Some embodiments of the invention provide a method for monitoring and adjusting a service chain that includes several services to perform on data messages passing through a network. For a service chain implemented by a set of service paths each of which includes several service nodes that implement the services of the service chain, the method receives, from a set of service proxies, operational data relating to data transmission characteristics of a set of operational service nodes. The method analyzes the data transmission characteristics. In response to the analysis of the data transmission characteristics, the method alters the set of service paths implementing the service chain.