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Oracle® Coherence User's Guide for Oracle Coherence*Web
Release 3.6.1

Part Number E15829-02
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2 Using Coherence*Web with WebLogic Server

Note:

Except where noted, this chapter pertains to the 11g Release 2 (10.3.3) of WebLogic Server.

Coherence*Web provides session state persistence and management. It is a session management module that uses Coherence for storing and managing session data. This chapter describes how to set up and deploy Coherence*Web so that it can be used by applications running on WebLogic Server.

Coherence*Web is an alternative to WebLogic Server's in-memory HTTP state replication services. Consider using Coherence*Web if you are encountering any of these situations:

2.1 Overview of the Coherence*Web SPI

The Coherence*Web Service Provider Interface (SPI) consists of the coherence-web-spi.war file. To enable Coherence*Web functionality, the SPI also requires coherence.jar.

2.1.1 Coherence*Web SPI Configurations

In Coherence*Web, the following default cache configurations are defined:

  • The Coherence*Web SPI for WebLogic Server is configured with local-storage disabled. The server will serve requests and will not be used to host data. This means a Coherence cache server must be running in its own JVM, separate from the JVM running WebLogic Server.

  • The timeout for requests to the cache server to respond is 30 seconds. If a request to the cache server has not responded in 30 seconds, a com.tangosol.net.RequestTimeoutException exception is thrown.

The session-cache-config.xml file contains the Coherence cache configurations used by the Coherence*Web SPI. This file is located in the coherence-web-spi.war file under the WEB-INF\classes directory. Enter any cache configuration changes in the session-cache-config.xml file and then repackage it in the coherence-web-spi.war file.

Coherence*Web provides several session locking modes to control concurrent access of sessions. Both Coherence*Web and the Coherence*Web SPI employ Optimistic locking by default. This allows concurrent access to a session by multiple threads in a single JVM or multiple JVMs while prohibiting concurrent modification. See "Session Locking Modes" for more information about locking modes.

By itself, the Coherence*Web SPI does not require a load balancer to run in front of the WebLogic Server tier. However, you will require a load balancer if you employ sticky session optimization with any of the non-Optimistic locking modes. The default load balancer enforces HTTP session JVM affinity, however, other load balancing alternatives are available. WebLogic Server ships with several different proxy plug-ins which enforce JVM session stickiness. Documentation for configuring the WebLogic Server proxy plug-in is available here:

http://download.oracle.com/docs/cd/E12840_01/wls/docs103/cluster/load_balancing.html#wp1026940

2.2 Configuring And Deploying Coherence*Web on WebLogic Server—Main Steps

Coherence*Web includes a deployable shared library that contains a native plug-in to WebLogic Server's HTTP Session Management interface. The following steps summarize how to prepare your deployments to use Coherence*Web with applications running on WebLogic Server:

  1. Download Oracle Coherence to your file system. See "Download Oracle Coherence".

  2. Modify the web.xml file in the WAR deployment if your application requires advanced configuration for Coherence*Web. "Configure Coherence*Web" describes the parameters that can be configured for Web applications. See Appendix A, "Coherence*Web Context Parameters" for descriptions of the entire set of Coherence*Web parameters.

  3. (Optional) Configure the WebLogic-generated HTTP session cookie parameters in weblogic.xml or weblogic-application.xml. See "Configure the Session Cookies".

  4. (Optional for testing; strongly suggested for production) Start a Cache Server Tier in a separate JVM from the one running WebLogic Server. See "Start a Cache Server".

  5. Determine the appropriate packaging based on your deployment requirements and follow the packaging instructions. Depending on your version of Weblogic Server, see "Configure Cluster Nodes (WebLogic Server 10.3.3 and Later)" or "Configure Cluster Nodes (WebLogic Server 10.3.2 and Earlier)".

2.2.1 Download Oracle Coherence

All of the files supporting Coherence*Web, including coherence-web-spi.war are included in the Coherence distribution.

By default, Coherence 3.5 is installed with WebLogic Server 10.3.3. If you are using Weblogic Server 10.3.3, you must replace the contents of the coherence directory that was installed with the server with the contents of the Coherence 3.6 distribution. The default location of the Coherence directory is C:\Oracle\Middleware\coherence_3.5.

If you are using WebLogic Server 10.3.2 or earlier, download the Coherence distribution to your file system.

2.2.2 Configure Coherence*Web

The Coherence*Web SPI provides a default configuration that should satisfy most Web applications. Table 2-1 lists only those Coherence*Web context parameters where the default for the SPI version is different from the non-SPI version. For a full descriptions of all Coherence*Web parameters, see Appendix A, "Coherence*Web Context Parameters."

You can also configure the context parameters on the command line as system properties. The system properties have the same name as the context parameters, but the dash (-) is replaced with a period (.). For example, to declare a value for the context parameter coherence-enable-sessioncontext on the command line, enter it like this:

-Dcoherence.enable.sessioncontext=true

If both a system property and the equivalent context parameter are configured, the value from the system property is honored.

Table 2-1 Coherence*Web SPI Context Parameters

Parameter Name Description

coherence-application-name

Coherence*Web uses the value of this parameter to determine the name of the application that uses ApplicationScopeController to scope attributes. The value for this parameter should be provided in the following format:

application name + ! + Web module name

where application name is the name of the application that uses ApplicationScopeController and Web module name is the name of the Web module in which it appears.

For example, if you have an EAR named test.ear and a Web-module named app1 defined in the EAR, then the default value for coherence-application-name would be test!app1.

If this parameter is not configured, then Coherence*Web uses the name of the class loader instead. Also, if the parameter is not configured and ApplicationScopeController is configured, then a warning is logged saying that the application name was not configured. See "Session Attribute Scoping" for more information.

coherence-factory-class

The fully qualified class name of the SessionHelper.Factory to use.

Other possible values include com.tangosol.coherence.servlet.apiXX.DefaultFactory where XX is 22, 23, 24, or 25 for Servlet 2.2, 2.3, 2.4, or 2.5 containers respectively.

Default is weblogic.servlet.internal.session.WebLogicSPIFactory

coherence-reaperdaemon-assume-locality

This setting allows the reaper to assume that the sessions that are stored on this node (for example, by a distributed cache service) are the only sessions that this node must check for expiry. This value must be set to false if the session storage cache is being managed by nodes that are not running a reaper, for example if cache servers are being used to manage the session storage cache.

If cache servers are being used, select the "split" model and run the session overflow storage in a separate distributed cache service that is managed entirely by the cache servers. Leave the session storage cache itself in a distributed cache service that is managed entirely by the application server JVMs so they can take advantage of this "assume locality" feature.

Default is false.

coherence-scopecontroller-class

This value specifies the class name of the optional com.tangosol.coherence.servlet.HttpSessionCollection$AttributeScopeController interface implementation to use.

Valid values include:

Default is com.tangosol.coherence.servlet.AbstractHttpSessionCollection$ApplicationScopeController

coherence-session-weblogic-compatibility-mode

This parameter is available only for the SPI version of Coherence*Web. If its value is set to true, it determines that a single session ID (with the cookie path set to "/") will map to a unique Coherence*Web session instance in each web-app. If it is false, then the standard behavior will apply: a single session ID will map to a single session instance using the Coherence*Web SPI in WebLogic. All other session persistence mechanisms in WebLogic use a single session ID in each web-app to refer to different session instances.

Defaults to true unless the global scope controller is specified. If the controller is specified, then it defaults to false.


2.2.3 Configure the Session Cookies

If you run the Coherence*Web SPI, then WebLogic Server generates and parses the session cookie. Any native Coherence*Web session cookie configuration parameters will be ignored. Session cookies must be configured by using the session cookie parameters in weblogic.xml or weblogic-application.xml.

Table 2-2 describes the WebLogic-generated HTTP session cookie parameters that you can configure in weblogic.xml or weblogic-application.xml.

In this table, Updatable? indicates whether the value of the parameter can be changed while the server is running. n/a indicates that there is no corresponding Coherence cookie parameter.

Table 2-2 HTTP Session Cookie Parameters

This WebLogic-Generated Session Cookie Parameter... Replaces this Coherence*Web Cookie Parameter Description

cookie-comment

n/a

Specifies the comment that identifies the session tracking cookie in the cookie file.

Default is null.

Updatable? Yes

cookie-domain

coherence-session-cookie-domain

Specifies the domain for which the cookie is valid. For example, setting cookie-domain to.mydomain.com returns cookies to any server in the *.mydomain.com domain.

The domain name must have at least two components. Setting a name to *.com or *.net is not valid.

If not set, this attribute defaults to the server that issued the cookie.

For more information, see Cookie.setDomain() in the Servlet specification from Sun Microsystems.

Default is null.

Updatable? Yes

cookie-max-age-secs

coherence-session-max-age

Sets the life span of the session cookie, in seconds, after which it expires on the client. For more information about cookies, see Using Sessions and Session Persistence.

The default value is -1 (unlimited).

Updatable? Yes

cookie-name

coherence-session-cookie-name

Defines the session tracking cookie name. Defaults to JSESSIONID if not set. You may set this to a more specific name for your application.

Default is JSESSIONID.

Updatable? Yes

cookie-path

coherence-session-cookie-path

Defines the session tracking cookie path.

If not set, this attribute defaults to / (slash) where the browser sends cookies to all URLs served by WebLogic Server. You may set the path to a narrower mapping, to limit the request URLs to which the browser sends cookies.

Default is null.

Updatable? Yes

cookie-secure

coherence-session-cookie-secure

Tells the browser to only send the cookie back over an HTTPS connection. This ensures that the cookie ID is secure and should only be used on Web sites that use HTTPS. Session Cookies over HTTP no longer work if this feature is enabled.

You should disable the url-rewriting-enabled element if you intend to use this feature.

WebLogic Server generates the session cookie

Default is false.

Updatable? Yes

cookies-enabled

coherence-session-cookies-enabled

Use of session cookies is enabled by default and is recommended, but you can disable them by setting this property to false. You might turn this option off for testing purposes.

Default is true.

Updatable? Yes

debug-enabled

n/a

Enables the debugging feature for HTTP sessions. Support it by enabling HttpSessionDebug logging and the WebLogic Server trace logger.

Default value is false.

Updatable? Yes

encode-session-id-in-query-params

n/a

The latest servlet specification requires containers to encode the session ID in path parameters. Certain Web servers do not work well with path parameters. In such cases, the encode-session-id-in-query-params element should be set to true.

WebLogic Server generates the HTTP response.

Default value is false.

Updatable? Yes

http-proxy-caching-of-cookies

n/a

When set to false, WebLogic Server adds the following header and response to indicate that the proxy caches are not caching the cookies.:“Cache-control: no-cache=set-cookie

WebLogic Server generates the HTTP response.

Default value is true.

Updatable? Yes

id-length

coherence-session-id-length

Sets the size of the session ID.

The minimum value is 8 bytes and the maximum value is Integer.MAX_VALUE.

If you are writing a WAP application, you must use URL rewriting because the WAP protocol does not support cookies. Also, some WAP devices have a 128-character limit on URL length (including attributes), which limits the amount of data that can be transmitted using URL re-writing. To allow more space for attributes, use this attribute to limit the size of the session ID that is randomly generated by WebLogic Server.

You can also limit the length to a fixed 52 characters, and disallow special characters, by setting the WAPEnabled attribute. For more information, see "URL Rewriting and Wireless Access Protocol" in Developing Web Applications for WebLogic Server.

Default is 52.

Updatable? No

invalidation-interval-secs

coherence-reaperdaemon-cycle-seconds

Sets the time, in seconds, that Coherence*Web waits between doing house-cleaning checks for timed-out and invalid sessions, and deleting the old sessions and freeing up memory. Use this element to tune WebLogic Server for best performance on high traffic sites.

Default is 60.

Updatable? No

timeout-secs

coherence-session-expire-seconds

Sets the time, in seconds, that Coherence*Web waits before timing out a session.

On busy sites, you can tune your application by adjusting the timeout of sessions. While you want to give a browser client every opportunity to finish a session, you do not want to tie up the server needlessly if the user has left the site or otherwise abandoned the session.

This element can be overridden by the session-timeout element (defined in minutes) in web.xml.

Default is 3600 seconds.

Updatable? No

tracking-enabled

n/a

Enables session tracking between HTTP requests.

WebLogic Server generates the HTTP response.

Default is true.

Updatable? No

url-rewriting-enabled

coherence-session-urlencode-enabled

Enables URL rewriting, which encodes the session ID into the URL and provides session tracking if cookies are disabled in the browser and the encodeURL or encodeRedirectedURL methods are used when writing out URLs. For more information, see:

http://www.jguru.com/faq/view.jsp?EID=1045

WebLogic Server generates the HTTP response.

Default is true.

Updatable? Yes


2.2.4 Start a Cache Server

A Coherence data node (also known as a cache server) is responsible for storing and managing all cached data. It can be either a dedicated JVM or run within a WebLogic Server instance. The senior node (which is the first node) in a Coherence data cluster can take several seconds to start up; the start-up time required by subsequent nodes is minimal.

Whether you start the cache servers first or the WebLogic Server instances first, depends on the server topology you are employing.

  • If you are using an In-Process topology (all storage-enabled WebLogic Server instances), then it does not matter if you start the cache servers first or WebLogic Server instances first.

  • If you are using an Out-of-Process topology (storage-disabled WebLogic server instances and stand alone Coherence cache servers), then start the cache servers first, followed by the WebLogic Server instances. This will ensure that there is minimal (measured in milliseconds) startup time for applications using Coherence. Any additional Web applications that use Coherence are guaranteed not to be the senior data member, so they will have minimal impact on WebLogic Server startup.

To Start a Stand-Alone Coherence Data Node

  1. Create a script for starting a Coherence data node. The following is an example of a script that starts a storage-enabled cache server. This example assumes that you are using a Sun JVM. See "JVM Tuning" in the Developer's Guide for Oracle Coherence for more information.

    java -server -Xms512m -Xmx512m 
    -cp <Coherence installation dir>/lib/coherence.jar:<Coherence installation dir>/lib/coherence-web-spi.war -Dtangosol.coherence.management.remote=true 
    -Dtangosol.coherence.cacheconfig=WEB-INF/classes/cache_configuration_file 
    -Dtangosol.coherence.session.localstorage=true com.tangosol.net.DefaultCacheServer
    

    In this example, cache_configuration_file refers to the cache configuration in the coherence-cache-config.xml file. (Note: if you are only running Coherence*Web, then cache_configuration_file is session-cache-config.xml.) The cache configuration defined for the cache server must be the same as the configuration defined for the application servers which run on the same Coherence cluster.

    If you run Coherence*Web for session management, then the information about the cache configuration should be merged with the session configuration contained in the session-cache-config.xml file. Similarly, the cache and session configuration must be consistent across WebLogic and Cache servers.

  2. Start one or more Coherence data nodes using the script described in the previous step.

To Start a Storage-Enabled or -Disabled WebLogic Server Instance

By default, a Coherence*Web-enabled WebLogic Server instance starts in storage-disabled mode.

To start the WebLogic Server instance in storage-enabled mode, include the command line property -Dtangosol.coherence.session.localstorage=true in the server startup command.

For more information on working with WebLogic Server through the command line, see "weblogic.Server Command-Line Reference" in the Oracle Fusion Middleware Command Reference for Oracle WebLogic Server.

2.2.5 Configure Cluster Nodes (WebLogic Server 10.3.3 and Later)

Coherence*Web can have application server-scope, EAR-scope, or WAR-scope. Like Coherence clusters, scoping of Coherence*Web depends on the placement of the coherence.jar file in the classloader's hierarchy. You can find detailed information about each of the scopes in "Cluster Node Isolation".

WebLogic Server 10.3.3 provides several features, collectively known as ActiveCache, that allow your applications to more easily interact with the Coherence cache. For a complete discussion of these features see the Using ActiveCache guide. To employ ActiveCache functionality in your applications, you must also deploy the active-cache.jar file, which you can find in the WL_HOME/common/deployable-libraries directory.

The following sections describe how you can configure the different cluster node configurations to run Coherence*Web:

Note:

Consider the use of the application server-scoped cluster configuration very carefully. Do not use it in environments where application interaction is unknown or unpredictable.

An example of such an environment might be a deployment where multiple application teams are deploying applications written independently, without carefully coordinating and enforcing their conventions and naming standards. With this configuration, all applications are part of the same cluster—the likelihood of collisions between namespaces for caches, services, and other configuration settings is quite high and could lead to unexpected results.

For these reasons, Oracle Coherence strongly recommends that you use EAR-scoped and WAR-scoped cluster node configurations. If you are in doubt regarding which deployment topology to choose, or if this warning applies to your deployment, then do not choose the application server-scoped cluster node configuration.

2.2.5.1 Configuring Application Server-Scoped Cluster Nodes

To add Coherence*Web for session management to a Coherence cluster, follow these steps:

  1. Edit your WebLogic Server system classpath to include the coherence.jar and WL_HOME/common/deployable-libraries/active-cache.jar files in the system classpath. The active-cache.jar file should be referenced only from the deployable-libraries folder in the system classpath and should not be copied to any other location.

  2. Use the WebLogic Server Administration Console or the command line to deploy coherence-web-spi.war file as a shared library.

  3. Enable Coherence*Web in your Web application.

    Add the library reference code illustrated in Example 2-1 to the weblogic.xml file in each WAR file deployed in the WebLogic Server that intends to use Coherence*Web.

    Example 2-1 Library Reference for a WAR File

    <weblogic-web-app>
      ...
        <library-ref>
          <library-name>coherence-web-spi</library-name>
        </library-ref>
      ...
    </weblogic-web-app>
    
  4. (Optional) If you must configure Coherence cluster properties, create a CoherenceClusterSystemResourceMBean MBean and reference it in the ServerMBean MBean.

    You can use WebLogic Scripting Tool (WLST) to reference the MBean. See createServerScopedCoherenceSystemResource in the Using ActiveCache book.

2.2.5.2 Configuring EAR-Scoped Cluster Nodes

To use Coherence*Web for session management in EAR-scoped cluster nodes, follow these steps:

  1. Use the WebLogic Server Administration Console or the command line to deploy the coherence.jar, active-cache.jar, and coherence-web-spi.war files as shared libraries to all of the target servers where the application will be deployed.

    See "Install a Java EE Library" in the Oracle Fusion Middleware Oracle WebLogic Server Administration Console Help.

  2. Reference the coherence.jar, active-cache.jar, and coherence-web-spi.war files in the weblogic-application.xml file. Store the file in the EAR's META-INF/ directory.

    Example 2-2 illustrates a sample weblogic-application.xml file.

    Example 2-2 Coherence, Coherence Web SPI, and ActiveCache Referenced in weblogic-application.xml

    <weblogic-application ... >
    ...
          <library-ref>
               <library-name>coherence</library-name>
          </library-ref>
          <library-ref>
               <library-name>coherence-web-spi</library-name>
         </library-ref>
         <library-ref>
               <library-name>active-cache</library-name>
         </library-ref>
    ...
    </weblogic-application>
    
  3. (Optional) If you must configure Coherence cluster properties, create a CoherenceClusterSystemResourceMBean MBean and reference it as a coherence-cluster-ref element in weblogic.xml file. This element allows the applications to enroll in the Coherence cluster as specified by the CoherenceClusterSystemResourceMBean attributes. For more information, see the Using ActiveCache book.

    Example 2-3 illustrates a sample configuration. The myCoherenceCluster MBean in the example is of type CoherenceClusterSystemResourceMBean.

    Example 2-3 Identifying a Coherence Cluster for EAR-Scoped Cluster Nodes

    <weblogic-web-app>
    ...
      <coherence-cluster-ref>
        <coherence-cluster-name>
         myCoherenceCluster
        </coherence-cluster-name>
      </coherence-cluster-ref> 
    ...
    </weblogic-web-app>  
    

2.2.5.3 Configuring WAR-Scoped Cluster Nodes

To use Coherence*Web for session management in WAR-scoped cluster nodes, follow these steps:

  1. Use the WebLogic Server Administration Console or the command line to deploy the active-cache.jar and coherence-web-spi.war files as shared libraries to all of the target servers where the application will be deployed. See "Install a Java EE Library" in the Oracle Fusion Middleware Oracle WebLogic Server Administration Console Help.

  2. Copy the coherence.jar file to the WAR file's WEB-INF/lib directory.

  3. If you deploy the coherence-web-spi.war file as a shared library, you must also create a shared library reference by adding the stanza illustrated in Example 2-4 to the weblogic.xml file in the WAR file's WEB-INF directory.

    Example 2-4 Library Reference for a Web Application

    <weblogic-web-app ... >
         ...
          <library-ref>
               <library-name>coherence-web-spi</library-name>
         </library-ref>
         ...
    <weblogic-web-app>
    
  4. Create a manifest.mf file to reference the active-cache.jar file. Copy the manifest.mf file to each WAR file's META-INF directory. Example 2-5 illustrates a sample manifest.mf file.

    Example 2-5 Sample manifest.mf File to Reference active-cache.jar

    Extension-List: active-cache
    active-cache-Extension-Name: active-cache
    active-cache-Specification-Version: 1.0
    active-cache-Implementation-Version: 1.0
    
  5. (Optional) If you must configure Coherence cluster properties, create a CoherenceClusterSystemResourceMBean MBean and reference it as a coherence-cluster-ref element in the weblogic.xml or weblogic-ejb-jar.xml file. For more information, see the Using ActiveCache book.

    Example 2-6 illustrates a sample configuration for WAR-scoped cluster nodes in the weblogic.xml file. The myCoherenceCluster MBean is of type CoherenceClusterSystemResourceMBean.

    Example 2-6 Identifying a Coherence Cluster for EAR-Scoped Cluster Nodes

    <weblogic-web-app>
    ...
      <coherence-cluster-ref>
        <coherence-cluster-name>
         myCoherenceCluster
        </coherence-cluster-name>
      </coherence-cluster-ref> 
    ...
    </weblogic-web-app>
    

2.2.6 Configure Cluster Nodes (WebLogic Server 10.3.2 and Earlier)

WebLogic Server 10.3.2 and earlier does not support ActiveCache.

Coherence cluster nodes are classloader scoped. Therefore, you must configure the number of unique Coherence cluster nodes in a Coherence*Web deployment before packaging the application(s). The packaging and configuration options are described in the following sections:

You can find detailed information about each of the options under "Cluster Node Isolation".

Note:

Consider the use of the application server-scoped cluster configuration very carefully. Do not use it in environments where application interaction is unknown or unpredictable.

An example of such an environment might be a deployment where multiple application teams are deploying applications written independently, without carefully coordinating and enforcing their conventions and naming standards. With this configuration, all applications are part of the same cluster—the likelihood of collisions between namespaces for caches, services, and other configuration settings is quite high and could lead to unexpected results.

For these reasons, Oracle Coherence strongly recommends that you use EAR-scoped and WAR-scoped cluster node configurations. If you are in doubt regarding which deployment topology to choose, or if this warning applies to your deployment, then do not choose the application server-scoped cluster node configuration.

2.2.6.1 Configuring Application Server-Scoped Cluster Nodes

To add Coherence*Web for session management to a Coherence cluster, follow these steps:

  1. Deploy the coherence-web-spi.war file as a shared library on each WebLogic Server.

  2. Edit your WebLogic Server system classpath to include the coherence.jar file or copy the JAR file to your $DOMAIN_HOME/lib directory.

  3. Enable Coherence*Web in your Web application.

    Add the library reference stanza illustrated in Example 2-7 to the weblogic.xml file in each WAR file deployed in the WebLogic Server that intends to use Coherence*Web.

    Example 2-7 Library Reference for a WAR File

    <weblogic-web-app>
         ...
          <library-ref>
               <library-name>coherence-web-spi</library-name>
         </library-ref>
         ...
    </weblogic-web-app> 
    

2.2.6.2 Configuring EAR-Scoped Cluster Nodes

To use Coherence*Web for session management in EAR-scoped cluster nodes, follow these steps:

  1. Use the WebLogic Server Administration Console to deploy the coherence.jar and coherence-web-spi.war files as shared libraries to all of the target servers where the application will be deployed. See "Install a Java EE Library" in Oracle Fusion Middleware Oracle WebLogic Server Administration Console Help for more information.

  2. Reference the coherence.jar and coherence-web-spi.war files in the weblogic-application.xml file. Store the file in the EAR's META-INF directory.

    Example 2-8 illustrates a weblogic-application.xml file.

    Example 2-8 Coherence and Coherence Web SPI Referenced in weblogic-application.xml

    <weblogic-application ...>
    ...
          <library-ref>
               <library-name>coherence</library-name>
          </library-ref>
          <library-ref>
               <library-name>coherence-web-spi</library-name>
         </library-ref>
    ...
    </weblogic-application>
    

2.2.6.3 Configuring WAR-Scoped Cluster Nodes

To use Coherence*Web for session management in WAR-scoped cluster nodes, follow these steps:

  1. Use the WebLogic Server Administration Console or the command line to deploy the coherence-web-spi.war file as a shared library to all of the target servers where the application will be deployed. See "Install a Java EE Library" in Oracle Fusion Middleware Oracle WebLogic Server Administration Console Help.

  2. Copy the coherence.jar file to the WAR file's WEB-INF/lib directory.

  3. If you deploy the coherence-web-spi.war file as a shared library, create a shared library reference by adding the stanza illustrated in Example 2-9 to the weblogic.xml file in the WAR file's WEB-INF directory.

    Example 2-9 Library Reference for a Web Application

    <weblogic-web-app>
         ...
          <library-ref>
               <library-name>coherence-web-spi</library-name>
         </library-ref>
         ...
    <weblogic-web-app>
    

2.3 Scoping the Session Cookie Path

WebLogic Server and Coherence*Web handle session scoping and the session lifecycle in different ways. This can impact your decision to implement a single sign-on (SSO) strategy for your applications.

By default, WebLogic Server uses the same session ID in every Web application for a given client, and sets the session cookie path to "/". This is a requirement of the WebLogic Server default "thin" SSO implementation, which is enabled by default. By generating a session cookie with a path of "/", clients always return the same session ID in every request to the server. In WebLogic Server, a single session ID can be mapped to multiple session objects. Each Web application will have a different session object instance even though the session ID is identical (unless session sharing is enabled).

In contrast, Coherence*Web maps a session ID to a single session instance. This means that the behavior of having multiple session instances mapped to the same ID is not replicated by default if an application uses Coherence*Web. Since the session cookie is mapped to "/" by default, a single Coherence*Web session is shared across all Web applications. The default configuration in Coherence*Web is that all session attributes are scoped to a Web-application. For most purposes, this single session approach is transparent. The major difference of having a single session across all Web applications is the impact of session invalidation. If Coherence*Web is enabled and you invalidate a session in one Web application, then you invalidate that session in all Web applications that use that session instance. If your Web applications do not use "thin" SSO, then you can avoid this issue by scoping the session cookie to the Web application path.

Therefore, you have the following options regarding SSO:

One advantage of enabling thin SSO with Coherence*Web is that it will work across all Web applications that are using the same Coherence cluster for Coherence*Web. The Coherence cluster is completely independent from the WebLogic Server cluster. The thin SSO functionality can even span multiple domains by enabling cross-domain trust in the WebLogic Server security layer.

2.4 Securing Coherence*Web Deployments

To prevent unauthorized Coherence TCMP cluster members from accessing HTTP session cache servers, you can configure symmetric or asymmetric encryption filters. Coherence ships with two JCA-based encryption filters which can be used to protect the clustered communications for privacy and authenticity.

See "Using Network Filters" in the Developer's Guide for Oracle Coherence for information on implementing these filters.

2.5 Enabling Coherence*Web SPI for ColdFusion Applications

If your ColdFusion applications run on WebLogic server, follow these steps to enable Coherence*Web for session management.

  1. In the ColdFusion installer create a WAR version of ColdFusion.

  2. Follow the provided instructions for configuring WebLogic Server for ColdFusion.

  3. Extract the WAR into a directory for exploded directory deployment to WebLogic Server.

  4. Create a weblogic.xml file in the /WEB-INF directory of the exploded ColdFusion WAR. Specify the Coherence SPI as a <library-ref>.

    <?xml version="1.0"?>
    <weblogic-web-app xmlns="http://www.bea.com/ns/weblogic/weblogic-web-app"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.bea.com/ns/weblogic/weblogic-web-app http://www.bea.com/ns/weblogic/weblogic-web-app/1.0/weblogic-web-app.xsd">
       <library-ref>
          <library-name>coherence-web-spi</library-name>
       </library-ref>
    </weblogic-web-app>
    
  5. Copy the coherence.jar to the WEB-INF/lib directory of the exploded application.

  6. Copy cfusion.jar from WEB-INF/cfusion/lib to WEB-INF/.

  7. Start the WebLogic Server instance. Deploy the Coherence*Web SPI to WebLogic. The SPI is located at coherence\lib\coherence-web-spi.war in the Coherence distribution.

  8. Deploy the ColdFusion application to the WebLogic Server instance.

  9. Configure ColdFusion MX to use J2EE session management.

    1. Access the ColdFusion administration page at the following URL:

      http://<host>:<port>/coldfusion-context-root/CFIDE/administrator. 
      
    2. Select Memory Variables under Server Sessions and enable the Use J2EE session variables checkbox.

  10. Add your ColdFusion application under the exploded ColdFusion WAR.

    The application must have a Application.cfm file that specifies sessionmanagement="Yes", but should not configure the session using ColdFusion configuration (otherwise, exceptions are thrown). The Application.cfm should contain the following line:

    <cfapplication sessionmanagement="Yes">