I got this error recently from an application deployed on Kubernetes. This application works fine when the request data size is small and it fails when the request size is large. This can be fixed easily by increasing the request payload size limit in the ingress controller. This is a property of the nginx. Sample ingress.yml is given below.
apiVersion: extensions/v1beta1 kind: Ingress metadata: name: my-app annotations: nginx.ingress.kubernetes.io/proxy-body-size: "50m"
Here we have modified the body size to 50 MB. The default value of this property is 1 MB.