From the original article: > A quick note on our migration strategy It can be risky to switch load balancing strategies all at once. This is why we enable serv

From the original article: > A quick note on our migration strategy It can be risky to switch load balancing strategies all at once. This is why we enable service owners to configure multiple load balancing strategies for a service in Robinhood. The LBS writes the weighted endpoints list generated by different strategies into different entries in the routing database. At Dropbox, we have a percentage-based feature gate, so we implement a mixed strategy where clients use the weighted sum of the weights generated by two load balancing strategies as the endpoint weight. For example, endpoint A might be weighted at 100 based on PID-based load balancing and 200 based on simple round-robin strategy. If we set the feature gate to 30% for PID-based load balancing, the weight of endpoint A becomes 100*0.3 + 200*0.7 = 170. This way, we can ensure that every client sees the same weight assignment for endpoints while gradually migrating to the new load balancing strategy. https://dropbox.tech/infrastructure/robinhood-in-house-load-balancing-service https://dropbox.tech/infrastructure/robinhood-in-house-load-...