Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. This failure occured while attempting to connect to the Principle server.

Question

We are using SQL Server 2012.
Every now and then, when we execute the below stored procedure INSERT_INTO_MYTBL, we got the below error, and it returned @ID = 0.
"Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding. 
This failure occured while attempting to connect to the Principle server."
What causes this error, and how can we fix it ?
Thank you.
create procedure INSERT_INTO_MYTBL
@ID int output,
@Order varchar(50) = NULL,
@ACCOUNT varchar(20) = NULL
AS
DECLARE @Success int, @TryNr int, @ErrMsg varchar(500), @ErrNumber int, @expected_id int;
SET @Success = 0;
SET @TryNr = 1;
SET @ErrMsg = ''
WHILE @Success = 0 AND @TryNr <= 3 and @ErrMsg = ''
BEGIN;
BEGIN TRY;
BEGIN TRANSACTION;
retry:
BEGIN TRY;
SELECT @expected_id = ident_current('myTbl') + 1
SELECT @order = @account + '-' + CAST(@expected_id AS varchar(50))
insert into myTbl
([Order],ACCOUNT)
values
(@Order,@ACCOUNT)
END TRY
BEGIN CATCH;
SELECT @ErrNumber = ERROR_NUMBER()
IF @ErrNumber = 2627
BEGIN;
GOTO retry
END;
ELSE
BEGIN;
SET @ErrMsg = '1.' + ERROR_MESSAGE() + ' ' + @order
RAISERROR (@ErrMsg, 16, 1);
END;
END CATCH
select @ID = SCOPE_IDENTITY()
IF @id <> @expected_id
BEGIN
UPDATE myTbl
SET [Order] = @ACCOUNT + '-' + CAST(@ID AS varchar(50))
WHERE ID = @ID
END
SET @Success = 1
COMMIT TRANSACTION;
END TRY
BEGIN CATCH;
ROLLBACK TRANSACTION;
SELECT @ErrNumber = ERROR_NUMBER()
IF @ErrNumber = 1205
BEGIN;
SET @TryNr = @TryNr + 1;
IF @TryNr > 3
RAISERROR ('Giving up after 3 consecutive deadlocks for %s', 16, 1,@ACCOUNT);
END;
ELSE
BEGIN;
SET @ErrMsg = '2.' + ERROR_MESSAGE() + ' ' + @order
RAISERROR (@ErrMsg, 16, 1);
END;
END CATCH;
END;

Answer 1

When the problem occurs, the stored procedure returns @ID = 0, which I think means the query
When the problem occurs, the procedure does not return anything. SQL Server was told to stop executing. Furthermore, unless you issue the command SET XACT_ABORT ON, SQL Server will not roll back any open transaction. Which is one more reason you should not
permit command timeouts.
As for why this procedure sometimes take a long time, I would primarily suspect locking. When this occurs (but before the timeout elapses!), you could use my beta_lockinfo to see if there is any blocking going on. You find it here:
http://www.sommarskog.se/sqlutil/beta_lockinfo.html
Erland Sommarskog, SQL Server MVP, [email protected]