Discovery: What Is It?

[SlightlyLoony]

This blog is all about Discovery (and related things like the CMDB), so I think it's appropriate for the first post to answer this question: what exactly does the Discovery product do?

Most fundamentally, Discovery finds the devices and computers connected to your enterprise's network, figures out what they are, and collects information about them. The ability to find, classify, and explore most common kinds of devices and computers are all built right into Discovery: workstations, servers, routers, and much more. For computer systems, Discovery will also find all the software that's running in that computer. In each new version of Service-now we add even more devices. For example, the next release will include uninterruptible power supplies (UPSs).

Discovery doesn't use any magic or secret sauce to gather this information -- just standard tools. The same tools, in fact, that IT professionals use every day. For example, with Unix or Linux servers, Discovery primarily uses SSH to execute standard commands. To explore Windows computers, Discovery uses Windows Management Instrumentation (WMI). On network gear, Discovery uses Simple Network Management Protocol (SNMP) to find out about them. Essentially Discovery automates the use of these tools to do exactly the same thing an IT professional would do to find the same information.

Once Discovery has found the devices and computers on your enterprise's network, it will then find out about the relationships those systems have with each other. It does this by finding the network conversations between systems, and then figuring out which software on each computer is having that conversation. For example, you suppose you have a server running an accounting package, and that accounting package uses a database that's running on a different server. Discovery will see that network conversation (a TCP connection), and it will know that the accounting package is initiating TCP connections to the database server. Discovery translates this connection information into a formal relationship between that accounting package and the database server -- which means that now your Service-now software will know that the accounting package depends on the database server. These relationships are on-screen in every CMDB item, and with one click you can get a graphical map of them.

That's the basics on Discovery! Of course there are many details, and those details will be the subject of future posts to this blog. Please feel free to ask questions by posting comments to this (or any) post...