【发布时间】：2017-09-27 00:58:31
【问题描述】：
我在 CosmosDB 中创建了一个图表，其中包含两种顶点类型，一个演员顶点和一个电影顶点。唯一存在的边缘类型是“作用于”类型。您可以将图表想象为有很多演员和很多电影，并且任何给定的演员都可能演过任何数量的电影。
我正在尝试编写一个查询，该查询将发现并返回两个参与者之间的路径。例如，基努·里维斯与劳伦斯·菲什伯恩在《黑客帝国》中演出。劳伦斯·菲什伯恩与马龙·白兰度一起出演了电影《现代启示录》。因此，基努·里维斯和马龙·白兰度之间的路径是基努·里维斯 -> 黑客帝国 -> 劳伦斯·菲什伯恩 -> 现代启示录 -> 马龙白兰度。
这是我想出的查询。
g.V('keanureeves')
.repeat(both().simplePath())
.until(hasId('marlonbrando'))
.path()
.limit(1)
查询适用于小图。我可以查询和构建路径。但是，一旦我达到一定的图形大小，查询就会超时并且永远不会完成。
我在本地使用 CosmosDB 模拟器，而不是 Azure 上的真正 CosmosDB。很难说数据库中有多少文档，因为模拟器 UI 没有提供查询计数的方法。
我能否在不更改数据模型的情况下加快查询速度？如果我必须更改我的数据模型，什么会更好？我是图形数据库和 Gremlin 的新手。
编辑：它似乎发生在 1200 到 1300 个文档之间。在 1200 个文档下，返回结果。以下是文档类型的细分：
540 movie vertexes
112 actor vertexes
681 actedIn edges
编辑 #2：我正在使用 Microsoft.Azure.Graphs NuGet 包，看起来我正在调用的方法正在引发 OutOfMemory 异常。我的代码：
public async Task<IList<T>> ExecuteQueryAsync<T>(string gremlinQuery)
{
var query = _documentClient.CreateGremlinQuery(_graph, gremlinQuery);
var results = new List<T>();
while (query.HasMoreResults)
{
var feed = await query.ExecuteNextAsync<T>();
results.AddRange(feed.Select(x => x));
}
return results;
}
堆栈跟踪：
System.AggregateException: One or more errors occurred. ---> System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown.
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.GetTaskForResult(TResult result)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.SetResult(TResult result)
at Microsoft.Azure.Graphs.Runtime.Operators.ProjectOperator.<NextAsync>d__4.MoveNext()
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.Start[TStateMachine](TStateMachine& stateMachine)
at Microsoft.Azure.Graphs.Runtime.Operators.ProjectOperator.NextAsync()
at Microsoft.Azure.Graphs.Runtime.ScalarSubqueryFunction.<EvaluateAsync>d__3.MoveNext()
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
at System.Threading.Tasks.Task`1.get_Result()
at Microsoft.Azure.Graphs.Runtime.Operators.PathOperator.GetStepProjectionResult(FieldObject step, Int32& activeByFuncIndex)
at Microsoft.Azure.Graphs.Runtime.Operators.PathOperator.<NextAsync>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Graphs.Runtime.Operators.SimplePathOperator.<NextAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
at Microsoft.Azure.Graphs.Runtime.Operators.PathOperator.<NextAsync>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Graphs.Runtime.Operators.ProjectOperator.<NextAsync>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
at Microsoft.Azure.Graphs.Runtime.Operators.RepeatOperator.<NextAsync>d__18.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
at Microsoft.Azure.Graphs.Runtime.Operators.PathOperator.<NextAsync>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Graphs.Runtime.Operators.RangeOperator.<NextAsync>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Graphs.Runtime.Operators.ProjectOperator.<NextAsync>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Graphs.GraphTraversal.GraphTraversalIterator.<CurrentOperatorNextAsync>d__14.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Graphs.GraphTraversal.GraphTraversalIterator.<MoveNextAsync>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Graphs.GraphTraversal.<MoveNextAsync>d__17.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Graphs.GremlinDocumentQuery`1.<ExecuteNextAsync>d__15`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
at Octogami.SixDegreesOfNetflix.Application.Data.GremlinClient.<ExecuteQueryAsync>d__3`1.MoveNext() in C:\dev\SixDegreesOfNetflix\Application\Data\GremlinClient.cs:line 28
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
at Octogami.SixDegreesOfNetflix.Application.Data.ActorPathRepository.<GetPathBetweenActors>d__2.MoveNext() in C:\dev\SixDegreesOfNetflix\Application\Data\ActorPathRepository.cs:line 20
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
at Octogami.SixDegreesOfNetflix.Application.Feature.GetPathBetweenActorsCommandHandler.<Handle>d__3.MoveNext() in C:\dev\SixDegreesOfNetflix\Application\Feature\GetPathBetweenActors.cs:line 42
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
at Octogami.SixDegreesOfNetflix.Website.Controllers.ActorController.<DegreesOfSeparation>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeActionMethodAsync>d__27.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeNextActionFilterAsync>d__25.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ActionExecutedContext context)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeNextResourceFilter>d__22.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ResourceExecutedContext context)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeAsync>d__20.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Builder.RouterMiddleware.<Invoke>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.<Invoke>d__7.MoveNext()
---> (Inner Exception #0) System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown.
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.GetTaskForResult(TResult result)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.SetResult(TResult result)
at Microsoft.Azure.Graphs.Runtime.Operators.ProjectOperator.<NextAsync>d__4.MoveNext()
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.Start[TStateMachine](TStateMachine& stateMachine)
at Microsoft.Azure.Graphs.Runtime.Operators.ProjectOperator.NextAsync()
at Microsoft.Azure.Graphs.Runtime.ScalarSubqueryFunction.<EvaluateAsync>d__3.MoveNext()<---
【问题讨论】：
标签： c# gremlin azure-cosmosdb