Displaying cache information
Use this task to monitor the activity of the dynamic cache service.
About this task
The dynamic cache monitor is an installable web application that displays simple cache statistics, cache entries, and cache policy information for servlet cache instances.
The
cache monitor provides information about the cache in the servant
to which your browser connects to interact with the monitor. In an
environment with multiple servants, the cache monitor provides a partial
view of caching activity.
Procedure
- Use the administrative console to install the cache monitor
application from the app_server_root/installableApps directory.
The name of the application is CacheMonitor.ear. For more information about installing applications, refer to
the Installing application files with the console topic. Install the
cache monitor onto the application server that you want to monitor.
Access the cache monitor on the application port, which uses 9080 as its default port number.
The cache monitor application must be installed on the default_host (908x).
- Configure the web container transport chain and host alias
for the server with cache monitor installed.
- Add a host alias for the port your server is using. Click Environment > Virtual hosts > host_type > Host aliases and create a new Host name and Port to add to the list. Creating a host alias enables you to access the cache monitor using http://your_host_name:your_port_number/cachemonitor
Tip: You can find the port number in the SystemOut.log file. Look for message TCPC0001I or SRVE0171I.Note: This topic references one or more of the application server log files. As a recommended alternative, you can configure the server to use the High Performance Extensible Logging (HPEL) log and trace infrastructure instead of using SystemOut.log , SystemErr.log, trace.log, and activity.log files on distributed and IBM® i systems. You can also use HPEL in conjunction with your native z/OS® logging facilities. If you are using HPEL, you can access all of your log and trace information using the LogViewer command-line tool from your server profile bin directory. See the information about using HPEL to troubleshoot applications for more information on using HPEL. - Access the cache monitor using a web browser and the URL http://your host_name:your port_number/cachemonitor, where your port_number is the port associated with the host on which you installed the cache monitor application.
- Verify the list of cache instances that are shown. For
each cache instance, you can perform the following actions: Tip: You must select the servlet cache instance that you want to monitor. If you do not use servlet cache instances by using <cache-instance> tags in your cachespec.xml file, all the content is in the baseCache instance.
- View the Statistics page and verify the cache configuration and cache data. Click Reset Statistics to reset the counters.
- View the Cache Policies page to see which cache policies are currently loaded in the dynamic cache. Click a template to view the cache ID rules for the template.
- View the Cache Contents page to examine the contents that are currently cached in memory.
- View the Edge Statistics page to view data about the current ESI processors configured for caching. Click Refresh Statistics to see the latest statistics or content from the ESI processors. Click Reset Statistics to reset the counters.
- View the Disk Offload page to view the disk configuration, statistics, and the content that is currently off-loaded from memory to disk.
- Use the cache monitor to perform basic operations on data
in a cache instance.
- Remove an entry from cache
- Click Invalidate when viewing a cache entry.
- Remove all entries for a certain dependency ID
- Click Invalidate when viewing entries for a dependency ID.
- Remove all entries for a certain template
- Click Invalidate when viewing entries for a template.
- Move an entry to the front of the Least Recently Used queue to avoid eviction
- Click Refresh when viewing a cache entry.
- Move an entry from disk to cache
- Click Send to Memory when viewing a cache entry on disk.
- Clear the entire contents of the cache
- Click Clear Cache while viewing statistics or contents.
- Clear the contents on the ESI processors
- Click Clear Cache while viewing ESI statistics or contents.
- Clear the contents of the disk cache
- Click Clear Disk while viewing disk contents.
Subtopics
Cache monitor
Cache monitor is an installable web application that provides a real-time view of the current state of dynamic cache. You use it to help verify that dynamic cache is operating as expected. The only way to manipulate the data in the cache is by using the cache monitor. It provides a GUI interface to manually change data.Dynamic cache MBean statistics
The dynamic cache service provides an MBean interface to access cache statistics.Dynamic cache PMI counter definitions
The dynamic cache statistics interface is defined as WSDynamicCacheStats under the com\ibm\websphere\pmi\stat package.Tuning dynamic cache with the cache monitor
Use this task to interpret cache monitor statistics to improve the performance of the dynamic cache service.


File name: tdyn_servletmonitor.html