Can I create MSDTC Transaction in PowerShell? - sql-server

I am using Powershell 4 to do some deployment tasks including running a number of sql files into a database server.
http://technet.microsoft.com/en-us/library/dn464259.aspx
I have found the above cmdlets for MSDTC and I can see one for creating a transaction, rollback and commit. However, I cant find them and I assume its because we are not running Windows 8 and/or Server 2012 R2.
Is there a way that I can create a transaction scope using MSDTC so I can execute all of my scripts knowing that if any of them fail, that they will all roll back?
We are running Windows 7 & Server 2008 R2.

I don't think that you should try using PowerShell with MSDTC directly in the way that you are thinking. Instead I would just use plain old SQL TRANSACTION statements: BEGIN COMMIT and ROLLBACK...
I think what you really are looking for is the SQL statement BEGIN DISTRIBUTED TRANSACTION
See: MSDN: BEGIN DISTRIBUTED TRANSACTION
This will use MSDTC to execute several scripts over the same session and be able to commit, or rollback the transaction.

If Network DTC Access is enabled, you can use a simple try/catch and invoke .NET's TransactionScope object.
try {
$scope = New-Object -TypeName System.Transactions.TransactionScope
# do stuff
} catch {
$_.exception.message
} finally {
$scope.Dispose()
}
Calling Dispose() on the TransactionScope will either commit or rollback the changes.

Related

Is there any way to rollback transactions in SSIS for SQL Server 2012?

Cannot successfully execute an SSIS package with BEGIN TRAN functionality.
I'm at a loss with an SSIS package I inherited. It contains:
1 Script Task
3 Execute SQL tasks
5 Data flow tasks (each contains a number of merges, lookups, data inserts and other transformations)
1 file system task of the package.
All of these are encapsulated in a Foreach loop container. I've been tasked with modifying the package so that if any of the steps within the control/data flow fails, the entire thing is rolled back. Now I've tried two different approaches to accomplish this:
I. Using Distributed Transactions.
I ensured that:
MSDTC was running on target server and executing client (screenshot enclosed)
msdtc.exe was added as an exception to server and client firewall
Inbound and outbound rules were set for both server and client to allow DTC connections.
ForeachLoop Container TrasanctionLevel: Required
All other tasks TransactionLevel: Supported
My OLEDB Connection has RetainSameConnection set to TRUE and I'm using SQL Server Authentication with Save Password checked
When I execute the package, it fails right after the script task (first step).
After spending an entire week trying to figure out a workaround, I decided to try SQL Tasks to try to accomplish my goal using 3 Execute SQL Tasks:
BEGIN TRAN before the ForeachLoop Container
COMMIT TRAN after the ForeachLoop Container with a Success Constraint
ROLLBACK TRAN after the ForeachLoop Container with a Failure constraint
In this case, the ForeachLoop container and all other tasks have TransactionLevel property set to Supported. Now here, the problem is that the package executes up to the fourth data flow task and hangs there forever. After logging into SQL Server and verifying the running sessions, I noticed sys.sp_describe_first_result_set;1 as a headblocker session.
Doing some research, I found it could be related to a few TRUNCATE statements in some of my Data flow tasks which could cause a schema lock. I went ahead and changed the ValidateExternalMetaData property to False for all tasks within my data flow and changed my truncate statements to DELETE statements instead. Re-ran package and still hangs in the same spot with the same headblocker. As an alternative, I tried creating a second OLEDB connection to the same database, assigned that new OLEDB Connection to my BEGIN, ROLLBACK and COMMIT SQL tasks with RetainSameConnectionProperty set to TRUE and changed the RetainSameConnectionProperty to FALSE (and tried it with TRUE as well) in the original OLEDB connection (the one used by the data flow tasks). This worked in the sense that the package appeared to execute (It ran and Commit Tran executed fine) and then I ran it again with a forced error to cause it to fail and the Rollback TRAN task executed successfully, however, when I queried the affected tables, the transaction hadn't rolled back, all new records were inserted and old ones were updated (the begin tran was clearly started in a different connection and hence didn't affect the package's workflow). I'm not sure what else to try at this point. Any help would be truly appreciated, I’m about to go nuts with this!
P.S. additionally, all objects have "DelayValidation" set to true on everything and SQL Server version is 2012.

SQL Server: How to make a transaction commit fail?

To test error handling in an application, I'm looking for a way to let a transaction commit result in an error.
The application is written in C and uses ODBC to talk to a SQL Server 2017 data source. The application starts a database transaction and executes an arbitrary SQL (which I can change for the sake of the test). Then, it commits the transaction (using ODBCs SQLEndTran()). I want to build a test that verifies the error handling of the commit.
Is there an easy way and reliable way to let the commit fail, e.g by executing some specific SQL script before the commit, or by changing the database or the data source settings?
EDIT / clarification: What I need to fail is the transaction commit itself (specifically the SQLEndTran() complete call with an error). SQL before that shall complete successfully.
If you are able to time it correctly in a testing framework you can do few things:
1. Kill session from a separate connection in a testing framework.
2. Change firewall configuration to emulate network error.
3. Switch database to single user mode or stop SQL Service.
Easiest way is to force a divide by zero.
declare #SomeVal int = 0
set #SomeVal = 2 / #SomeVal
--EDIT--
Since I guess you want the commit to fail you could simply add a rollback right before the commit. Then the exception would be thrown on the commit statement.

Database Table lock

I'm using SQL 2000 for my application. My application is using N tables.
My application has a wrapper for SQL server called Database server. It is running as a 24/7 windows service.
If I have checked the integrity check option in the SQL maintenance plan, when this task is running one time after that one of my tables has been locked and it has been never unlocked.
So my history of the database transaction has been lost.
Please provide your suggestion how to solve this problem.
What if you have a client-side command timeout? And the locks are your own locks as a result of the DBCC?
Your code will timeout waiting for the DBCC to finish, but any locks it's already issued are not rolled back.
A command timeout tells SQL Server to simply stop processing. To release locks you need to either ROLLACK on the connection or close the connection.
Options:
Use SET XACT_ABORT in the SQL: Do I really need to use “SET XACT_ABORT ON”? (SO)
On client error, try and rollback yourself (Literally IF ##TRANCOUNT > 0 ROLLBACK TRAN)

Extreme wait-time when taking a SQL Server database offline

I'm trying to perform some offline maintenance (dev database restore from live backup) on my dev database, but the 'Take Offline' command via SQL Server Management Studio is performing extremely slowly - on the order of 30 minutes plus now. I am just about at my wits end and I can't seem to find any references online as to what might be causing the speed problem, or how to fix it.
Some sites have suggested that open connections to the database cause this slowdown, but the only application that uses this database is my dev machine's IIS instance, and the service is stopped - there are no more open connections.
What could be causing this slowdown, and what can I do to speed it up?
After some additional searching (new search terms inspired by gbn's answer and u07ch's comment on KMike's answer) I found this, which completed successfully in 2 seconds:
ALTER DATABASE <dbname> SET OFFLINE WITH ROLLBACK IMMEDIATE
(Update)
When this still fails with the following error, you can fix it as inspired by this blog post:
ALTER DATABASE failed because a lock could not be placed on database 'dbname' Try again later.
you can run the following command to find out who is keeping a lock on your database:
EXEC sp_who2
And use whatever SPID you find in the following command:
KILL <SPID>
Then run the ALTER DATABASE command again. It should now work.
There is most likely a connection to the DB from somewhere (a rare example: asynchronous statistic update)
To find connections, use sys.sysprocesses
USE master
SELECT * FROM sys.sysprocesses WHERE dbid = DB_ID('MyDB')
To force disconnections, use ROLLBACK IMMEDIATE
USE master
ALTER DATABASE MyDB SET SINGLE_USER WITH ROLLBACK IMMEDIATE
Do you have any open SQL Server Management Studio windows that are connected to this DB?
Put it in single user mode, and then try again.
In my case, after waiting so much for it to finish I had no patience and simply closed management studio. Before exiting, it showed the success message, db is offline. The files were available to rename.
execute the stored procedure
sp_who2
This will allow you to see if there is any blocking locks.. kill their should fix it.
In SSMS: right-click on SQL server icon, Activity Monitor. Open Processes. Find the processed connected. Right-click on the process, Kill.
In my case I had looked at some tables in the DB prior to executing this action. My user account was holding an active connection to this DB in SSMS. Once I disconnected from the server in SSMS (leaving the 'Take database offline' dialog box open) the operation succeeded.
anytime you run into this type of thing you should always think of your transaction log. The alter db statment with rollback immediate indicates this to be the case. Check this out: http://msdn.microsoft.com/en-us/library/ms189085.aspx
Bone up on checkpoints, etc. You need to decide if the transactions in your log are worth saving or not and then pick the mode to run your db in accordingly. There's really no reason for you to have to wait but also no reason for you to lose data either - you can have both.
Closing the instance of SSMS (SQL Service Manager) from which the request was made solved the problem for me.....
To get around this I stopped the website that was connected to the db in IIS and immediately the 'frozen' 'take db offline' panel became unfrozen.
Also, close any query windows you may have open that are connected to the database in question ;)
I tried all the suggestions below and nothing worked.
EXEC sp_who
Kill < SPID >
ALTER DATABASE SET SINGLE_USER WITH Rollback Immediate
ALTER DATABASE SET OFFLINE WITH ROLLBACK IMMEDIATE
Result: Both the above commands were also stuck.
4 . Right-click the database -> Properties -> Options
Set Database Read-Only to True
Click 'Yes' at the dialog warning SQL Server will close all connections to the database.
Result: The window was stuck on executing.
As a last resort, I restarted the SQL server service from configuration manager and then ran ALTER DATABASE SET OFFLINE WITH ROLLBACK IMMEDIATE. It worked like a charm
In SSMS, set the database to read-only then back. The connections will be closed, which frees up the locks.
In my case there was a website that had open connections to the database. This method was easy enough:
Right-click the database -> Properties -> Options
Set Database Read-Only to True
Click 'Yes' at the dialog warning SQL Server will close all connections to the database.
Re-open Options and turn read-only back off
Now try renaming the database or taking it offline.
For me, I just had to go into the Job Activity Monitor and stop two things that were processing. Then it went offline immediately. In my case though I knew what those 2 processes were and that it was ok to stop them.
In my case, the database was related to an old Sharepoint install. Stopping and disabling related services in the server manager "unhung" the take offline action, which had been running for 40 minutes, and it completed immediately.
You may wish to check if any services are currently utilizing the database.
Next time, from the Take Offline dialog, remember to check the 'Drop All Active Connections' checkbox. I was also on SQL_EXPRESS on local machine with no connections, but this slowdown happened for me unless I checked that checkbox.
SSMS, especially if running it from your own desktop remotely and not directly within the database server, can be a reason for the long delays in detaching a database. For some reason SSMS may not be able to disconnect any existing "connections" to the database.
We found the process was almost instant when we did it directly from the database server itself. And in fact it killed the attempt from my own desktop SSMS session, and it "took over" and detached the database.
Nothing else suggested here worked.
Thanks
In my case i stopped Tomcat server . then immediately the DB went offline .

Scheduled run of stored procedure on SQL server

Is it possible to set up somehow Microsoft SQL Server to run a stored procedure on regular basis?
Yes, in MS SQL Server, you can create scheduled jobs. In SQL Management Studio, navigate to the server, then expand the SQL Server Agent item, and finally the Jobs folder to view, edit, add scheduled jobs.
If MS SQL Server Express Edition is being used then SQL Server Agent is not available. I found the following worked for all editions:
USE Master
GO
IF EXISTS( SELECT *
FROM sys.objects
WHERE object_id = OBJECT_ID(N'[dbo].[MyBackgroundTask]')
AND type in (N'P', N'PC'))
DROP PROCEDURE [dbo].[MyBackgroundTask]
GO
CREATE PROCEDURE MyBackgroundTask
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
-- The interval between cleanup attempts
declare #timeToRun nvarchar(50)
set #timeToRun = '03:33:33'
while 1 = 1
begin
waitfor time #timeToRun
begin
execute [MyDatabaseName].[dbo].[MyDatabaseStoredProcedure];
end
end
END
GO
-- Run the procedure when the master database starts.
sp_procoption #ProcName = 'MyBackgroundTask',
#OptionName = 'startup',
#OptionValue = 'on'
GO
Some notes:
It is worth writing an audit entry somewhere so that you can see that the query actually ran.
The server needs rebooting once to ensure that the script runs the first time.
A related question is: How to run a stored procedure every day in SQL Server Express Edition?
Yes, if you use the SQL Server Agent.
Open your Enterprise Manager, and go to the Management folder under the SQL Server instance you are interested in. There you will see the SQL Server Agent, and underneath that you will see a Jobs section.
Here you can create a new job and you will see a list of steps you will need to create. When you create a new step, you can specify the step to actually run a stored procedure (type TSQL Script). Choose the database, and then for the command section put in something like:
exec MyStoredProcedure
That's the overview, post back here if you need any further advice.
[I actually thought I might get in first on this one, boy was I wrong :)]
Probably not the answer you are looking for, but I find it more useful to simply use Windows Server Task Scheduler
You can use directly the command sqlcmd.exe -S "." -d YourDataBase -Q "exec SP_YourJob"
Or even create a .bat file. So you can even 2x click on the task on demand.
This has also been approached in this HERE
I'll add one thing: where I'm at we used to have a bunch of batch jobs that ran every night. However, we're moving away from that to using a client application scheduled in windows scheduled tasks that kicks off each job. There are (at least) three reasons for this:
We have some console programs that need to run every night as well. This way all scheduled tasks can be in one place. Of course, this creates a single point of failure, but if the console jobs don't run we're gonna lose a day's work the next day anyway.
The program that kicks off the jobs captures print messages and errors from the server and writes them to a common application log for all our batch processes. It makes logging from withing the sql jobs much simpler.
If we ever need to upgrade the server (and we are hoping to do this soon) we don't need to worry about moving the jobs over. Just re-point the application once.
It's a real short VB.Net app: I can post code if any one is interested.
You could use SQL Server Service Broker to create custom made mechanism.
Idea (simplified):
Write a stored procedure/trigger that begins a conversation (BEGIN DIALOG) as loopback (FROM my_service TO my_service) - get conversation handler
DECLARE #dialog UNIQUEIDENTIFIER;
BEGIN DIALOG CONVERSATION #dialog
FROM SERVICE [name]
TO SERVICE 'name'
...;
Start the conversation timer
DECLARE #time INT;
BEGIN CONVERSATION TIMER (#dialog) TIMEOUT = #time;
After specified number of seconds a message will be sent to a service. It will be enqueued with associated queue.
CREATE QUEUE queue_name WITH STATUS = ON, RETENTION = OFF
, ACTIVATION (STATUS = ON, PROCEDURE_NAME = <procedure_name>
, MAX_QUEUE_READERS = 20, EXECUTE AS N'dbo')
, POISON_MESSAGE_HANDLING (STATUS = ON)
Procedure will execute specific code and reanable timer to fire again.
You can find fully-baked solution(T-SQL) written by Michał Gołoś called Task Scheduler
Key points from blog:
Pros:
Supported on each version (from Express to Enterprise). SQL Server Agent Job is not available for SQL Server Express
Scoped to database level. You could easiliy move database with associated tasks (especially when you have to move around 100 jobs from one enviromnent to another)
Lower privileges needed to see/manipulate tasks(database level)
Proposed distinction:
SQL Server Agent (maintenance):
backups
index/statistics rebuilds
replication
Task Scheduler (business processes):
removing old data
preaggregations/cyclic recalculations
denormalization
How to set it up:
get source code from section: "Do pobrania" - To download
(enabling broker/setting up schema tsks/configuration table + triggers + stored procedure)/setting up broker things)
set up configuration table [tsks].[tsksx_task_scheduler] to add new tasks (columns names are self-descriptive, sample task included)
Warning: Blog is written in Polish but associated source code is in English and it is easy to follow.
Warning 2: Before you use it, please make sure you have tested it on non-production environment.
Using Management Studio - you may create a Job (unter SQL Server Agent)
One Job may include several Steps
from T-SQL scripts up to SSIS Packages
Jeb was faster ;)
You should look at a job scheduled using the SQL Server Agent.

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