...
The caching module of XperienCentral stores a timestamp in the timestamp database for each cached web page. This timestamp is needed in order to determine whether the web page needs to be regenerated or whether it can be retrieved from the cache. For high volume websites, the number of web page requests per second can be so high that even the relatively simple task of performing one SQL query to retrieve this timestamp from the database can cause a bottleneck. If this exceeds 500 milliseconds, it may indicate a performance issue.
To prevent timestamp retrieval from becoming a bottleneck, timestamps can be cached in memory for <n> milliseconds. Note that this also causes a delay of <n> milliseconds; during the <n> milliseconds, modified web pages will not be regenerated. It is recommended that you set timestamp caching to at least 5000 milliseconds (5 seconds). If you set timestamp caching to fewer than 5000 milliseconds, this can cause database bottlenecks especially for websites that experience a large number of page requests.
Timestamp caching is configured in the XperienCentral Setup Tool. Navigate to the "Frontend System Settings" section of the [General configuration] tab:
Lowering Page Response Times
Page response time performance for pages returned from the cache as well as pages generated by the Page Generator is measured in the following way:
| Indicator | Value | |||
|---|---|---|---|---|
| Largest page response time | milliseconds | Less than or equal to 1000 | Between 1000 and 4999 | 5000+ |
| Average response time | milliseconds | 0-99 | 101-499 | 500+ |
Large Response Times for Individual Pages
...
Query execution time is measured in the following way:
| Indicator | Value | |||
|---|---|---|---|---|
| Slowest Queries | milliseconds | 500 | Between 500 and 2000 | 2000+ |
Query execution time that exceeds 500 milliseconds may indicate a performance issue. The list of the slowest queries contains both internal XperienCentral queries as well as queries that have been developed especially for your web site. If a query that you have developed is especially slow compared to other queries or is consistently slow, you might want to examine it carefully to see whether it is possible to restructure it for greater efficiency.
...
Average query response time is measured in the following way:
| Indicator | Value | |||
|---|---|---|---|---|
| Average query execution time | milliseconds | 0-500 | 501-1999 | 2000+ |
If the average query execution time is higher than 501 milliseconds, it could indicate a fundamental problem with the performance of the database that XperienCentral is using. If other applications are using the same database as XperienCentral, this can cause the average query execution time to increase. If you consistently experience high average query execution times, you should investigate how the database you are using for XperienCentral is configured and whether it is functioning correctly/optimally.
...
The average cache ratio is measured in the following way:
| Indicator | Value | |||
|---|---|---|---|---|
| Average cache ratio | percent | 10+ | between 1 and 9 | less than 1 |
A cache ratio that is less than 10 indicates that XperienCentral is having to generate a large number of pages instead of retrieving them from the cache. This can be because:
...
The XperienCentral debug options are useful during the website development phase but should not be enabled on a live website because they can slow down performance. The possible statuses of the debug option in the dashboard are:
| Indicator | ||
|---|---|---|
| Debug options | All debug options are disabled. | One or more debug options is enabled. |
To enable/disable the XperienCentral debug options that affect performance, run the Web Manager Setup Tool. On the [General configuration] tab, navigate to the "Development_Settings". Clear the checkbox for "enable_debug_messages". Note: In a production environment, the setting "enable_view_resolve_cache" should be selected.
...
The level at which you log messages has a direct effect on system performance. Each time a system event is logged, a small performance hit occurs. Logging messages of type SEVERE affects the system the least whereas logging at the INFO level can cause the system to slow down due to the sheer volume of messages that are written to the log. The effect that the logging level has on XperienCentral performance is indicated as follows.
| Indicator | |||
|---|---|---|---|
| Log level | SEVERE | WARNING | INFO |
To change the log level, follow these steps:
...
In addition to the four default tabs, you can develop and extend the XperienCentral Performance Dashboard using custom WCB's. See the WCB Tutorial document available from the GX Connect website.