Constant Web Change Notifications

Constant Web Change Notifications

 

Customers continue to open Customer Care cases regarding the receipt of notiifcations informing of Web Change.

 

The Notification says:

Disregard this message if you were aware of the change. Otherwise you may want to check that your site has not been corrupted or compromised.
If you believe that you have received this message in error please review our change-detection methods at:

http://www.alertsite.com/faq.shtml#q14

These notifications are received because in AlertSite 1.0 UI under Manage Site/Manage Transaction the setting Notify on Content Change? is set to YES. We advise this to be set to NO.

 

There are two Knowledge Base articles on this subject:

Question What is Notify On Content Change?

This is a feature that we do not recommend unless your web page is intended to be completely static.

This is a legacy hold-over from the first days of AlertSite when web site pages were simple and HTML byte count was static. This feature will only send the information that there has been a Web Change when the number of bytes has changed since the previous measurement. It does not provide what the byte difference is, or what objects, etc., caused the change. It only says Web Change and refers to http://www.alertsite.com/faq.shtml#q14

 

This will cause a notification to be sent if a GET to a pixel tracker was present on the last measurement is not present on the next.

 

If a measurement had a byte count for a page: Total Length: 11,314,127 bytes, and the next measurement had a byte count of 11,314,126, a Web Change notification would be sent out. It would not provide information that the byte count changed.

 

When used on a transaction: “This is for the last event only” means:

If there is a multiple Action transaction, this feature would only check the byte count difference for the very last event of the transaction. (Each Action may have several events. This only checks if the byte count has change on the final event.)

 

Who is notified when this option is enabled?

This notification goes out as an availability-type notification. It would go to every notifier in a group.

 

We again advise to not use this feature as it will result in a notification every few minutes, since modern web site content (byte count) is very dynamic and not static. It is intended for a static web page only.

Question How Does Notify On Content Change Function?

AlertSite checks either the "Last-Modified" or "Content-Length" header field to identify content change of any HTTP(S) site based monitors i.e. Web Site, Secure Web Site, Web Site API, or Secure Web Site API.

For a DejaClick monitor, the content change detection only relies on the standardized "Last-Modified" header but not the "Content-Length" filed.

Please note that the only information provided is that there was a change in content. It does not provide what changed, i.e. the byte count or byte count difference, or the Last-Modified information is not provided.

This feature was implemented in the 1990s when base page HTML was very basic.