Monitoring software applications used to be an afterthought – when an outage happened, a check was put in place to monitor the functionality of the software or the status of part of the infrastructure where the software system ran. It had never been comprehensive, and the monitoring infrastructure grew organically. The first-generation monitoring tools were only designed to meet such a simple, reactive approach to rolling out monitoring.
The widespread use of the public cloud as a computing platform, the ongoing trend of deploying applications as microservices, and the delivery of Software as a Service (SaaS) with 24x7 availability made the operating of software systems far more complex than it used to be. Proactive monitoring became an essential part of DevOps culture as rolling out monitoring iteratively and incrementally is not an option anymore as the users expect the software systems to always be available. Software systems are now designed with observability in mind so that their workings can be exposed and monitored well. Both system and application logs are aggregated and analyzed for operational insights.
There is a large repository of monitoring applications now available to meet these new monitoring requirements both as on-premises and SaaS-based solutions. Some tools focus on a specific area of monitoring and others try to cater to all types of monitoring. It is common to use three or four different monitoring applications to cover all aspects of monitoring. Datadog, a SaaS monitoring solution, is emerging as a monitoring platform that can be used to build a comprehensive monitoring infrastructure in an enterprise. This book aims to introduce Datadog to a variety of audiences and help you to roll out Datadog as a proactive monitoring solution.