There are a lot of reasons why proactive monitoring presents challenges in today and tomorrows IT environments.
We no longer have all Windows or all Linux Servers, nor do we have just a few applications. IT Environments over time become a Hodgepodge of a wide variety of physical hardware, operating systems, applications, and versions. Most likely there is also a combination of physical equipment, virtual environments, and cloud-based systems.
Virtualization is here to stay and for many good reasons that can be explored on the Web. The issue of visibility of business applications operating in virtualized environments becomes a must for proactive monitoring.
Cloud systems like AWS, Google Cloud, etc. are also growing rapidly, and as pricing continues to drop organizations will continue to migrate and proactive monitoring will also be a must.
With that being said a single monitoring system that can handle all different types of servers, hosts, databases, applications, network devices, and cloud systems has become an ongoing proactive project for IT Organizations faced with these challenges.
In my opinion one system will not always be practical or desired, but a half dozen or more is just not cost effective and not easily managed, especially during implementation and ongoing maintenance or changes.
At the minimum a good solution for many is a solid internal monitoring system like NagiosXI; which when properly configured can keep a close watch of a wide variety of physical and virtual systems and applications. I also recommend a good external monitor (outside your network environment) to check website availability and speed, DNS propagation, email checks, and any other important customer facing applications and services you may provide.
With more aggressive and disruptive security attacks, complex databases, constant upgrades and patches, application bugs/vulnerabilities, no wonder IT Organizations become reactive instead of proactive. The goal is to stay one step ahead in the rapid and ever changing landscape of Technology. For all these reason and more, accurate and reliable proactive monitoring of all your critical systems in your infrastructure is an IT organization best way to be proactive whether on offense or defense.
What does this all mean to the customer? Means we are monitoring our services 24/7 day and night. It means less downtime, more secure transactions and faster load times. We are an online business and in order to stay successful you have to monitor and constantly update your infrastructure to stay ahead of the curve.