Service Mesh and API Management

A colleague of mine has been looking at a complete development platform transformation to better meet the needs of the organisation.  There are some very lofty goals he wants to achieve, and we've had some very interesting (and exciting) discussions on where he wants to head. 

One of the discussions we have had is in relation to the management of services and the difference between Service Mesh solutions and API Management.  On the surface there are a lot of overlaps between the two concerns, and it isn't immediately obvious what API Management solutions offer that Service Mesh solutions don't.  

Breaking it down, the Service Mesh should be responsible for ensuring your services are available.  Capabilities such as rich security models, automatic scaling, monitoring and control dashboards, and infrastructure abstraction are also core features of Service Mesh platforms.  Solutions like Istio can also provide advanced cross-cutting concerns such as service redirection, logging and caching without having to incorporate those capabilities in the underlying services.

API Management on the other hand is about how those services are exposed to consumers.  This is aimed at ensuring the people who need to use your services can access them, and have the necessary tools to use them.  Like a Service Mesh, API Management is concerned about access security, service failover and monitoring, but are not responsible for controlling the services themselves.  Instead the API Management layer is responsible for managing which APIs are accessible to which consumers, transforming the services to meet consumer constraints, setting service access limits, and defining billing and utilisation policies.

API management wasn't something my colleague had looked into, but it is an important part of defining how the services would be accessed.  The industry has a tendency to equate "API Management" with "Monetisation" and it is easy to discount API Management when looking at the capabilities of Service Mesh solutions, but when you consider the key differentiation between managing services and managing consumers, there's definitely value in looking at both.