There are ways in which you can tune the Multi-Channel Server (MCS) policy cache for better system performance.
MCS runs best when all of its device, layout, theme, asset group and component policies are cached in memory. The MCS configuration file, mcs-config.xml, contains policy cache configuration values. You should estimate how many layout, theme, and component policies that your installation will use, and then configure MCS to cache all of the policies.
By default, MCS is configured so that it does not time out any policies in the cache. You should keep the default policy cache timeout configuration, but this means that you must manually flush the policy caches at a controlled time if any policies are modified in the MCS database. You can use the MCS manager function to flush the policy caches. The other alternative is to restart the WebSphere® Portal application server.
See the topic Configuring Multi-Channel Server on WebSphere Portal for details about the procedure used to update the file mcs-config.xml.
See the topic Enabling and using the Multi-Channel Server manager function for information about enabling and using the MCS manager function to flush cached policies.
See the topic Configuring remote policy caches in the Multi-Channel Server information center for information about configuring the policy cache sizes, and about the required memory for each policy type.