ded.</li><li>Unlike virtual service merging, destination rule merging works in both sidecars and gateways.</li></ol><h2 id=avoid-503-errors-while-reconfiguring-service-routes>Avoid 503 errors while reconfiguring service routes</h2><p>When setting route rules to direct traffic to specific versions (subsets) of a service, care must be taken to ensure
that the subsets are available before they are used in the routes. Otherwise, calls to the service may return
503 errors during a reconfiguration period.</p><p>C