A data processing method, comprising: using computing apparatus, causing instantiating a plurality of baseline application instances that are running a first version of software, and one or more canary application instances that are running a second version of the software; using computing apparatus including a load balancer, causing selectively routing a first proportion of incoming requests to the baseline instances, and routing a second proportion of the incoming requests to the canary instances; monitoring the plurality of canary instances to collect performance data for performance metrics; determining that the performance data indicates a negative performance issue, and in response thereto: using computing apparatus, automatically updating the first proportion to be larger and updating the second proportion to be smaller, and then reconfiguring the load balancer based upon the first proportion and the second proportion; terminating one or more of the canary application instances.