Setting up Content Download Caching

Content download caching (CDHC) is a new, optional feature that allows large content files to be streamed directly to the user's browser by an HTTP server. It is intended for use on larger deployments, where high numbers of concurrent downloads of large files could cause performance problems in WebSphere®. It is intended for use on larger deployments, where high numbers of concurrent downloads of large files could cause performance problems in WebSphere.

Before you begin

Use of content download caching has security implications. Access to cached content is authorized against the repository. However, cached content cannot be encrypted. P8 5.1+ supports encrypted storage areas. If an encrypted storage area is in use for object stores that store IBM Connections content, content caching should not be enabled.

1. Determine a suitable instance of IBM® HTTP Server. Install and configure a new instance if necessary. IBM HTTP Server does not need to be running on the same server as Filenet Configuration Service and can be shared with other server applications (such as Connections). However, both IHS and FNCS servers must have access to a single, shared, cache directory. The cache can be a network share. It should be writable by the FNCS server (WAS system user) but read-only on the IHS server. The mod_ibm_local_redirect module must be installed on the IBM HTTP Server. IBM HTTP Server must be configured with the following settings. Refer to Configuring HTTP Server to Connections for the FileNet Collaboration Services application for details.

   Alias /<url-alias> <path to cache share>
   
    
   
   <Directory "<path to cache share">
   
   Order Deny,Allow
   
   Deny from all
   
   Allow from env=REDIRECT_CDHC_CONTENT
   
   </Directory>
   
    
   
   <Location /dm>
   
   IBMLocalRedirect On 
   
   IBMLocalRedirectKeepHeaders X-LConn-Auth,Cache-Control,Content-Type,Content-Disposition,
   
   Last-Modified,ETag,Content-Language,Set-Cookie
   
   </Location>

   For example, if the cache network share is //csserver/cdhc and the URL alias is /cdhc_content. This example uses CDHC_CONTENT as the FNCS guard header. The IHS configuration would be as follows:

   Alias /cdhc_content //csserver/cdhc
   
    
   
   <Directory "//csserver/cdhc">
   
   Order Deny,Allow
   
   Deny from all
   
   Allow from env=REDIRECT_CDHC_CONTENT
   
   </Directory>
   
    
   
   <Location /dm>
   
   IBMLocalRedirect On 
   
   IBMLocalRedirectKeepHeaders X-LConn-Auth,Cache-Control,Content-Type,Content-Disposition,
   
   Last-Modified,ETag,Content-Language,Set-Cookie
   
   SetEnv CDHC_CONTENT true
   
   </Location>

2. Set the following optional configuration properties. They are mandatory for CDHC..
   • cdhc_isEnabled: set to “true”
   • cdhc_rootPath: set to the full path of the cache content directory. Can be on local disk or a network share.
   • cdhc_urlPath: set to the URL root that IHS is configured to use for cached content URLs.
   • cdhc_guardHeader: not strictly required for CDHC, but strongly recommended. Must match the extra header defined in the IHS config
   For example, using the sample values from the IHS section previously shown, the FNCS configuration would be as follows:

   cdhc_isEnabled=true
   
   cdhc_rootPath=//csserver/cdhc
   
   cdhc_urlPath=cdhc
   
   cdhc_guardHeader=CDHC_CONTENT