Logging and Monitoring

Within the WC Manager tool, the Logging and Diagnostics section contains the following logs, which can be used for event and error tracking:

  • Event Logs. Properties for controlling event logging, location, verbosity , and rollover

  • Access Logs. Properties for controlling access logging, location, verbosity, and rollover

  • End- User Performance Monitoring. Options to turn on performance collection metrics

  • Diagnostics. Page to control the display of diagnostic information

For monitoring with WC Manager, there are five pages dedicated to monitoring statistics and performance located under Monitoring, which can be seen in Figure 19-15. They are

  • Web Cache Statistics. Performance metrics for overall cache performance and runtime statistics.

  • Health Monitor. Performance metrics page.

  • Origin Server Statistics. Metrics for requests processed and performance statistics for each origin server.

  • Popular Requests. Identifies the most popular requested content and if it's cached.

  • End-User Performance Analysis. Page to analyze response times for end users if this metric collection has been enabled.

Finally, WC has its own performance website separate from WC Manager that contains detailed statistics for WC and detailed memory statistics.

We won't examine all of these pages, but we'll explain some of the more interesting and useful pages.

Event and Access Logs

The Event and Access Log pages allow you to modify the settings for WC logging. Within each screen are options to modify these settings:

  • Log file location and name . $ ORACLE_HOME/webcache/logs and event_log and access_log are the default names .

  • Buffering. Logs are writing to in chunks of output for improved performance rather than a continual streaming of data into each log file.

  • Format style. Combined Log Format (CLF), WC log format, or a user-defined custom format.

  • Timestamp. Local or GMT time can be used.

  • Rollover Policy. How often does WC copy the file off to a different name and begin writing to a new empty file with the default log name? Do this regularly because writing to large files is a performance hit.

  • Verbosity. Event logs have verbosity settings of Warning, Notification, Trace, or Debug. The default setting is Notification. You shouldn't normally run in Trace or Debug mode unless you are actively tracking a problem because these modes do generate more log entries (performance hit) than the default Notification mode.

The logs are in a very similar format to the ones OHS creates. They're physically located in the $ ORACLE_HOME/webcache/logs directory for you to review manually.

Use the event_log to search for errors that occur during WC processing, startup, or shutdown.

The access_log can be used to determine what objects are being requested and from where. It's the same format as the OHS (Apache) access_log .

Web Cache Statistics

Web Cache Statistics is a very useful page that displays metrics for the WC configuration and statistics for the activity since it has been started. This page displays the following information:

  • Cache start time and duration

  • Number of documents currently in the cache and their total size in kilobytes

  • Total number of active connections

  • Amount of memory currently used by the cache and the total amount allowed

  • Total number of requests served , broken down into percentages for hits, misses, and compressed document hits and misses

  • Number of errors that have occurred

  • Total number of content invalidation requests and invalidated documents

This is one of the more useful pages for reviewing throughput and performance. The first few categories are shown in Figure 19-17.

image from book
Figure 19-17: Web Cache Statistics page

Some of the information in this page also appears in other pages such as the Health Monitor page. Regardless, the Web Cache Statistics page is an excellent place where you can identify performance and caching metrics for WC.

Origin Server Statistics

The Origin Server Statistics page is useful for determining how many requests are going to the origin server OHS as a cache miss , and for determining the resulting performance of that OHS server. The page identifies the origin server(s), the servers' uptime, the number of requests sent to the OHS, the time to process the request, and the number of sessions. This information is shown in Figure 19-18.

image from book
Figure 19-18: Origin Server Statistics page

Additionally, the page shows the number of errors that are currently occurring and the totals for each error category since startup time. This page also lists the current and total backlog of requests on the origin servers.

While this page can be used to monitor the number cache misses WC, we also like to use it to monitor the performance of OHS servers.

Popular Requests

The Popular Requests page is useful to gauge what content needs to be cached. It ranks the most requested content as both cached, not cached, and provides the size of the object. If the object is cached, it lists what rule forces it to be cached with a link to that rule, and whether or not the content is compressed. This is shown in Figure 19-19.

image from book
Figure 19-19: Popular Requests content page

In Figure 19-19 we've cached and are now serving from WC several image files (JPGs and GIFs). However, the JSPs themselves aren't cached. You'll explore caching and invalidation rules more in the next section.

Web Cache Detailed Statistics Monitor

WC has its own dedicated website outside of the WC Manager. To access the Web Cache Statistics Monitor, enter the following URL: http://mike.wessler.name:4002/ .

To access this page you're prompted for a username and password. The username is "administrator" and the password is the same as for WC Manager.

This page provides extremely detailed, real-time statistics for nearly every aspect of WC performance. It lists the number of requests and how those requests were handled (hit, miss, and so on) in multiple categories as shown in Figure 19-20.

image from book
Figure 19-20: Oracle Web Cache Detailed Statistics Monitor page

In addition to this page, you can also drill down from the Detailed Memory Statistics link.



Oracle Application Server 10g. J2EE Deployment and Administration
Oracle Application Server 10g: J2EE Deployment and Administration
ISBN: 1590592352
EAN: 2147483647
Year: 2004
Pages: 150

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net