for more than 30 seconds, (or a user-defined amount of time) the connection is closed. The connection with the client can be reused to connect to the same client at a later time if it has not timed out. You can disable this feature if desired. For more information, see KeepAliveEnabled
The plug-in proxies requests to WebLogic Server based on a configuration that you specify. You can proxy requests either based on the URL of the request or a portion of the URL. This is called proxying by path. You can also proxy a request based on the MIME type of the requested file, called proxying by file extension. You can also use a combination of both methods. If a request matches both criteria, the request is proxied by path. You can also specify additional parameters for each of these types of requests that define additional behavior of the plug-in. For more information, see Installing and Configuring the Microsoft Internet Information Server Plug-In.
The Microsoft Internet Information Server Plug-In is supported on Windows. Plug-ins are not supported on all operating systems for all releases. For information on platform support for specific versions of Microsoft Internet Information Server Plug-In, see Platform Support for WebLogic Server Plug-ins and Web Servers in Supported Configurations for WebLogic Server 7.0.
Installing and Configuring the Microsoft Internet Information Server Plug-In
To install the Microsoft Internet Information Server Plug-In:
Note: In the URL, any path information you add after the server and port is passed directly to WebLogic Server. For example, if you request a file from IIS with the URL:
http://myiis.com/jspfiles/myfile.jsp
Note: To avoid out-of-process errors, do not deselect the "Cache ISAPI Applications" check box.
The iisproxy.ini file contains name=value pairs that define configuration parameters for the plug-in. The parameters are listed in General Parameters for Web Server Plug-Ins.
Note: Changes in the parameters will not go into effect until you restart the "IIS Admin Service" (under services, in the control panel).
BEA recommends that you locate the iisproxy.ini file in the same directory that contains the iisproxy.dll file. You can also use other locations. If you place the file elsewhere, note that WebLogic Server searches for iisproxy.ini in the following directories, in the following order:
You can also proxy multiple websites defined in IIS by path. For more information, see Proxying Requests from Multiple Virtual Websites to WebLogic Server.
To configure proxying by path:
WlForwardPath=/weblogic
PathTrim=/weblogic
trims a request from IIS to Weblogic Server. Therefore, /weblogic/session is changed to /session.
WebLogicHost=localhost
WebLogicPort=7001
WebLogicCluster=myweblogic.com:7001,yourweblogic.com:7001
Where myweblogic.com and yourweblogic.com are instances of Weblogic Server running in a cluster.
WlForwardPath=*/HTTPClnt*
Proxying Requests from Multiple Virtual Websites to WebLogic Server
To proxy requests from multiple Websites (defined as virtual directories in IIS) to WebLogic Server:
vhostN=websiteName:port
websiteName:port=dll_directory/iisproxy.ini
vhost1=strawberry.com:7001
strawberry.com:7001=c:\strawberry\iisproxy.ini
vhost2=blueberry.com:7001
blueberry.com:7001=c:\blueberry\iisproxy.ini
...
Here is a sample iisproxy.ini file for use with a single, non-clustered WebLogic Server. Comment lines are denoted with the "#" character.
# This file contains initialization name/value pairs
# for the IIS/WebLogic plug-in.
WebLogicHost=localhost
WebLogicPort=7001
ConnectTimeoutSecs=20
ConnectRetrySecs=2
Here is a sample iisproxy.ini file with clustered WebLogic Servers. Comment lines are denoted with the "#" character.
# This file contains initialization name/value pairs
# for the IIS/WebLogic plug-in.
WebLogicCluster=myweblogic.com:7001,yourweblogic.com:7001
ConnectTimeoutSecs=20
ConnectRetrySecs=2
Note: If you are using SSL between the plug-in and WebLogic Server, the port number should be defined as the SSL listen port.
ACLs will not work through the Microsoft Internet Information Server Plug-In if the Authorization header is not passed by IIS. Use the following information to ensure that the Authorization header is passed by IIS.
When using Basic Authentication, the user is logged on with local log-on rights. To enable the use of Basic Authentication, grant each user account the Log On Locally user right on the IIS server. Two problems may result from Basic Authentication's use of local logon:
To enable Basic Authentication, in the Directory Security tab of the console, ensure that the Allow Anonymous option is "on" and all other options are "off".
Using SSL with the Microsoft Internet Information Server Plug-In
You can use the Secure Sockets Layer (SSL) protocol to protect the connection between WebLogic Server and the Microsoft Internet Information Server Plug-In. The SSL protocol provides confidentiality and integrity to the data passed between the Microsoft Internet Information Server Plug-In and WebLogic Server.
The Microsoft Internet Information Server Plug-In does not use the transport protocol (http or https) to determine whether the SSL protocol will be used to protect the connection between the proxy plug-in and the Microsoft Internet Information Server. In order to use the SSL protocol with the Microsoft Internet Information Server Plug-In, configure the WebLogic Server instance receiving the proxied requests to use the SSL protocol. The port on the WebLogic Server that is configured for secure SSL communication is used by the Microsoft Internet Information Server Plug-In to communicate with the Microsoft Internet Information Server.
To use the SSL protocol between Microsoft Internet Information Server Plug-In and WebLogic Server:
WebLogicHost=myweblogic.com
WebLogicPort=7002
SecureProxy=ON
Specifying Trust for the WL-Proxy-Client-Cert Header
The plug-in can encode users' identity certifications in the WL-Proxy-Client-Cert header and pass the header to WebLogic Server instances (see Proxying Requests to Another Web Server). A WebLogic Server instance uses the certificate information from that header, trusting that it comes from a secure source (the Plug-In), to authenticate the user. In previous releases of WebLogic Server, the default behavior was to always trust the WL-Proxy-Client-Cert header. Beginning with WebLogic Server 6.1 SP2, you need to explicitly define trust of the WL-Proxy-Client-Cert header. A new parameter, clientCertProxy, allows WebLogic Server to determine whether to trust the certificate header. For an additional level of security, use a connection filter to limit all connections into WebLogic Server (therefore allowing WebLogic Server to only accept connections from the machine on which the plug-in is running).
The clientCertProxy parameter has been added to the HTTPClusterServlet and Web applications.
For the HTTPClusterServlet, add the parameter to the web.xml file as follows:
<context-param>
<param-name>clientCertProxy</param-name>
<param-value>true</param-value>
</context-param>
For Web applications, add the parameter to the web.xml file as follows:
ServletRequestImpl context-param
<context-param>
<param-name>weblogic.httpd.clientCertProxy</param-name>
<param-value>true</param-value>
</context-param>
You can also use this parameter in a cluster as follows:
<Cluster ClusterAddress="127.0.0.1" Name="MyCluster"
ClientCertProxyHeader="true"/>
Proxying Servlets from IIS to WebLogic Server
You can proxy servlets by path if the iisforward.dll is registered as a filter. You would then invoke your servlet with a URL similar to the following:
http://IISserver/weblogic/myServlet
To proxy servlets if iisforward.dll is not registered as a filter, you must configure servlet proxying by file type.To proxy servlets by file type:
http://www.myserver.com/virtualName/anyfile.ext
where virtualName is the URL pattern defined in the <servlet-mapping> element of the Web Application deployment descriptor (web.xml) for this servlet and ext is a file type (extension) registered with IIS for proxying to WebLogic Server. The anyfile part of the URL is ignored in this context.
After you install and configure the Microsoft Internet Information Server Plug-In, follow these steps for deployment and testing:
http://myii.server.com/filename.jsp
If filename.jsp is displayed in your browser, the plug-in is functioning.
Connection Errors and Clustering Failover
When the Microsoft Internet Information Server Plug-In attempts to connect to WebLogic Server, the plug-in uses several configuration parameters to determine how long to wait for connections to the WebLogic Server host, and, after a connection is established, how long the plug-in waits for a response. If the plug-in cannot connect or does not receive a response, the plug-in attempts to connect and sends the request to other WebLogic Servers in the cluster. If the connection fails or there is no response from any WebLogic Server instance in the cluster, an error message is sent.
Figure 3-1 demonstrates how the plug-in handles failover.
Possible Causes of Connection Failures
Failure of the WebLogic Server host to respond to a connection request could indicate problems with the host machine, networking problems, or other server failures.
Failure of any WebLogic Server instance in the cluster to respond, could indicate that WebLogic Server is not running or is unavailable, a hung server, a database problem, or other application failure.
Failover with a Single, Non-Clustered WebLogic Server
If you are running only a single WebLogic Server, the plug-in only attempts to connect to the server defined with the WebLogicHost parameter. If the attempt fails, an HTTP 503 error message is returned. The plug-in continues trying to connect to WebLogic Server until ConnectTimeoutSecs is exceeded.
When you specify a list of WebLogic Servers in the WebLogicCluster parameter, the plug-in uses that list as a starting point for load balancing among the members of the cluster. After the first request is routed to one of these servers, a dynamic server list is returned containing an updated list of servers in the cluster. The updated list adds any new servers in the cluster and deletes any that are no longer part of the cluster or that have failed to respond to requests. This list is updated automatically with the HTTP response when a change in the cluster occurs.
Failover, Cookies, and HTTP Sessions
When a request contains a session information stored in a cookie, in the POST data, or by URL encoding, the session ID contains a reference to the specific server in which the session was originally established (called the primary server) and a reference to an additional server where the original session is replicated (called the secondary server). A request containing a cookie attempts to connect to the primary server. If that attempt fails, the request is routed to the secondary server. If both the primary and secondary servers fail, the session is lost and the plug-in attempts to make a fresh connection to another server in the dynamic cluster list. For more information see Figure 3-1 Connection Failover.
Note: If the POST data is larger than 64K, the plug-in will not parse the POST data to obtain the session ID. Therefore, if you store the session ID in the POST data, the plug-in cannot route the request to the correct primary or secondary server, resulting in possible loss of session data.
Figure 3-1 Connection Failover
Notes: The HTTP error code thrown by the plug-in depends on the situation. Plug-in will return the HTTP error code 500 in the following conditions:
On the other hand, the HTTP error code 503 is returned when: