Massive exceptions

listonic · Post by **listonic** » Fri 23 Dec 2011 09:42

Today my application went down. After checking logs i realized, there was an exception in your library during every database access.

I cannot give you more information besides the stack trace. This is second strange exception which i am receiving using your library and i cannot do anything about it bacuase the core cause of it cannot be determined. Is it posible that you share the symbols for your libraries so i could at least give you more accurate information about the exception when it occurs ? Such strange exception make me start thinking about finding another database solution becuase your library started to be unreliable.

System.NullReferenceException: Object reference not set to an instance of an object. at System.Collections.Generic.LinkedList`1.InternalInsertNodeBefore(LinkedListNode`1 node, LinkedListNode`1 newNode) at Devart.Data.Linq.CompiledQueryCache.a(b A_0, CompiledQuery A_1) at Devart.Data.Linq.Provider.DataProvider.BuildQuery(Expression query) at Devart.Data.Linq.Provider.DataProvider.Devart.Data.Linq.Provider.IProvider.Compile(Expression query) at Devart.Data.Linq.DataQuery`1.i() at System.Linq.Enumerable.d__81`1.MoveNext() at System.Linq.Enumerable.d__4d`1.MoveNext() at System.Linq.Enumerable.d__3a`1.MoveNext() at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source) at Listonic.Gazetki.Data.MarketSetItemDs.GetByListFiltered(Int64 listId, Int32 first, Int32 count) in at ASP.secure_list_aspx.__RenderContent2(HtmlTextWriter __w, Control parameterContainer) at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at ASP.defaultmaster_master.__Rendercontainer(HtmlTextWriter __w, Control parameterContainer) at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) at System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) at ASP.defaultmaster_master.__Render__control1(HtmlTextWriter __w, Control parameterContainer) at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.Page.Render(HtmlTextWriter writer) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) Object reference not set to an instance of an object.

StanislavK · Post by **StanislavK** » Mon 26 Dec 2011 15:25

Please specify the version of LinqConnect you are using.

According to the stack trace, the problem occurs when adding a query to the compiled query cache. To find the query that causes the issue, you can, e.g., enable logging of executed SQL commands ( http://www.devart.com/linqconnect/docs/Monitoring.html ) and check the latest one. Please describe this query.

As a workaround, you can also disable query caching. To do so, you can, e.g., comment out the following line in the generated code:

Code: Select all

public static Devart.Data.Linq.CompiledQueryCache compiledQueryCache = 
  Devart.Data.Linq.CompiledQueryCache.RegisterDataContext(typeof([YourDataContext]));

listonic · Post by **listonic** » Fri 30 Dec 2011 11:28

I am using version 3.0.16. I do not know what the query is becuase this issue occured once so far on production server so i am not able to debug it.

StanislavK · Post by **StanislavK** » Thu 05 Jan 2012 17:29

If the problem occurs again, and you are able to determine the query that caused it, we would be grateful if you specify this query.

As for removing the obfuscation of the LinqConnect libraries, we plan to release an edition including the source code, though cannot provide any timeframe for it at the moment.