Externally Monitoring the Web Servers
There is no doubt that it is imperative to monitor the request processing ability of the web server, the amount of data load that a web server can handle, or the key transactions to a web site hosted by the server. In fact, eG Enterprise addresses these critical internal monitoring needs using dedicated web server monitoring models (IIS, Apache Web, etc.), and its unique web adapter technology, all of which have been discussed previously. However, sometimes, administrators might only be interested in knowing whether the web server is available or not, and if so, how responsive it is to user requests. Some other administrators may not have access to the web servers to install agents, but may want to check its availability and responsiveness. To cater to such monitoring needs, eG Enterprise offers the exclusive, External Web model (see Figure 1). This model requires only an external agent, which employs native application-level protocols, to ascertain the availability and responsiveness of the web server.
Figure 1 : Layer model of the External Web Server
The Network test executed by the Network layer of Figure 1 is a typical external test that reports whether/not a healthy network connection exists between the agent host and the target web server. The Http test that executes on the Web Server layer emulates a user accessing a web server, and determines the availability, responsiveness, and the errors occurring on the web server, from an external perspective.
Please refer to the Monitoring Unix and Windows Server document for Network test and Monitoring Apache Web Server document for Http test.