Distributed Denial-of-Service (DDoS) is malicious attempt aimed to disrupt the traffic of a targeted server, service or network. It works by overwhelming the target or its infrastructure with a flood of Internet traffic. When the target or its infrastructure could not handle the surge in the traffic, it shuts down and locked out of normal access.
By using multiple compromised computer systems typically through bots or botnets, attacks will be launched to overwhelm the target. Regular traffic will clash with DDoS traffic resulting a deadlock whereby the target is slowly becomes out of service.
While the slowness of site or service is typically f=a symptom of DDoS attack, there could be other conditions such as odd traffic patterns at certain hours. In order to prevent DDoS attacks, the target need to build resiliency to deter the unforeseen meltdowns.
This free e-book shows examples of best practices to build resiliency (on AWS) to put an end to DDoS attacks.