Testing linked server conccetion inside trigger or

Question

I wrote a trigger that updates local table and similar table on linked server.

CREATE TRIGGER myTtableUpdate ON myTable
AFTER UPDATE AS
IF (COLUMNS_UPDATED() > 0)
BEGIN
DECLARE @retval int;
BEGIN TRY
EXEC @retval = sys.sp_testlinkedserver N'my_linked_server';
END TRY
BEGIN CATCH
SET @retval = sign(@@error);
END CATCH;

IF (@retval = 0)
BEGIN
UPDATE remoteTable SET remoteTable.datafield = i.datafield
FROM my_linked_server.remote_database.dbo.myTable remoteTable
INNER JOIN inserted i ON (remoteTable.id = i.id)
END
END -- end of trigger

Unfortunately when connection is down I get error message
'Msg 3616, Level 16, State 1, Line 2'
'Transaction doomed in trigger. Batch has been aborted'
and locally made update is rolled back.

Is there a way to maintain this error and keep local updates?
Note that I'm using SQL Server 2005 Express Edition on both PCs running Windows XP Pro.

edit1: SQL server is Express Edition
edit2: Both PCs run Windows XP Pro so these aren't servers

Answer 1

don't write to the remote server in the trigger.

• create a local table to store rows that need to be pushed to the remote server
• insert into this new local table in the trigger
• create a job that runs every N minutes to insert from this local table into remote server.

this job can run a procedure that can test for the connection, and when it is back up, it will handle all rows in the new local table. It can process the rows in the local table this way:

declare @OutputTable table (RowID int not null)

insert into my_linked_server.remote_database.dbo.myTable remoteTable(...columns...)
    OUTPUT INSERTED.RowID
    INTO @OutputTable
    SELECT ...columns...
        from NewLocalTable

delete NewLocalTable
   from NewLocalTable           n
       inner join @OutputTable  o ON n.RowID=o.RowID

EDIT based OP comment
after inserting into this new local table start the job from the trigger (sp_start_job), it will run in its own scope. If you can't use sql server jobs, use xp_cmdshell to execute the stored procedure (lookup SQLCMD or ISQL or OSQL, I'm not sure what you have). still schedule the job every N minutes, so it will eventually run when the connection comes up.

Answer 2

Is at least one of the servers Workgroup edition or higher? You can use Service Broker to ship your records instead of linked servers, but it will not work between to Express editions due to licensing restrictions. Is a solution relying exclusively on SQL, offers reliability in case of incidents (one of the servers is unavailable) and your updates will propagate in real time (as soon as they are committed). My site has many examples on how to do this, you can start with this article here on how to achieve high message throughput.