const microCache = LRU({
 max: 100,
 maxAge: 1000 // 重要提示：条目在 1 秒后过期。
})

const isCacheable = req => {
 // 实现逻辑为，检查请求是否是用户特定(user-specific)。
 // 只有非用户特定 (non-user-specific) 页面才会缓存
}

server.get('*', (req, res) => {
 const cacheable = isCacheable(req)
 if (cacheable) {
 const hit = microCache.get(req.url)
 if (hit) {
  return res.end(hit)
 }
 }

 renderer.renderToString((err, html) => {
 res.end(html)
 if (cacheable) {
  microCache.set(req.url, html)
 }
 })
})

const renderer = nuxt.renderer;
const renderRoute = renderer.renderRoute.bind(renderer);
renderer.renderRoute = function(route, context) {
 // hopefully cache reset is finished up to this point.
 tryStoreVersion(cache, currentVersion);

 const cacheKey = (config.cache.key || defaultCacheKeyBuilder)(route, context);
 if (!cacheKey) return renderRoute(route, context);

 function renderSetCache(){
  return renderRoute(route, context)
   .then(function(result) {
    if (!result.error) {
     cache.setAsync(cacheKey, serialize(result));
    }
    return result;
   });
 }

 return cache.getAsync(cacheKey)
  .then(function (cachedResult) {
   if (cachedResult) {
    return deserialize(cachedResult);
   }

   return renderSetCache();
  })
  .catch(renderSetCache);
};

ab -n 4000 -c 50 -s 120 -r http://localhost:3000/