Working with Cache Management

Overview of the Sites Cache Summary Form

The Sites Cache Summary form lists the following basic data for each cache (values are estimates):

Total Count (total number of cached elements)
Memory Store Count (number of cached elements in memory)
Disk Store Count (number of cached elements on disk)
Cache Hits (number of cached elements retrieved from both memory and disk)
In Memory Hits (number of cached elements retrieved from memory)
On Disk Hits (number of cached elements retrieved from disk)
Cache Misses (number of times elements were not found in the cache)
Eviction Count (number of elements evicted from the cache)
Average Get Time (average number of milliseconds for retrieving an element)
Max Elements In Memory (maximum number of elements allowed in memory)
Max Elements On Disk (maximum number of elements allowed on disk)
Overflow to Disk (whether elements are written to disk when memory is full)

This form also provides the following options. They should be used with caution, especially on a delivery system, as they can impact the performance of your site.

Writing a cache's entire memory store to disk. This option can be particularly useful if WebCenter Sites is not set up to automatically write a cache's memory store to disk before shutting down.
Flushing a cache's entire memory and disk stores

Note:

If legacy page caching is enabled, cached page data is stored in the SystemPageCache table and information about the stored data is not displayed in the Summary window. This window also shows the Clear Page Cache button, which allows you to flush the stored data in System Page Cache and Co-Res SS Cache.

As System Page Cache is legacy, it must be enabled for use. This is done by disabling Ehcache by including the following as a JVM parameter of appserver:

-Dcs.useEhcache=false

To view and work with summary cache information:

In the General Admin tree, expand the Admin node, expand the System Tools node, expand the Cache Management node, expand the Sites Cache node, and then double-click Summary.

The Summary form appears.
Select the check box for the PageCache, Cache Dependencies, Asset Cache, or URL Cache and click Write To Disk to write the selected cache's entire memory store to disk.
Select the check box for the PageCache, Cache Dependencies, Asset Cache, or URL Cache and click Flush Cache to flush the memory and disk stores for the selected caches.

If you have enabled System Page Caching, a button labeled Clear Page Cache will appear underneath the Flush Cache button. Click Clear Page Cache to flush the SystemPageCache table and Co-Res SS Cache.

Working with Page Cache

This form lists statistics for each cached page, such as visit count, time of creation/last access/expiration, and dependencies. The table legend identifies which types of information are tracked: invalidated pages, updates to dependencies, and changes to the dependency generation count. The form also provides the following options:

Searching the cache for specific pages – Searches are CPU intensive and should be used with caution on a delivery system.
Flushing pages from the cache.
Viewing html information for pages.
Looking up page dependencies.

The view and work with items in the Page Cache:

In the General Admin tree, expand the Admin node, expand the System Tools node, expand the Cache Management node, expand the Sites Cache node, and then double-click Page Cache.

The Pages form is shown.
At the top of the form is the Search area. Select to search by Key, Expired Time, or by Dependency. If you enter an expired time to search by, use the forms mm/dd/yyyy or mm/dd/yyyy hh:mm:ss to enter a date and time. Click Search.
In the displayed items in the cache, click the header title to sort the items by that criteria.

All items are shown when initially loading the Pages form. The Search form limits what opens, making it easier to find items in the cache.
Underneath each item in the Key column, a view page details link opens. Click view page details to open a new window that shows the page's HTML information.
To flush selected assets from the cache, select the check box on the left side of each asset. Select the check box in the header to select all displayed assets. Click Flush Cache to flush the memory and stores of the assets.
To view the pages for a specific item within the cache, select the check box on the right side of each item. Select the check box in the header to mark all displayed dependencies. Click Page Lookup to show the pages for the dependency or dependencies.

Note that each item in cache can have multiple check boxes on the right side, reflecting multiple dependencies.

Note:

After WebCenter Sites is restarted, this form does not show page cache information until the cache engine is initialized. The cache engine is initialized when the first page or asset is requested.

Working with the Dependency Cache

This form lists the contents of the dependency cache and the generation count for each dependency. In addition, it provides the following options:

Searching the cache for specific dependencies – Searches are CPU intensive and should be used with caution on a delivery system.
Flushing dependencies from the cache
Looking up page dependencies

The view and work with items in the Dependency Cache:

In the General Admin tree, expand the Admin node, expand the System Tools node, expand the Cache Management node, expand the Sites Cache node, and then double-click Dependency.

The Dependencies form appears.
In the displayed items in the cache, click the header title to sort the items by that criteria.

All items are shown when initially loading the Dependencies form. The Search form limits what opens, making it easier to find items in the cache.
To flush selected assets from the cache, select the check box on the left side of each asset. Select the check box in the header to select all displayed assets. Click Flush Cache to flush the memory and stores of the assets.
To view the pages for a specific item within the cache, select the check box on the right side of each item. Select the check box in the header to mark all displayed dependencies. Click Page Lookup to show the pages for the dependency or dependencies.

Note:

After WebCenter Sites is restarted, this form does not show dependency cache information until the cache engine is initialized. The cache engine is initialized when the first page or asset is requested.

Working with the Asset Cache

This form lists statistics for each cached asset, such as visit count, time of creation/last access, and dependencies. The table legend identifies which types of information are tracked: invalidated assets, updates to dependencies, and changes to the dependency generation count. The form also provides the following options:

Searching the cache for specific assets. Searches are CPU intensive and should be used with caution on a delivery system.
Flushing assets from the cache
Looking up asset dependencies

The view and work with items in the Asset Cache:

In the General Admin tree, expand the Admin node, expand the System Tools node, expand the Cache Management node, expand the Sites Cache node, and then double-click Asset Cache.

The Assets form is shown.
At the top of the form is the Search area. Select to search by Key or by Dependency, and to show All or Any assets with the entered search value. Click Search.
In the displayed items in the cache, click the header title to sort the items by that criteria.

All assets are shown when initially loading the Assets form. The Search form limits what opens, making it easier to find items in the cache.
To flush selected assets from the cache, select the check box on the left side of each asset. Select the check box in the header to select all displayed assets. Click Flush Cache to flush the memory and stores of the assets.
To view the assets for a specific dependency within the cache, select the check box on the right side of each asset. Select the check box in the header to mark all displayed assets. Click Asset Lookup to show the dependencies.

Note:

After WebCenter Sites is restarted, this form does not show asset cache information until the cache engine is initialized. The cache engine is initialized when the first page or asset is requested.

Working with the URL Cache

All the Vanity URLs are cached after the resolution is done in a web page in inCache. The cache can be looked up and managed in the Cache Management node under System Tools.

The view and work with items in the URL Cache:

In the General Admin tree, expand the Admin node, expand the System Tools node, expand the Cache Management node, expand the Sites Cache node, and then double-click URL Cache.

The URLs form appears.
The Search area is at the top of the form. Select to search by Key or by Dependency with the entered search value. Click Search.
In the displayed items in the cache, click the header title to sort the items by that criteria.

All items are shown when initially loading the URL form. The Search form limits what opens, making it easier to find items in the cache.
To flush selected URLs from the cache, select the check box on the left side of each URL. Select the check box in the header to select all displayed URLs. Click Flush Cache to flush the memory and stores of the URLs.
To view the URL for a specific dependency within the cache, select the check box on the right side of each URL. Select the check box in the header to mark all displayed URLs. Click Asset Lookup to show the dependencies.

Viewing Cluster Information

If Sigar is configured, The Cluster Info form lists the name, URL, port, and GUID of each additional WebCenter Sites cluster member.

To view and work with cluster information:

In the General Admin tree, expand the Admin tab, expand the System Tools node, expand theCache Management node, expand the Sites Cache node, and then double-click Cluster Info. to show the Cluster Info form.