istio リトライ

{
  "retry_policy": {
    "retry_on": "connect-failure,refused-stream,unavailable,cancelled,retriable-status-codes",
    "num_retries": 2,
    "retry_host_predicate": [
      {
        "name": "envoy.retry_host_predicates.previous_hosts",
        "typed_config": {
          "@type": "type.googleapis.com/envoy.extensions.retry.host.previous_hosts.v3.PreviousHostsPredicate"
        }
      }
    ],
    "host_selection_retry_max_attempts": "5",
    "retriable_status_codes": [
      503
    ]
  }
}