[Mono-list] Issues with SqlClient and DataAdapter.Fill() under Linux

Tue Apr 22 10:39:52 EDT 2008

   Hello Veerapuram,

   Thank you for such a swift fix!! This will really help me out.

   Sorry for acting like a noob here, but can I get a diff from you  
with the vannila 1.9 source tree, or should I just grab the latest out  
of the 1.9 branch? Or if not, can you please let me know what files  
have changed, so that I can diff it myself?

   Regards,

   Mark.

Quoting Veerapuram Varadhan <vvaradhan at novell.com>:

> Hi Mark,
>
> Thanks for the detailed bug report and the test program.  Mark, myself
> and Nagappan had offline discussions on how to narrow down the issue and
> it stands fixed as of rev# 101411 and 101414 in mono-1-9 branch.
>
> His detailed bug report is here:
> https://bugzilla.novell.com/show_bug.cgi?id=381151
>
> Revert back in case of any regression or new bugs.
>
> Thanks,
>
> V. Varadhan
>
> On Wed, 2008-04-02 at 12:12 -0500, Mark Gimelfarb wrote:
>> Hello, all!
>>
>> I would like to get some feedback from the list before writing up a
>> bug on Bugzilla. I apologize for the lengthy post beforehand, but I
>> wanted to get as much detail in as I can to make it useful without
>> having to go back and forth on the list.
>>
>> We've converted an Asterisk.Net-based set of C# IVR code to run on
>> Linux. The code was  written using VS2k5 and .NET 2.0.
>>
>> Asterisk.Net has been modified to run as a daemon and to respond to
>> each incoming connection by spawning a thread, which will then access
>> MS SQL Server and query some data from it, processing it, and
>> returning a resulting AGI command back to Asterisk. All commands and
>> responses are text-based, and Asterisk.Net has no dependencies on any
>> libraries other than mono runtime and standard class libs.
>>
>> The current Linux set up is Mandriva 2007.0 with mono 1.2.3.1
>> accessing MS SQL Server 2000 SP4 running on a W2k3 box.
>>
>>
>> The process starts by issuing a SELECT query with a
>> DataAdapter.Fill(), which returns results just fine. However, a
>> subsequent call to a stored procedure which uses INSERT followed by
>> SELECT returns no rows (which causes System.IndexOutOfRangeException:
>> There is no row at position 0. exception while trying to iterate
>> through the DataRow collection coming back from Fill()'ed DataTable ).
>> We are using DataAdapter.Fill() from SqlClient to return the data back
>> to the calling code. There could be as much as a week between errors
>> or just one day or even one hour. The traffic does get heavy
>> sometimes, depending on the number of simultaneous calls, but load
>> doesn't always seem to be the issue, as we get the error below even in
>> relatively low-load conditions. After we received the error 10 or 20
>> times in a row, everything seems to come back to normal for a while.
>> This error doesn't occur on Windows under .NET 2.0 with exactly same
>> code.
>>
>>
>> Here's a snippet of the stack trace:
>>
>> Channel [Zap/1-1] [04/02 10:48:05] Exception caught:
>> System.IndexOutOfRangeException: There is no row at position 0.
>>    at System.Data.DataRowCollection.get_Item (Int32 index) [0x00040]
>> in   
>> /home/mandrake/rpm/BUILD/mono-1.2.3.1/mcs/class/System.Data/System.Data/DataRowCollection.cs:78
>>    at Asterisk.NET.FastAGI.Scripts.myRSCIVR.IVRNewCall (System.String
>> pcCaller, System.String pcCallee) [0x00066] in [.....]myfile.cs:372
>>
>> I omitted the non-relevant path to our code with [...]
>>
>> The bottom of the stack is our code trying to iterate through the
>> DataTable's DataRows coming back from Fill(). There should always be
>> data coming back, as INSERT succeeds every time, even if we get a
>> subsequent error. It's the SELECT that returns nothing back (Note,
>> it's not that it returns a row with NULLs, it returns no rows
>> whatsoever--an empty DataTable).
>>
>>
>> Before I submit the Bugzilla report I would like the list's opinion on
>> the following:
>>
>> 1) Has anyone had this problem before (is there another bug out there
>> already)? I searched the Bugzilla, but couldn't find exact same or
>> very similar issues. If someone has found a solution or a patch, that
>> would be great too :)
>>
>>
>> 2) Since the exception we get is not in Fill() itself, but rather
>> after that, I would like to see if I can somehow get the source for
>> the class lib and put some tracing code around fill  and use that
>> class lib instead of the stock one to get some tracing within the Fill
>> method of the DA, so that my Bugzilla report is most useful to the
>> ADO.NET team.
>>
>> 3) What all is needed to be submitted with the report to make this
>> issue easier to fix?
>>
>>
>> This issue is not easy to reproduce at will, so I'm hoping that this
>> is all helpful for starters.
>>
>>
>> Thank you all in advance for reading this monster of a post.
>>
>> Regards,
>>
>> Mark.
>>
>>
>> _______________________________________________
>> Mono-list maillist  -  Mono-list at lists.ximian.com
>> http://lists.ximian.com/mailman/listinfo/mono-list
>
>

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