How to Tame Your Online Services

Online service systems, such as online banking systems and e-commerce systems, have been increasingly popular and important in our society. During operation of an online service, there can be a live-site service incident: an unplanned interruption, outage, or degradation in the quality of the service. Such incidents can lead to huge economic loss or other serious consequences. For example, the estimated average cost of one hour’s service downtime for Amazon.com is $180,000 [1].

Once a service incident occurs, the service provider should take actions immediately to diagnose the incident and restore the service as soon as possible. A typical procedure of incident management in practice (e.g., at Microsoft and other service-provider companies) goes as follows. When the service monitoring system detects a service violation, the system automatically sends out an alert and makes a phone call to a group of On-Call engineers to trigger an incident investigation. Given an incident, engineers need to understand what the problem is and how to resolve it. In ideal cases, engineers can identify the root cause of the incident and fix it quickly. However, in many cases, engineers are unable to identify or fix root causes within a short time, as it usually takes time to identify and fix the root causes, conduct regression testing, and re-deploy the new version to data centers. Thus, in order to recover the service as soon as possible, a common practice is to restore the service by identifying a temporary workaround solution (such as restarting a server component) to restore the service. Then after service restoration, identifying and fixing the underlying root cause for the incident can be conducted via offline postmortem analysis. Incident management has become a critical task for online services. The goal is to minimize the service downtime and to ensure high quality of the provided services. In practice, incident management of an online service heavily depends on data collected at runtime of the service, such as service-level logs, performance counters, and machine/process/service-level events. Such monitoring data typically contains information that reflects the runtime state and behavior of the service. Based on the data collected, service incidents can be detected and mitigated in a timely way.