Introduction
A few weeks ago I assisted with a General Ledger year end for a GP user with a very large number of journals and consequently a very large SQL database.
Usually a year end is a fairly straight forward routine, however as this user has such a large database, along with additional SQL bits and pieces for disaster recovery and bespoke reporting, it required a little more thought to ensure things went as smoothly as possible.
In this post I thought I’d share the steps I took to hopefully assist anyone else facing a similar situation in the future.
Here goes…..
1) Do the basics first.
By basics I mean following Microsoft’s general Year End prerequisites which can be found here.
I find the most important steps are ensuring you have a good backup and also ensuring the general ledger codes have the correct posting type as this can be a pain to correct post year end.
2) Ensure you have enough disk space for the SQL Data and SQL Log files.
This usually isn’t a consideration when running the Year End however given the size of the data its something that needs planning when dealing with GL tables in the 100’s of GBs.
Microsoft’s official guidance on disk space is included in the Year End documentation that I’ve linked to above however I’ve copied the section on disk space below:
During the year-end closing routine, all the records that will be moved are put in a temporary table before they are moved to the GL30000 table. You must have free disk space that is equal to the size of the GL20000 table to perform the routine.
To find the current size of the GL20000 you can use the sp_spaceused system stored procedure i.e.
However I’d also add that when dealing with large data volumes you also need to plan for extraordinary SQL transaction log growth as well.
For example the SQL transaction log grew to 240GB when I did this particular year end. This is because various statements including the INSERT statements into GL30000 are completed in one SQL transaction. Therefore no matter what the SQL recovery model is of your database, the log file is going to grow while the process completes. This is standard behaviour so SQL can roll the whole transaction back should any issue occur.
3) Remove any Database Mirroring or Availability Groups.
In my scenario the user has database mirroring for disaster recovery. I could have left this on however this would result in a lot of transaction log being sent over the wire while the Year End ran potentially doubling the length time it takes. I always see the amount of time something takes, as the size of the window of opportunity for something to go wrong. The quicker I could get the Year End process to go, the less chance I had of something going wrong. On the down side it does mean I had additional configuration to complete post year end, but I was fine with this.
4) Remove any custom indexes
If you have any additional custom indexes on GL20000 and GL30000 its best to remove them. Again its not a problem if you don’t remove them, however it can slow things down and also increase the amount of transaction log that SQL will produce. This is because if you are DELETEing and INSERTing data into tables the indexes also have to be updated. Therefore the less indexes you have the better. This requires additional space and also additional log to record the operations.
**Don’t remove any of the standard indexes though.
5) Stop the SQL Agent.
Maintenance tasks like reindex routines sometimes use the SQL agent to run. As I suspected the Year End will run for a very long time, I stopped the SQL agent to prevent this from happening. Its always best to check that critical operations won’t be affected by this though. If so just disable any SQL jobs that run maintenance on the Dynamics databases.
6) Temporarily revoke permissions for any Reporting Logins.
Ideally I’d like to set the database to single user mode while the Year End ran however as I wanted to monitor the process I didn’t want to restrict this too much. I therefore disable logins that I knew were used for reporting in case anyone sets off a large report in the middle of the year end.
7) Ensure SQL log growth on the database is set sensibly.
As I mentioned above the SQL transaction log is going to grow during this operation regardless of the recovery model. Therefore go to the properties of the SQL database and ensure the growth is set correctly, and its set in MB’s rather than a percent. I set it to grow 10GB increments for this particular year end process.
8) Use SQL monitoring scripts
I like to nosy under the hood when running most things but I especially want a sneak peak on the General Ledger Year End. My tool of choice for this is Adam Machanic’s awesome free monitoring tool sp_whoisative. This is a free script you can use to monitor activity in SQL. Using this I can pretty much see at what point the Year End was up to. i.e. INSERTing the data to GL30000 etc.
**If you didn’t know about this free script, and this is all you take away from this blog I’d be happy :). Its a really cool free tool you can use when troubleshooting all sorts of things in SQL i.e. blocking etc.
I also want to monitor my database and log growth as the process is running. If I monitor this I can predict when the log will run out of space and need to grow. I then check the disk space to ensure the growth will happen smoothly. To do this I use this script
SELECT DB_NAME() AS DbName,
name AS FileName,
size/128.0 AS CurrentSizeMB,
size/128.0 - CAST(FILEPROPERTY(name, 'SpaceUsed') AS INT)/128.0 AS FreeSpaceMB
FROM sys.database_files; 9) Be patient 🙂
One of the most important things is to be patient as this routine can last hours on a large data set. Its also important to never cancel the operation by manually closing GP down even if it says “Not Responding”. If it doubt you can run the sp_whoisactive stored procedure and check what’s happening on the server.
10) Once complete
After a huge sigh of relief I performed an additional backup and then started recreating the indexes, setting up the mirroring and restarting the SQL agent. I also shrank the SQL transaction log back down to a reasonable size.
Conclusion
I hope you find the information in this post useful. Although you may not need to follow all the points I outlined, I think the most important are disk space for the SQL transaction log, monitoring and lots of patience 🙂
Thanks for reading!
The Dynamics Explorer 