Performance Implications

The gateway solves the problems listed earlier in this chapter by taking work off the clients. That work does not disappear. It moves to one component that every request has to pass through, and this lesson covers what that costs.

What Can Go Wrong

1. A single point of failure. If the gateway is down, no client can reach any service, even though every service is healthy. Run several instances behind a load balancer, spread across machines, and monitor it as closely as any service behind it.

2. A bottleneck. Every request passes through it, so its capacity is the system's capacity