Synthetic monitoring

Synthetic monitoring (also known as "active monitoring") is website monitoring that is done using a web browser emulation. Behavioral scripts (or paths) are created to simulate an action or path that a customer or end-user would take on a site. Those paths are then continuously monitored at specified intervals for availability and response time measures.

Synthetic monitoring is valuable because it enables a webmaster to identify problems and determine if his website or web application is slow or experiencing downtime before that problem affects actual end-users or customers. This type of monitoring does not require actual web traffic so it enables companies to test web applications 24x7, or test new applications prior to a live customer-facing launch.

Because synthetic monitoring is a simulation of typical user behavior or navigation through a website, it is often best used to monitor commonly trafficked paths and critical business processes. Synthetic tests must be scripted in advance, so it is not feasible to measure performance for every permutation of a navigational path an end-user might take. This is more suited for passive monitoring. Synthetic testing is useful for measuring availability and response time of critical pages and transaction (how a site performs from all geographies) but doesn't monitor or capture actual end-user interactions.

Passive monitoring is also known as - real user monitoring - and can be used to monitor actual user sessions on web sites in order to detect and capture errors and performance slowdowns. Passive monitoring products are usually based on hardware devices that sit inside the firewall and capture traffic as it enters.

References: [http://www.gomez.com/products/passive-monitoring.php]