apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/environment/PortalMetaDomainService.java/PortalMetaDomainService/reload
class PortalMetaDomainService:    public void reload() {
        for(PortalMetaServerProvider portalMetaServerProvider : portalMetaServerProviders) {
            portalMetaServerProvider.reload();
        }
        metaServerAddressCache.clear();
    }