private void onOriginConnectFailed(Throwable cause) {
        passport.add(PassportState.ORIGIN_CONN_ACQUIRE_FAILED);
        if (!context.isCancelled()) {
            errorFromOrigin(cause);
        }
    }
Override to track your own request stats.
zuul-core/src/main/java/com/netflix/zuul/filters/endpoint/ProxyEndpoint.java