C＃Neo4jClient TaskCancelled异常

Question

我使用Neo4jClient并获得其中发生相当随机的异常使一个相当长的查询Neo4j的数据库。如何解决这一问题？

System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> System.Threading.Tasks.TaskCanceledException: A task was canceled.



--- End of inner exception stack trace ---
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at Neo4jClient.GraphClient.<>c__DisplayClass3.<SendHttpRequestAsync>b__2(Task`1 requestTask) in c:\TeamCity\buildAgent\work\f1c4cf3efbf1b05e\Neo4jClient\GraphClient.cs:line 149
   at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at Neo4jClient.GraphClient.<>c__DisplayClass1b`1.<Neo4jClient.IRawGraphClient.ExecuteGetCypherResultsAsync>b__1a(Task`1 responseTask) in c:\TeamCity\buildAgent\work\f1c4cf3efbf1b05e\Neo4jClient\GraphClient.cs:line 745
   at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()
---> (Inner Exception #0) System.AggregateException: One or more errors occurred. ---> System.Threading.Tasks.TaskCanceledException: A task was canceled.
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at Neo4jClient.GraphClient.<>c__DisplayClass3.<SendHttpRequestAsync>b__2(Task`1 requestTask) in c:\TeamCity\buildAgent\work\f1c4cf3efbf1b05e\Neo4jClient\GraphClient.cs:line 149
   at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()
---> (Inner Exception #0) System.Threading.Tasks.TaskCanceledException: A task was canceled.<---
<---

Answer 1

这是正在跟踪作为https://bitbucket.org/Readify/neo4jclient/issue/70/taskcancelledexception问题

诊断和最终的“官方”的决议将在那里公布。

Answer 2

我花了时间来确定这个问题并解决它。

[编辑]：不要使用Neo4jClient.GraphClient，使用Neo4jClient.BoltGraphClient - 从IGraphClient都获得 - 在BoltGraphClient不使用HttpClient的幕后，是方式更快，更占用大量内存。

var BoltGraphClient = new Neo4jClient.BoltGraphClient(url,username,password);

我的老答案+故事：

我把一吨的Cypher查询到List<Task>并通过query.ExecuteWithoutResultsAsync()执行它们。该Neo4j的服务器只能处理这么多的时间和将放在一个队列中的请求。

我已经证实，TaskCanceledException送出100秒后抛出，这是HttpClient的默认超时。

阅读文档后，我已经想通了如何将graphclient的初始化期间指定了无限的时间跨度。希望这将节省您的时间。

var httpClientWrapper = new Neo4jClient.HttpClientWrapper(
        username,
        password,
        new System.Net.Http.HttpClient() {
             Timeout = System.Threading.Timeout.InfiniteTimeSpan
        });

var graphClient = new Neo4jClient.GraphClient(new Uri(url), httpClientWrapper);