Devart Forums

Hello,

An other unhandled exception in background Devart threads that drives a Windows Service to crash.

Application: Exis.eXray.AppServerService.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.ArgumentException
Stack:
at System.Collections.Generic.Dictionary`2[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].Insert(System.__Canon, System.__Canon, Boolean)
at Devart.Data.Linq.u.c(System.Data.Linq.Mapping.MetaType)
at Devart.Data.Linq.ae.b(Devart.Data.Linq.ad, Devart.Data.Linq.w ByRef)
at Devart.Data.Linq.i.a(Int32)
at Devart.Data.Linq.g.a(a)
at Devart.Data.Linq.g+a.b()

I guess the changes are also applied in the latest LinqConnect version?

Well, for now, it is only the matter of Direct Mode for me. Nevertheless, the same applies to all the extra features provided by dotConnect for Oracle. You effectively say that a product as dotConnect for Oracle which should work fine even after the support ends, renders unusable by an other product as LinqConnect of the same company! Don't you think that this is something that should be noted with big red letters on the relevant web page? Even for different projects, the configuration on a development machine would be a nightmare! Run the installations, get the files, don't mix them and reference them in projects not through the GAC but through the files on disk!! I think this is an investigation which should have been completed, way before the new product is released. For now, you just punish your best customers that made the mistake to make this transition...

Hello,

We have licenses for both LinqConnect and dotConnect for Oracle products. We started with dotConnect in order to use the LINQ facilities and we switched to LinqConnect when this was out. We are planning to continue updating the LinqConnect license indefinitely but we are not going to update the dotConnect license further more.

Now, the requirement is that we need to add the Direct connection feature of dotConnect product to our main LinqConnect product use and ONLY that. That is, we want to use the LINQ facilities of LinqConnect as is, but we need to be able to enable the Direct parameter in our connection.

Can this be done? What is the correct installation sequence that we must follow in order for this to work? What should we do when we need to update the LinqConnect product with every new version? There will be no need to update the dotConnect product as we will stop updating the relevant license. Can new versions of LinqConnect work flawlessly with an old, unupdated version of dotConnect?

We need to start this combination with versions LinqConnect 2.20.17 and dotConnect for Oracle 6.10.X. This is the last version of dotConnect that we can use.

We are using LinqConnect version 2.20.11.

The second exception happened again yesterday...

A second exception is encountered and caused the system to crash:

Application: Exis.eXray.AppServerService.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.AccessViolationException
Stack:
at OciDynamicType.nativeOCIHandleFree(System.Runtime.InteropServices.HandleRef, Int32)
at OciDynamicType.OCIHandleFree(System.Runtime.InteropServices.HandleRef, Int32)
at Devart.Data.Oracle.a.b(System.Object)
at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
at System.Threading.ThreadHelper.ThreadStart(System.Object)

It seems that this kind of errors are raised under stress.

The problem occured in OCI mode. Pooling is enabled with min connections set to 10 and max connections set to 100. System is RAC enabled with 2 nodes. Cannot send a test project as this is a rather complex configuration on which it happens as described at the other, related article. It's been a week now and it didn't occur and it didn't occur before that. It seems to be a one-timer. I will let you know if it gets persistent.

Hello,

At the system described in article http://www.devart.com/forums/viewtopic.php?t=19337 and using the latest LinqConnect version i got the following unhandled internal exception:

Application: Exis.eXray.AppServerService.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.InvalidOperationException
Stack:
at Devart.Common.DbConnectionInternal.d(System.Object)
at Devart.Common.DbConnectionPoolGroup.a(Devart.Common.DbConnectionPool)
at Devart.Common.DbConnectionPoolGroup.a(System.Object)
at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
at System.Threading._TimerCallback.PerformTimerCallback(System.Object)

It is the first time i get one of these. I will let you know about the frequency. In any case, i need this exception to be catched in your code because it crashes our entire CRM server.

I would also like to see this supported by LinqConnect. All my bulk inserts are performed through ExecuteQuery now and this is not good.

Hello,

Using the latest LinqConnect version, when i try to run the following LINQ:

var activationData = context.Query(
@"SELECT SupplyNo, ActivationDate, Processed AS Processed_Str, Success AS Success_Str, Message
FROM ORDER_ACTIVATION_DATES WHERE Processed = '0' OR Success = '0'");

var data = from objActData in activationData
join objSivLeft in context.ServiceIdentifierValues on objActData.SupplyNo equals
objSivLeft.ValueFrom into sivs
from objSiv in sivs.DefaultIfEmpty()
join objContractServiceLeft in context.ContractServices on objSiv.CsId equals
objContractServiceLeft.Id into cs
from objContractService in cs.DefaultIfEmpty()
join objContractProductLeft in context.ContractProducts on objContractService.CpId equals
objContractProductLeft.Id into cp
from objContractProduct in cp.DefaultIfEmpty()
join objActCaseLeft in context.Cases on new { CtId = 11L, RefScopeId = objContractProduct.Id }
equals new { objActCaseLeft.CtId, objActCaseLeft.RefScopeId } into actCases
from objActCase in actCases.DefaultIfEmpty()
select new
{
CurEvent = context.Events.Where(a => a.CaId == objActCase.Id).OrderByDescending(a => a.Id).FirstOrDefault(),
ActCase = objActCase,
Siv = objSiv,
Activation = objActData
};
var result = data.ToList();

I get a produced SQL that gives me an ORA-00933 error:

SELECT t6.EV_ID, t6.CA_ID, t6.ET_ID, t6.WR_ID, t6.EV_STATUS, t6.DATF, t6.DATT, t6.EV_MEMO, t6.EV_RESULT, t6.EV_ACT_STATUS, t6.CRUSER, t6.CRD, t6.CHUSER, t6.CHD, t6.CRAPPUSER, t6.CRAPPD, t6.CHAPPUSER, t6.CHAPPD, t6.EV_PRIORITY, t5.CA_ID AS CA_ID1, t5.CU_ID, t5.CT_ID, t5.CA_STATUS, t5.CA_PAR_ID, t5.CA_RESULT, t5.WDV_ID, t5.WR_ID_ENTRY, t5.WR_ID_EXIT, t5.CA_REF_SCOPE_ID, t5.CA_ACT_STATUS, t5.CRUSER AS CRUSER1, t5.CRD AS CRD1, t5.CHUSER AS CHUSER1, t5.CHD AS CHD1, t5.CRAPPUSER AS CRAPPUSER1, t5.CRAPPD AS CRAPPD1, t5.CHAPPUSER AS CHAPPUSER1, t5.CHAPPD AS CHAPPD1, t5.CA_PRIORITY, t5.DATF AS DATF1, t5.DATT AS DATT1, t2.SIV_ID, t2.SI_ID, t2.SU_ID, t2.CS_ID, t2.SIV_VALUE_FROM, t2.SIV_VALUE_TO, t2.SIV_ACT_DATE, t2.SIV_DEACT_DATE, t2.SIV_ACTION, t2.CU_ID AS CU_ID1, t2.CRUSER AS CRUSER2, t2.CRD AS CRD2, t2.CHUSER AS CHUSER2, t2.CHD AS CHD2, t2.SIV_ALLOW_EDIT, t1.SupplyNo AS "SupplyNo", t1.ActivationDate AS "ActivationDate", t1.Processed_Str AS "Processed_Str", t1.Success_Str AS "Success_Str", t1.Message AS "Message", t1.Processed AS "Processed", t1.Success AS "Success"
FROM (
SELECT SupplyNo, ActivationDate, Processed AS Processed_Str, Success AS Success_Str, Message
FROM ORDER_ACTIVATION_DATES WHERE Processed = '0' OR Success = '0'
) t1
LEFT OUTER JOIN SERV_IDENTIFIERS_VALUES t2 ON t1.SupplyNo = t2.SIV_VALUE_FROM
LEFT OUTER JOIN CONTRACT_SERVICES t3 ON t2.CS_ID = t3.CS_ID
LEFT OUTER JOIN CONTRACT_PRODUCTS t4 ON t3.CP_ID = t4.CP_ID
LEFT OUTER JOIN CASES t5 ON (:p0 = t5.CT_ID) AND (t4.CP_ID = t5.CA_REF_SCOPE_ID)
OUTER APPLY (
SELECT t7.EV_ID, t7.CA_ID, t7.ET_ID, t7.WR_ID, t7.EV_STATUS, t7.DATF, t7.DATT, t7.EV_MEMO, t7.EV_RESULT, t7.EV_ACT_STATUS, t7.CRUSER, t7.CRD, t7.CHUSER, t7.CHD, t7.CRAPPUSER, t7.CRAPPD, t7.CHAPPUSER, t7.CHAPPD, t7.EV_PRIORITY, ROW_NUMBER() OVER (ORDER BY t7.EV_ID DESC) AS "rnum"
FROM (
SELECT t8.EV_ID, t8.CA_ID, t8.ET_ID, t8.WR_ID, t8.EV_STATUS, t8.DATF, t8.DATT, t8.EV_MEMO, t8.EV_RESULT, t8.EV_ACT_STATUS, t8.CRUSER, t8.CRD, t8.CHUSER, t8.CHD, t8.CRAPPUSER, t8.CRAPPD, t8.CHAPPUSER, t8.CHAPPD, t8.EV_PRIORITY
FROM EVENTS t8
WHERE t8.CA_ID = t5.CA_ID
ORDER BY t8.EV_ID DESC
) t7
) t6
WHERE t6."rnum" <= 1

SQL command brakes just before the OUTER APPLY part. I tested the query on 10.2 & 11.2 systems.

It's been a month. Anything new on that?

Mystcreater,

From your comments, it is apparent that you have weak knowledge of the way a data access layer should work. If you find useful to open a lot of (physical?) connections and DataContexts to a database and you find this thing great even for a WinForms application, i think you are not yet in a position to evaluate or even appreciate an ORM solution. Many vendors have their reason(sales!) to present their products as "plug n play" solutions that fit into any need without proper basic knowledge. Take my word for it, this is hardly the case, especially for an ORM solution! Proper choice of an ORM solution demands professional knowledge of software architecture layers, to which, one usually gets, when he has enough experience to actually start to build such a solution!

My advice for you is to start design things a little bit, understand about data access and business layers and then try to incorporate an ORM solution to fit your needs. If you have small projects that span a few thousand lines of code, an ORM solution that you are not really comfortable with, will probably increase project completion time more that you can handle.

That said, i use LinqConnect in a CRM Application Server solution spanning 23 projects, 10 WCF Services that get loaded in different application domains in the same process, serving hundreds of concurrent DB requests from Win, Web, Silverlight and Mobile Clients through multiple web service threads. And yes, everything works rather smooth. But this is more because i really know where an ORM solution fits and less because LinqConnect offers everything out of the box! For example, in such an implementation where hundreds of concurrent Database requests are needed, if i kept a large number of open connections without using the facilities of connection pooling and creating and disposing datacontexts when needed, i would reach connection exhaustion really fast and the exceptions raised would be continuous! And LinqConnect or any other ORM solution would have nothing to do with it!

I really hope you get my point...

That is true. Using the latest version, a CLOB column can be generated as described. Thanks.

To continue, i have some observations:

1). What is the point of MaxLength facet for numbers? It seems that only the precision and scale are checked for proper column data type generation.

2). Is seems to me that there is not a way to generate a CLOB column. I have a string property which i need it to map to a CLOB. If i set MaxLength = -1, a VARCHAR2(4000) is generated. If i set the MaxLength to a large Int32 like 9999999, an error (i guess) is raised. I only get a message "convertType" when switching to the "Choose Schemas" form of the relevant wizard.

Of course, the aforementioned issues should be properly handled for all DB Types.