Istio has virtual service for pods with istio-proxy side cars but what istio ingress-gateway pod itself , how to enable retries from istio ingressgateway pod. Use case is that i am seeing 503 error in case of downscaling and want ingressgateway to retry for specific destination
1 Answers
Basically, Istio mesh represents ingress communication model between external Load Balancer through istio-ingressgateway
and logical traffic management CRD components, which define a network routes, Authentication/Authorization aspects and service-to-service interactions.
Istio Gateway as the major contributor with an edge istio-ingressgateway
service describes essential information about ports and protocols for HTTP/HTTS/TCP connections that are entering the service mesh and a way how to manage the further routing scenarios, therefore istio-ingressgateway
does not decide itself about network traffic workflow and target application endpoints.
Retries concept in Istio is actually enclosed in routing rules and composed within VirtualService resource, showing us the main principle of network request re-attempts and their timeouts in case of initial call's failure.
When Istio istio-ingressgateway
Pod starts it retrieves the discovery data about Envoy sidecars from Pilot, approaching the desired state through pilot-agent
specific flags.
However, I couldn't determine the reported 503 error, during down-scaling istio-ingressgateway
replicas in Istio 1.3.