Exception Occurs If Using Clr Sql

Hi all:
We are using a simple clr function in sql server, which splits input strings by a given delimiter. The code is in €œclr_sql.cs€?. And I wrote a simple stored proc in SQL Server 2005 which calls this function(storedproc.slq). Then I used a test application, which creates 80 threads to call this stored proc continuously. The client code is in client.cs. The TPS can reach to 2000+ in my test. Unfortunately, exception occurs sometimes (about 0.01%). Most of the exceptions are:
System.Data.SqlClient.SqlException: A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)
And there are a few others:
System.Data.SqlClient.SqlException: A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - The semaphore timeout period has expired.
System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding
I wrote a dummy T-Sql stored proc, which returns all the rows from an existing table (60 rows, the same dataset as the test above) directly. It€™s much faster than the clr one, and no exception occurs. And I also wrote a T-Sql stored proc which doing the same task as the clr one and is slower. It doesn€™t fail, neither.
To summarize my problem: exception occurs when using clr sql, but it vanish when using T-SQL. But we need CLR SQL because of the performance is better.
I€™m looking forward to hear from you. Thanks in advanceJ



/* clr sql.cs */

public class KspSplitString

{

[SqlFunction(FillRowMethodName = "FillRow")]

public static IEnumerable InitMethod(String input, char delimiter)

{

if (null == input)

return new string[] { };

return input.Split(new char[] { delimiter });



}

public static void FillRow(Object obj, out SqlString Term)

{

Term = (obj as string).Trim();

}

}


/* storedproc.sql */

ALTER proc [dbo].[spSplitString2] (@keywords nvarchar(max), @delimiter nchar)

as

set nocount on

select * from dbo.fnKspSplitString(@keywords, @delimiter)




/* client.cs */

SqlConnection conn;

public override void Setup()

{

conn = new SqlConnection(connectionString);

conn.Open();

}

public override void Cleanup()

{

conn.Close();

}

public override void Run()

{

try

{

using (SqlCommand command = new SqlCommand(storedproc, conn))

{

command.CommandType = CommandType.StoredProcedure;

command.CommandTimeout = sqlCommandTimeout;

SqlParameter sqlParameter = command.Parameters.Add("@Keywords", SqlDbType.NVarChar);

sqlParameter.Value = keywords;

sqlParameter = command.Parameters.Add("@Delimiter", SqlDbType.NChar);

sqlParameter.Value = delimiter;

using (SqlDataReader reader = command.ExecuteReader())

{

tblResult = new DataTable("RESULT");

tblResult.Load(reader);

}

}

}

catch (Exception ex)

{

Cleanup();

Setup();

}

}