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Administering OracleAS Web Cache

This chapter explains how to perform basic administrative tasks for OracleAS Web Cache.

This chapter contains these topics:

• Starting and Stopping OracleAS Web Cache

• Propagating Configuration Changes to Cache Cluster Members

• Listing Popular Requests and Cache Contents

• Rolling Over Event and Access Logs

Starting and Stopping OracleAS Web Cache

Anytime the OracleAS Web Cache configuration is statically modified, you must stop and restart OracleAS Web Cache. Dynamic updates do not require a restart, as described in "Applying Static and Dynamic Configuration Changes". To start, stop, or restart OracleAS Web Cache, use either OracleAS Web Cache Manager or the opmnctl utility. The OracleAS Web Cache Manager enables you to start, stop, or restart the cache server process; the opmnctl utility enables you to start, stop, or restart the cache server process or admin server process, or both:

• The admin server process manages the OracleAS Web Cache Manager interface.

• The cache server process manages the cache.

The executable used for managing these process is webcached, which resides in $ORACLE_HOME/webcache directory on UNIX and the ORACLE_HOME\bin directory on Windows.

To initialize OracleAS Web Cache for the first time, use the opmnctl utility rather than the OracleAS Web Cache Manager to start the processes.

When you stop OracleAS Web Cache, all objects are cleared from the cache. In addition, all statistics are cleared.

Note: If you are running OracleAS Web Cache in a standalone environment (that is, you installed OracleAS Web Cache from a kit that included only this product; you did not install OracleAS Web Cache as part of an Oracle Application Server installation), you must use the webcachectl utility to administer OracleAS Web Cache processes. See Appendix C for information on using the webcachectl utility.

To start, stop, or restart the processes, use the steps in the following table:

Use OracleAS Web Cache Manager...

Use the opmnctl Utility...

To start, stop, or restart the cache server process: Start OracleAS Web Cache Manager. See: "Starting OracleAS Web Cache Manager" In the navigator frame, select Operations > Cache Operations. The Cache Operations page appears in the right pane. In the Cache Operations page, select the cache and click Start, Stop, or Restart. To perform the operation on one cache in a cache cluster: Select one cache, choose Selected Cache from the Operate On field and then click Start, Stop, or Restart. To perform the operation on all caches in a cache cluster: Choose All Caches from the Operate On field and then click Start, Stop, or Restart.

To start, stop, or restart both the admin server and the cache server processes: Determine the status of OracleAS Web Cache. From the command line, enter: opmnctl status OPMN generates a list of processes that are running. The following message indicates that the OracleAS Web Cache admin server (WebCacheA~) and the cache server (WebCache) are already running: Type |Pid |Status |ProcType |ProcSet |Ports ------+-----+------+-----------+------------+----- WebCa~|7550| Alive |WebCacheA~ | WebCacheA~ | WebCa~|7550| Alive |WebCache~ | WebCache~ | If the processes are not running, start the processes. From the command line, enter: opmnctl startproc ias-component=WebCache To stop the processes from the command line, enter: opmnctl stopproc ias-component=WebCache To restart the admin server and cache server processes from the command line, enter: opmnctl restartproc ias-component=WebCache See Also: "OPMN for Process Administration" for a complete list of the opmnctl commands

Propagating Configuration Changes to Cache Cluster Members

If you have made changes to the configuration of a cache cluster or if a cache cluster member is unreachable when OracleAS Web Cache tries to propagate the configuration to it, you must propagate the configuration to that cluster member when it is reachable again. Then, you must restart the cache.

OracleAS Web Cache keeps track of the configuration of all cluster members to ensure that all cluster members are using the same version of the configuration. It compares the configuration of the current cache (the cache to which you are connected) to that of the other cluster members.

To check that all cluster members are using the same configuration and to propagate the configuration, if necessary, perform following steps:

1. In the navigation pane, select Operations > Cache Operations.

   The Cache Operations page appears.

2. In the Operation Needed column of the table, check whether or not Propagate Configuration is noted for any cluster member.

   Propagate Configuration means that the configuration of the cluster member is different than the configuration of the current cache. You should verify that the configuration of the current cache is the most valid configuration before proceeding with propagation.

   If it is not, connect to the cache with the valid configuration and view the Cache Operations page.

3. For each cluster member that needs the configuration propagated, select the cache. Then, in the Operate On field, choose Selected cache and click Propagate. (Alternatively, to operate on all caches in the cluster, in the Operate On field, choose All caches. For the Interval, select Immediate, and then click Propagate.)

   OracleAS Web Cache propagates the configuration from the current cache to the selected cluster member. When the operation completes, the Operation Needed column in the Cache Operations page indicates that the cache needs to be restarted.

4. Restart all cluster members, either individually or all caches:
   • To restart one cluster member, select the cache. Then, in the Operate On field, choose Selected cache and click Restart.

   • To restart all caches in the cluster, in the Operate On field, choose All caches and specify an interval to stagger the times of the operations, and then click Restart.)

Listing Popular Requests and Cache Contents

With OracleAS Web Cache Manager, you can view a list of the most popular requests and a list of the contents of the cache, generating the following types of lists:

• A list of the URLs of the most popular requests received by the cache since the cache was last started. Popularity is calculated using two factors: how many times the request was made and how recently the requests were made. You can specify: only objects stored in the cache, only objects not stored in the cache, or all requests received by the cache.

  You specify the number of objects and OracleAS Web Cache Manager displays the list in the Popular Requests page.

• A list of the URLs of the objects currently in the cache.

  You specify a file name and OracleAS Web Cache writes the list of URLs to a file. You can use this list to verify that the cacheability rules are caching the objects that you want cached.

  Note: OracleAS Web Cache Manager lists only those objects that are valid. Although the cache may contain objects that are expired or that have been invalidated, those objects are not included in these lists.

Listing Popular Requests

To view the list of URLs of the most popular requests, perform the following steps:

1. In the navigation pane, select Monitoring > Popular Requests.

   The Popular Requests page appears in the right pane.

2. From the For Cache list, select a cache and click View. (More than one cache is listed only if you configured a cache cluster.)

3. In the List Most Popular Requests area, for Number of Documents, enter the number of URLs you want displayed.

4. For Filter Documents, select one of the following options:
   • All: All requests received by the cache.

   • Cached: Only those requests stored in the cache.

   • Not Cached: Only those requests not stored in the cache.

5. Click Update.

   OracleAS Web Cache Manager displays a table containing the list of URLs of requests since the cache was last started. The table contains the following columns:

   • Rank: A ranking, from 1 to 100, based on the score of the object. A rank of 1 represents the object with the highest score; that is, the most popular object.

   • Document Name: The URL of the object. The URLs may contain additional descriptive information, such as cookie or session information.

   • Size: The size of the object. The size is represented in bytes, kilobytes (KB), or megabytes (MB).

   • Cached: Whether or not the document is cached.

   • Cache Reason: The reason that the document is cached or not cached. Possible values are:
     • BY_SURROGATE_CONTROL_HEADER: Cached or not cached because of information in the Surrogate-Control response header.

     • BY_REFERENCE_TTL: Cached because of the nonzero value of the reference TTL (time-to-live parameters) specified in the ESI tag.

     • BY_VALIDATION: Cached because of the ETag response header.

     • BY_X_ORACLE_HEADERS: Cached or not cached because of information in the X-Oracle-Cache response header.

     • BY_CACHING_RULE: Cached or not cached because of the caching rule.

     • BY_HTTP_HEADERS: Cached or not cached because of information in the HTTP header.

     • BY_PRESEEDING: Cached because the documents were preseeded for use by End-User Performance Monitoring.

     • NC_NO_DIRECTIVE: Not cached because no directive or rule has stated that the document should be cached.

     • NC_SIZE_TOO_LARGE: Not cached because the document is larger than the size specified as the Maximum Object Size.

     • NC_COOKIE_MISMATCH: Not cached because the response contains a cookie that is not present in the request or that has a different value than the same cookie in the request.

   • Caching Rule: If a caching rule is associated with the object, this column displays a link to the Cacheability Rule Details page. That page shows the regular expression and site information for the URL.

   • Compressed: Whether or not the document is compressed.

Listing All Contents

You can also generate a list of the URLs of all of the documents currently stored in the cache:

1. In the navigation pane, select Monitoring > Popular Requests.

   The Popular Requests page appears in the right pane.

2. From the For Cache list, select a cache and click View. (More than one cache is listed only if you have a cache cluster.)

3. For List All Contents in Cache, click Export to File.

   The Export Cache Contents dialog box appears. It lists the file to which OracleAS Web Cache will write the URLs. By default, the file is written to the OracleAS Web Cache log directory and is named webcache_contents.txt.

4. To write the list to a different location, enter a complete file specification in the text box.

5. Click Submit.

OracleAS Web Cache writes the list of URLs to the text file you specified. Each time you generate the list, OracleAS Web Cache appends the data to the existing file. It lists the date that the data was appended to the file, followed by the URLs of the objects currently cached. The following example shows an excerpt of the webcache_contents.txt file:

Cache Contents at Wed Aug 22 11:47:03 2003
www.company.com:80/images/lnav/lnav_products.gif
www.company.com:80/images/rnav/rnav_red_line_1.gif
www.company.com:80/images/bullets_and_symbols/blk_line_bullet_10.gif
.
.
.
Cache Contents at Wed Aug 22 13:01:24 2003
www.company.com:80/images/white_spacer_xp.gif
www.company.com:80/images/white_spacer.gif
www.company.com:80/images/miniappsnet.gif
.
.
.

Rolling Over Event and Access Logs

In addition to configuring event and access log rollover frequency, as described in Chapter 12, you can also use OracleAS Web Cache Manager to immediately roll over event and access logs. During the rollover process, OracleAS Web Cache saves current log file to the log_file.yyyymmdd files and writes new log information to the log file.

To immediately rollover log files:

1. Start OracleAS Web Cache Manager, if it is not started.

   See: "Starting OracleAS Web Cache Manager"

2. In the navigation pane, select Operations > On-Demand Log File Rollover.

   The On-Demand Log File Rollover page appears.

3. To rollover event log files:
   1. From the Event Logs table, select an individual cache or click Select All to select all the caches.

   2. Click Submit.

4. To rollover access log files:
   1. From the Access Logs table, select an access log for a configured site or click Select All to select all the caches.

   2. Click Submit.