我有一个asp.net MVC网站,它正在消耗一个休息的api来接收它的数据.我正在使用异步任务执行请求,因为每个页面上可能有很多.经过一段时间的正常运行时间,网站在尝试接收数据时一直抛出以下错误.
我读到这可能是由于web.config上的最大连接设置,但增加这似乎并没有太大的区别.
我也使用缓存来减少api的负载.任务被缓存,结果可以在以后使用.
我发现解决这个问题的唯一方法是回收应用程序池.任何帮助将不胜感激.
/* Code from page_load */
var currenciesTask = ApiClient.GetAsync<CurrencyListWrapper>("currencies");
var blogArticleTask = ApiClient.GetAsync<BlogArticleListWrapper>("blog/articles","limit=10");
var SEOPageTask = ApiClient.GetAsync<SEOPageListWrapper>("SEOpages");
await Task.WhenAll(currenciesTask,blogArticleTask,SEOPageTask);
/* Code from data access later */
public class ApiClient : HttpClient
{
public static Task<T> GetAsync<T>(string operation,string query = null,bool cache = true)
{
// Check if task is in cache
string cacheName = null;
if (cache)
{
cacheName = String.Format("{0}_{1}_{2}",operation,query ?? String.Empty,App.GetLanguage());
var cachedTask = HttpRuntime.Cache[cacheName];
if (cachedTask != null)
{
return (Task<T>)cachedTask;
}
}
// Get data task
var task = GetAsyncData<T>(operation,query);
// Add to cache if required
if (task != null && cache)
{
App.AddToCache(cacheName,task);
}
return task;
}
public static async Task<T> GetAsyncData<T>(string operation,string query = null)
{
using (ApiClient client = new ApiClient())
{
string url;
if (query != null)
{
url = String.Format("{0}?{1}",query);
}
else
{
url = String.Format("{0}",operation);
}
var response = await client.GetAsync(url);
return (await response.Content.ReadAsAsync<T>());
}
}
}
解决方法
这是错的,
The task is cached so the result can be used later.
你应该缓存结果,而不是任务.在第一次执行结束时,您的HttpClient关闭,当您尝试检索缓存任务时,它将无法正常工作.
public class ApiClient : HttpClient
{
public static async Task<T> GetAsync<T>(string operation,App.GetLanguage());
T cachedResult = (T)HttpRuntime.Cache[cacheName];
if (cachedResult!= null)
{
return Task.FromResult(cachedResult);
}
}
// Get data task
var result = await GetAsyncData<T>(operation,query);
// Add to cache if required
if (result != null && cache)
{
App.AddToCache(cacheName,result);
}
return result;
}
public static async Task<T> GetAsyncData<T>(string operation,operation);
}
var response = await client.GetAsync(url);
return (await response.Content.ReadAsAsync<T>());
}
}
}
