Kubernetes v1.33: Streaming List responses

Kubernetes v1.33: Streaming List responses The problem: unnecessary memory consumption with large resources Streaming encoder for List responses Performance gains you'll notice Benchmark results Managing Kubernetes cluster stability becomes increasingly critical as your infrastructure grows. One of the most challenging aspects of operating large-scale clusters has been handling List requests that fetch substantial datasets - a common operation that could unexpectedly impact your cluster's stability. Today, the Kubernetes community is excited to announce a significant architectural improvement: streaming encoding for List responses. Current API response encoders just serialize an entire response into a single contiguous memory and perform one ResponseWriter. Write call to transmit data to the client. Despite HTTP/2's capability to split responses into smaller frames for transmission, the underlying HTTP server continues to hold the complete response data as a single buffer. Even as individual frames are transmitted to the client, the memory associated with these frames cannot be freed incrementally. When cluster size grows, the single response body can be substantial - like hundreds of megabytes in size. At large scale, the current approach becomes particularly inefficient, as it prevents incremental memory release during transmission. Imagining that when network congestion occurs, that large response body’s memory block stays active for tens of seconds or even minutes. This limitation leads to unnecessarily high and prolonged memory consumption in the kube-apiserver process. If multiple large List requests occur simultaneously, the cumulative memory consumption can escalate rapidly, potentially leading to an Out-of-Memory (OOM) situation that compromises cluster stability.