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[WD17] - Generated App hands randomly
Iniciado por guest, 21,mar. 2016 07:39 - 5 respuestas
Publicado el 21,marzo 2016 - 07:39
Hello,

The subject says it all.

We have developed an app that is using HF SQL Classic as database back end.

It is being used/run at times from multiple PCs on network.
Here all the other PCs are running the same software EXE from the main server where the folder of this software is shared.

The software hangs randomly at times without any reason. When it hangs on one PC it happens to all other PC where it is running.

Again if we End Task the software and restart it (some times on all PC in network that are running this software), It starts working properly. Again after some time it randomly hangs.

There are no error messages, nothing to track down the problem. What must be the problem?

While compiling the option - Multi Instance is set (if this info will help)

Please help solve this.

TIA

Yogi Yang
Publicado el 21,marzo 2016 - 09:06
Hello,

Sharing a database (as a File) on Windows servers 2008 or Windows 7 or higher can cause very strange behaivior and is not recommended !! This can cause data corruption. Best is to use Client/server option !

This is due to the SMB3/2 implementation on Server 2008/2012 Windows 7/8/10.

See: https://social.technet.microsoft.com/Forums/windowsserver/en-US/7336d31b-6c24-468a-9c47-750244ae3a8c/moved-to-server-2012-getting-access-database-corruption…
or http://kokhonyin.blogspot.be/2012/05/smb-and-opportunistic-locking-revisit.html
for more information about the subject.

There is more info and details on the Internet when you Google on this subject.

This impacts ALL file sharing based databases, Access, DB3, HFSQL Classic,...

You can only use these kind of database file access safely on local machines !

I don't know if this is the cause of your locking problem, but it would be wise to consider migrating to client/server.

Have a nice day
Danny
Publicado el 21,marzo 2016 - 12:11
Yogi,

I have a multi-user system installed with a customer using Windows 7 and HFSQL in Classic mode with the DB files in a shared folder and (touch wood), it's very reliable. As Danny mentions; are you using Windows Server or Windows 7/8/10?

The only difference with my implementation and yours is that I don't run the EXE from the "acting" server/PC. I ensure the EXE (system) is installed on each PC (including the "acting" server), and then the Project Code of each PC reads an INI file and issues a HChangeDir to point to the shared DB folder on the server.
Publicado el 21,marzo 2016 - 14:36
Hi Darren,

>> "...d), it's very reliable. ..."

I have heard that before, and then at some point, it just stops to be (a simple windows update on ANY of the computers involved can crash your system)...

So I -STRONGLY- suggest that you switch to C/S as soon as possible, BEFORE your client starts loosing data.

Best regards
Publicado el 21,marzo 2016 - 15:07
Yes Fabrice; agreed and they will be moving over to C/S very soon... I was only replaying my experiences of using Classic mode. I would be the first to agree that using Classic mode comes with it's risks but in certain cases, these risks can be managed. I'm by no means suggesting it was the "way to go". It's a matter of risk assessment; this customer will be bringing more users online soon and the new users will be "hitting" the same area of the database, thus increasing the potential for DB conflict... hence the move towards C/S - that's all :cheers:
Publicado el 25,marzo 2016 - 15:13
Thanks everyone for suggestions.

I think the problem is at record locking.

Will have to convert the software to HFSQL CS.

TIA

Yogi Yang