private static void warnStreamingAttributes(String cluster, Schema schema, DeployLogger logger) {
        for (ImmutableSDField sd : schema.allConcreteFields()) {
            if (sd.doesAttributing()) {
                warnStreamingAttribute(cluster, schema, sd, logger);
            }
        }
    }
Warn if one or more attributes are defined in a streaming search cluster SD.
config-model/src/main/java/com/yahoo/vespa/model/application/validation/StreamingValidator.java