A monitoring service may receive, from a plurality of service providers, log information pertaining to access calls made by service consumers to services or APIs provided by the service providers. The monitoring service aggregates and analyzes the log information for use in monitoring performance of the services, identifying anomalies, and the like. In some instances, the monitoring service may identify multiple services that are behaviorally interrelated based on at least one performance metric, and may group these services together into service groups for monitoring purposes. A service relationship model may be generated for each of the service groups that predicts how each service will behave relative to the other services in the service group. The monitoring service may monitor performance and use of the services based, at least in part, on the one or more service groups and the service relationship model for each group.