This chapter describes Oracle Web Cache metrics.
Provides information about the performance metrics for the Web Cache instance.
This category provides performance-request metrics for the cache.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
This metric specifies the average number of seconds used to process a request during the current time period.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
If the number is low, then improve the connection between the cache and origin server, or upgrade the origin server computer.
This metric specifies the average number of requests served for each second during the current time period.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
If this number is high, then increase the capacity of this origin server from the Origin Servers page or load balance the requests among cache cluster members.
This category of metrics shows the resource usage of the computer with Oracle Web Cache.
This metric specifies the percentage of the CPU that is being used for Oracle Web Cache. As traffic increases, CPU utilization increases.
| Target Version | Evaluation and Collection Frequency | Upload Frequency | Operator | Default Warning Threshold | Default Critical Threshold | Alert Text |
|---|---|---|---|---|---|---|
| All Versions | Every 5 Minutes | After Every 3 Samples | > | Not Defined | Not Defined | CPU Utilization is %value%%% |
User Action
If the load is high, then consider upgrading the cache computer.
This metric specifies the percentage of system CPU time that is idle.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
If the load is high, then consider upgrading the cache computer.
The percentage of physical memory usage by applications other than Oracle Web Cache.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
If CPU usage is high, then consider upgrading the cache computer.
This metric specifies the total memory used by Oracle Web Cache.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
If the load is high, then consider upgrading the cache computer.
The metric specifies the amount of free physical memory, in megabytes, for the system.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
Other memory usage in MB
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
This metric shows the total memory of the host that has Oracle Web Cache.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
This metric specifies the percentage of total memory that is being utilized for cache memory.
| Target Version | Evaluation and Collection Frequency | Upload Frequency | Operator | Default Warning Threshold | Default Critical Threshold | Alert Text |
|---|---|---|---|---|---|---|
| All Versions | Every 5 Minutes | After Every 3 Samples | > | 80 | 90 | Memory Utilization is %value%%% |
This metric specifies the percentage of total memory that is being utilized for cache memory.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
This category shows the availability of the cache server process, which manages the cache.
This category shows the availability of the admin server process, which provides administrative access to the cache.
This metric indicates whether the admin server process for the Oracle Web Cache instance is up (1) or down (0). The admin server process provides administrative access to cache.
| Target Version | Evaluation and Collection Frequency | Upload Frequency | Operator | Default Warning Threshold | Default Critical Threshold | Alert Text |
|---|---|---|---|---|---|---|
| All Versions | Every Minute | After Every 60 Samples | = | Not Defined | 0 | The Oracle Web Cache admin server process is down |
User Action
If the admin server process is down, the context pane for the configuration pages displays an error, indicating that configuration is unavailable because the admin server process is down. To start the admin server process, from the Web Cache menu, choose Control, then Start Up, Shut Down, or Restart. See Starting and Stopping Oracle Web Cache for more information about starting Oracle Web Cache.
This metric indicates whether the cache server process for the Oracle Web Cache instance is up (1) or down (0).
| Target Version | Evaluation and Collection Frequency | Upload Frequency | Operator | Default Warning Threshold | Default Critical Threshold | Alert Text |
|---|---|---|---|---|---|---|
| All Versions | Every Minute | After Every 60 Samples | = | Not Defined | 0 | The Oracle Web Cache cache server process is down |
User Action
See Starting and Stopping Oracle Web Cache for more information about starting Oracle Web Cache.
This category provides performance metrics for each site.
This metric specifies the accumulated number of bytes that would be sent to clients if in-cache compression is disabled.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
If the number is low, then compression is not providing much benefit to the site. Try enabling compression in all caching rules to allow Oracle Web Cache to determine compressibility automatically based on the content type.
The metric specifies the size, in megabytes, of the objects currently stored in the cache. For a cache cluster member, this number is an aggregate of the owned and on-demand objects.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
No action user required. As Oracle Web Cache only cleans up invalid or expired objects on demand when memory is needed, this number may remain at a large value.
The metric specifies the accumulated number of error pages that Oracle Web Cache served to Web browsers since the cache was started.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
Oracle Web Cache serves error pages when there are problems fetching content from the origin server or when there ESI processing issues with the content. Even a small number can indicate an issue with site content or with origin server health.
This metric specifies the percentage of requests resolved by cache content. This percentage should be high, except when objects are being invalidated.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
If percentage of hits is low, then perform the following:
1. Review the caching rules configuration in the Caching Rules page.
2. In the Popular Requests page, select Non Cache Popular Requests from the Show Popular Requests list to view the most frequent misses.
3. In the results table, view the Caching Reason column for the most frequent URL requests that were not cached.
4. Configure caching rules to cache the popular requests. See Configure Caching Rules.
This metric specifies the number of objects cached.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
This metric specifies the current number of incoming open connections to the Oracle Web Cache server and outgoing open connections to the origin servers.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
If the number is close to the origin server connection limit, then set a larger capacity for the origin server from the Origin Servers page.
This metric specifies the accumulated number of requests denied by request filters.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
Any non-zero number may be an indication of an attack on the site or an issue with the configuration of request filters.
This category provides performance-request metrics for the origin servers. Please also review the metrics in the WebCache_timedHost category for additional metrics for origin servers.
This informational metric specifies the capacity you specified in the Origin Servers page for this origin server.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
This metric specifies the current number of connections from Oracle Web Cache that the origin server has open.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
This category provides performance-request metrics for the origin servers. Please also review the metrics in the WebCache_nontimedHost category for additional metrics for origin servers.
This metric shows the average amount of time for client requests forwarded by Oracle Web Cache to be resolved.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
If the latency appears high, then the administrator for the origin server or content source may need to add more system resources.
This metric shows the total time for client requests forwarded by Oracle Web Cache to be resolved, since the cache was started.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
If the latency appears high, then the administrator for the origin server or content source may need to add more system resources.
This metric specifies the accumulated number of client requests forwarded by Oracle Web Cache that the origin server has processed.
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 5 Minutes |
User Action
You can increase cache hit rate and lower the number client requests to the origin server by configuring caching rules for popular requests:
If percentage of hits is low, then perform the following:
1. Review the caching rules configuration in the Caching Rules page.
2. In the Popular Requests page, select Non Cache Popular Requests from the Show Popular Requests list to view the most frequent misses.
3. In the results table, view the Caching Reason column for the most frequent URL requests that were not cached.
4. Configure caching rules to cache the popular requests. See Configure Caching Rules.