Impact of Rebooting Server on In-Memory Data

[mce]

Hi,

When a Window server, which hosts TM1 servers, is rebooted and if there was in memory data in TM1 cubes that is not saved to disk yet, what happens about the in memory data? Does Windows properly stop the services first before rebooting which forces TM1 to save in memory data to disk? In this case, if saving in memory data takes long time, does Windows wait for it or does it timeout after some time and just kills the process causing in memory data to be lost?

Thanks for any responses.

Regards

[Sebastian Paulussen]

Hi mce,

first of all you should say which Windows server is in Question since there are many different Versions out there and even the Desktop Systems can be used as Servers.

A Reboot of a Server should never happen unintentionally so I think you should better ask if your Operating Manual is up to date and states in the Section Reboot procedure that you have first shut down the TM1 Process or better save the Data from the application itself. If you use a script simply add a line which shut downs the service first and waits for the right exit code before proceeding to the reboot.

For regular Maintenance Rebooting you surely do have a SaveDataAll Process with an Chores defined.

Regards

Sebastian

[mce]

The question is for Windows Server 2003 and Windows Server 2008.
This is not a question of procedure, but to understand what happens if someone does it without properly stopping the TM1 services.

[Sebastian Paulussen]

There is a registry key for a service Kill timeout. The Number is in ms.

http://support.microsoft.com/kb/Q146092
http://support.microsoft.com/kb/Q839262

[HKEY_LOCAL_MACHINE \System \CurrentControlSet \Control]
WaitToKillServiceTimeout = "20000"

So if the Service takes to much time to stop it should be killed and there is a possibility of data loss even if your cube logging is active. If you do have an environment where there could be an reboot without proper routine i would emphasize testing service stopping time, changing the key to that time frame + x.

[Steve Vincent]

Actually it depends on your TM1 server setup. Data (numbers stored in a cube) isn't lost if you are logging every change as it's stored in tm1s.log in the data directory as well as in RAM. It is then flushed to a date stamped version of that log when save data is initiated, as well as to the cub file. If an instance of TM1 is stopped without that happening, the default action taken by TM1 as the service is restarted is to look in the tm1s.log and "re-import" any data that maybe left in there. This means that no "data" is lost. Any data changes you don't log will be lost if the server was unable to complete a save data, as the only place it resides before then is in RAM.

[mce]

Thanks for responses.