Overview
WEXAL® Page Speed Technology (hereinafter referred to as "PST") generates optimization strategies by Strategic AI "David" according to the browser environment. The PST plug-in on the web server rewrites the HTTP response content after web server rendering.
The optimization strategy is a set of directions for each web page (URL) on how to rewrite the HTTP response to match the environment of the requesting browser.
Modifing PST Configurations
Optimization strategies are automatically generated by Strategic AI "David", but you can also modify optimization strategies. The following methods are available for setting up optimization strategies;
Setup in PST Manager
You can change the optimization strategy settings in PST Manager by selecting the profile and "Mode" on the dashboard. Refer to "PST Manager" for more information.
Unless there is a particular reason not to, we recommend using PST Manager to modify the settings.
Setup in the PST Configuration File
You can change to "Developer-mode" (not using Strategic AI "David") by editing settings in the PST configuration file. In Developer-mode, Strategic AI "David" does not generate optimization strategies. Refer to the "PST Configuration File" for more information.
Generating Optimization Strategies
Optimization strategies are generated for each web page (URL) according to the environment of the requesting browser.
Therefore, different optimization strategies are generated for each web page (URL). Also, even for the same web page (URL), different optimization strategies are generated for different browser environments.
Optimization strategies will not be generated again for a certain period of time. The default setting length is 1 hour.
Optimization strategies will not be generated again if a request is from the same web page (URL) or the same browser environment within the set time period. If a request is made from a different browser environment, and if the set time period has passed, optimization strategies for that browser environment will again be generated. Similarly, if a request is made from the same browser environment to a different web page (URL), the optimization strategy for that web page's browser environment will be generated again if more than the set time period has passed since the last strategy was generated.
If the optimization strategy settings have been changed, the new settings will be reflected when the optimization strategy is generated. (Note: Changes to the optimization strategy settings are not reflected until the optimization strategy is generated again.)
You can check the status of the optimization strategies in the following ways.
Check with the HTTP Header
When PST is enabled, the optimization strategy status will be output in the "x-pst-dynamic" header. Refer to "HTTP Response Headers" for more information.
Check with the Web Server Access Log
When PST is enabled, the optimization strategy status will be output to the web server access log. Refer to "Logs" for more information.
Applying Optimization Strategies
If the web page (URL) has an optimization strategy that matches the requesting browser's environment, the optimization strategy will be applied.
There is no optimization strategy on the server when accessing a web page (URL) for the first time. Therefore, no optimization strategy will be applied. Similarly, if the same web page (URL) is accessed from a new browser environment, no optimization strategy will be applied because no optimization strategy is found on the Server.
If a previous web page (URL) is accessed and the optimization strategy is found on the Server, the previously generated Optimization Strategy will be applied. Note that changes to the optimization strategy settings are not reflected until optimization strategies are again generated.
You can check the status of the optimization strategy in the following ways.
Check with the HTTP Header
When PST is enabled, the optimization strategy status will be output in the "x-pst-dynamic" header. Refer to "HTTP Response Headers" for more information.
Check with the Web Server Access log
When PST is enabled, the optimization strategy status will be output to the web server access log. Refer to "Logs" for more information.
Removing Optimization Strategies
In principle, optimization strategies are not removed from the Server. The most recently generated optimization strategy is stored in the Optimization Strategy Database ready to apply to the web page (URL) the next time.
Even if the web page (URL) is changed and the web page is no longer accessible, the optimization strategy will still be stored. Therefore, when a web page is accessed that has completely different contents but the same URL, the last optimization strategy generated will be applied. In this case, an optimization strategy modified to the new content of the web page will be generated on the first access after the content has been changed. Then, the next time the web page (URL) is accessed (and thereafter), the newly generated optimization strategy will be applied.
You can initialize the optimization strategy if the number of unused web pages (URLs) increases or if the component of web pages (URLs) is significantly changed. Initialization of an optimization strategy is executed with the "pst initdb" command. Refer to "PST Commands" for more information.