Access in Thin Client Environment (Access 2000 / Citrix XP MF)

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Has anyone had any experience of using Access under a thin client environment?

We’re using a number of multi-user Access applications and we’re constantly getting corruptions. This seems to be an issue with Access, as the http://www.Citrix.com[/url%5D message boards seem to be full of this issue! Unfortunately, no-one seems to know the best solution…

We’ve got a call logged, but if anyone has any recommendations for avoiding data corruption please let me know…..tired of doing repairs!

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In XP, use the ODBC Databases file type and you should see FoxPro among the listed ODBC types, assuming the drivers were installed on your machine.

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Thanks Charlotte, but how would this stop Access database corruption?? Does this driver cause problems under thin-client?

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ACKKHH!! That response got posted to the wrong thread!! I don’t know how I managed that, and it has nothing to do with Citrix. Apologies.

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ACKKHH!! That response got posted to the wrong thread!! I don’t know how I managed that, and it has nothing to do with Citrix. Apologies.

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Thanks Charlotte, but how would this stop Access database corruption?? Does this driver cause problems under thin-client?

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In XP, use the ODBC Databases file type and you should see FoxPro among the listed ODBC types, assuming the drivers were installed on your machine.

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Hi Dylan,

I presume you are using a single database with multiple users – if not give us more details about your configuration.
Our experience is primarily with Windows Terminal Services, but I understand it’s an economical version of Citrix. In any event, we found that unless you gave each user their own front-end in a split database arrangement, we also got frequent corruption. There are also other good reasons for splitting a database, but doing it in this envirnment seemed to solve most of our corruption problems, and in addition, when they did occur it usually only affected one user, and we simply replaces the front-end and they went back to work.

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Wendell,

Thanks for the reply….

Yes, our databases are split into FE/BE, we’re experiencing corruption in the back-end of the databases. We also have a single workgroup that we are using for all of our databases & the workgroup seems to be corrupting every now and then as well! Whenever a user then tries to access a table, they receive a ‘Disk or Network Error’. We get round the problem by kicking the users out of the problem database, then simply opening any database via the workgroup? It’s bizarre…

We’re getting the same thing with VB applications using Access as a back-end, the BE corrupts perhaps 3 or 4 times a week. The advice from Citrix seems to be use latest SP’s, lastest MDAC etc etc, but the servers are all bang up to date.

We have load balancing in place on the Farm, so users are connected to the least busy server when their desktop loads. This results in multiple servers accessing a single database BE & I’ve read on the Citrix.com forums that a single server should access a multi-user BE to avoid corruption? Is this a valid point…?

I’m sick of Citrix…..it’s a good idea in theory but causing so many problems…!

Thanks

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Hey Dylan,
We have used Citrix for about 4 years now. The configuration we use is a FE/BE like you are mentioning. How we handle the FE is that it resides on the server with the BE. In this mode we have had 25+ users banging the thing and it never failed. I can’t remember the last time we had a data corruption. One thing that seemed to help matters was that we made each user use a fresh copy of the FE each time they logged in. If this sounds interesting let me know and I will elaborate.

Thanks,
Mark Santos

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Hey Dylan,
We have used Citrix for about 4 years now. The configuration we use is a FE/BE like you are mentioning. How we handle the FE is that it resides on the server with the BE. In this mode we have had 25+ users banging the thing and it never failed. I can’t remember the last time we had a data corruption. One thing that seemed to help matters was that we made each user use a fresh copy of the FE each time they logged in. If this sounds interesting let me know and I will elaborate.

Thanks,
Mark Santos

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How many users are hitting a single BE – you probably should be looking at SQL Server if you are getting more than 5 or 10. As I understand it, any kind of hiccup in a Citrix session can potentially make Access think that a database is corrupt. SQL Server on the other hand is much more robust and should give you significantly better performance, as you don’t have to pull entire tables into the front-end. It could well be that you also have a slightly flakey network, and errors are occurring when you bring data from the single BE. Access is very sensitive to network errors.

One thing we always do is give each user their own copy of the security file (system.mdw), and we typically do it each time they reboot, unless we are using a deployment tool, in which case we let it decide when to deploy a new copy.

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Thanks for responses people…

Mark – yes, we have an application that does all of our database launching. Whenever they launch a DB from it, it will copy a new front end to a directory local to the user. This allows us to recompile a FE and have it easily redistributed to users next time they launch the DB. Has always worked a treat in the past…

Wendell – Yes I agree totally on the SQL Server point. I’ve just got my IT director to sign off a nice $30k server with all the trimmings…! Some of the databases have 10+ users and I know Access was never intended to be a fully fledged, multi-user data store, so I’ll be converting these to SQL once I get the hardware…

Our network could indeed be flaky, we have a number of different technologies (NT Server for databases, NAS for user directories & general storage) tied together with bits of string…

Each user having a copy of the workgroup is an interesting point, hadn’t considered. Thinking about it, this could well stop the file becoming corrupted…

Thanks again everyone, will post back if I have any joy…

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Once again, we have had 25+ people using the database simultaneously from around the world. What I mean by this is that we have had people from Munich, Rugby, Paris, Milan, Singapore, Japan, Taiwan, and the US using the DB at the same time using citrix. The key is to have the FE running on the same box as the BE. We never had a corruption as far as I could tell. Now, we eventually switched the BE to SQL server and that is surely the way to run long term. But you should be able to get acceptable performance until that time with 10+ users. Can you make it so that the FE resides on the server instead of the users local machine?

Thanks,
Mark

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If the FE runs on the same server as the BE, then how would each user get their own copy?

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Since they are using Citrix to run this app, each user is running a session of the app. Currently, we are running the same setup with up to 10 people hitting a 1 GHZ machine and it handles it no problem.

Thanks,
Mark

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But isn’t that the same as in a normal flat client environment? If the front end is run from a shared location you will get the problems that running the front end from a local location are meant to solve.

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With Citrix, each user gets their own virtual “desktop” running on the server. It’s as if separate computers are running for each user. We have had many problems with putting the FE on the users local machine and running the BE on a server. However, since running it with Citrix and having the FE on the server as well, there have been no problems. The FE is not shared, each user has their own folder with a copy of the FE for their use only. The server takes care of who gets what on what session.

Our DB is a customer service call tracking system. The database is being used non-stop all day by at least 6-8 users simultaneously. The actual number of users logged on is usually above 10 but the others are not entering data all of the time. At my last company, we had 25+ hitting it at once. Like mentioned earlier, SQL server is the better answer for groups of people using the DB. However, I still used citrix and the same FE configuration running that old DB.

Thanks,
Mark

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What we do is copy the front end to a personal folder on a different network drive to the back end rather than putting it in the local machine. I will try it out with the front end in the same location as the back end.

Does this mean however that users will be locking the front end database on the network? E.g., if we want to copy the latest FE each time the user runs it, will we still be able to do so if users have already opened it?

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Well, I am not sure what it is that you are doing exactly. Using Citrix is quite different then using a strait network location to run the FE. With citrix, the app runs entirely on the server, all the user sees is a screen snapshot of what the server is doing.

Thanks,
Mark

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Before Citrix, we had a FE and BE on a shared network location. Each time a user logged in, the FE was copied to a folder on the user’s personal network space, on a different server as it happens. The advantage with this method is any updates can be made to the FE in the shared location and the user will pick them up on the next log-in. I believe this is a standard recommended set up.

On Citrix, in theory it works the same.

We have a farm of around 15 Citrix servers, and users can be on any of these servers when opening the database. Incidentally, today we have had no corruptions (touch wood) since the network team changed the OpLocks setting on each server to pessimistic.

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Before Citrix, we had a FE and BE on a shared network location. Each time a user logged in, the FE was copied to a folder on the user’s personal network space, on a different server as it happens. The advantage with this method is any updates can be made to the FE in the shared location and the user will pick them up on the next log-in. I believe this is a standard recommended set up.

On Citrix, in theory it works the same.

We have a farm of around 15 Citrix servers, and users can be on any of these servers when opening the database. Incidentally, today we have had no corruptions (touch wood) since the network team changed the OpLocks setting on each server to pessimistic.

Reply | Quote

Well, I am not sure what it is that you are doing exactly. Using Citrix is quite different then using a strait network location to run the FE. With citrix, the app runs entirely on the server, all the user sees is a screen snapshot of what the server is doing.

Thanks,
Mark

Reply | Quote

What we do is copy the front end to a personal folder on a different network drive to the back end rather than putting it in the local machine. I will try it out with the front end in the same location as the back end.

Does this mean however that users will be locking the front end database on the network? E.g., if we want to copy the latest FE each time the user runs it, will we still be able to do so if users have already opened it?

Reply | Quote

With Citrix, each user gets their own virtual “desktop” running on the server. It’s as if separate computers are running for each user. We have had many problems with putting the FE on the users local machine and running the BE on a server. However, since running it with Citrix and having the FE on the server as well, there have been no problems. The FE is not shared, each user has their own folder with a copy of the FE for their use only. The server takes care of who gets what on what session.

Our DB is a customer service call tracking system. The database is being used non-stop all day by at least 6-8 users simultaneously. The actual number of users logged on is usually above 10 but the others are not entering data all of the time. At my last company, we had 25+ hitting it at once. Like mentioned earlier, SQL server is the better answer for groups of people using the DB. However, I still used citrix and the same FE configuration running that old DB.

Thanks,
Mark

Reply | Quote

But isn’t that the same as in a normal flat client environment? If the front end is run from a shared location you will get the problems that running the front end from a local location are meant to solve.

Reply | Quote

Since they are using Citrix to run this app, each user is running a session of the app. Currently, we are running the same setup with up to 10 people hitting a 1 GHZ machine and it handles it no problem.

Thanks,
Mark

Reply | Quote

If the FE runs on the same server as the BE, then how would each user get their own copy?

Reply | Quote

Once again, we have had 25+ people using the database simultaneously from around the world. What I mean by this is that we have had people from Munich, Rugby, Paris, Milan, Singapore, Japan, Taiwan, and the US using the DB at the same time using citrix. The key is to have the FE running on the same box as the BE. We never had a corruption as far as I could tell. Now, we eventually switched the BE to SQL server and that is surely the way to run long term. But you should be able to get acceptable performance until that time with 10+ users. Can you make it so that the FE resides on the server instead of the users local machine?

Thanks,
Mark

Reply | Quote

Thanks for responses people…

Mark – yes, we have an application that does all of our database launching. Whenever they launch a DB from it, it will copy a new front end to a directory local to the user. This allows us to recompile a FE and have it easily redistributed to users next time they launch the DB. Has always worked a treat in the past…

Wendell – Yes I agree totally on the SQL Server point. I’ve just got my IT director to sign off a nice $30k server with all the trimmings…! Some of the databases have 10+ users and I know Access was never intended to be a fully fledged, multi-user data store, so I’ll be converting these to SQL once I get the hardware…

Our network could indeed be flaky, we have a number of different technologies (NT Server for databases, NAS for user directories & general storage) tied together with bits of string…

Each user having a copy of the workgroup is an interesting point, hadn’t considered. Thinking about it, this could well stop the file becoming corrupted…

Thanks again everyone, will post back if I have any joy…

Reply | Quote

How many users are hitting a single BE – you probably should be looking at SQL Server if you are getting more than 5 or 10. As I understand it, any kind of hiccup in a Citrix session can potentially make Access think that a database is corrupt. SQL Server on the other hand is much more robust and should give you significantly better performance, as you don’t have to pull entire tables into the front-end. It could well be that you also have a slightly flakey network, and errors are occurring when you bring data from the single BE. Access is very sensitive to network errors.

One thing we always do is give each user their own copy of the security file (system.mdw), and we typically do it each time they reboot, unless we are using a deployment tool, in which case we let it decide when to deploy a new copy.

Reply | Quote

Wendell,

Thanks for the reply….

Yes, our databases are split into FE/BE, we’re experiencing corruption in the back-end of the databases. We also have a single workgroup that we are using for all of our databases & the workgroup seems to be corrupting every now and then as well! Whenever a user then tries to access a table, they receive a ‘Disk or Network Error’. We get round the problem by kicking the users out of the problem database, then simply opening any database via the workgroup? It’s bizarre…

We’re getting the same thing with VB applications using Access as a back-end, the BE corrupts perhaps 3 or 4 times a week. The advice from Citrix seems to be use latest SP’s, lastest MDAC etc etc, but the servers are all bang up to date.

We have load balancing in place on the Farm, so users are connected to the least busy server when their desktop loads. This results in multiple servers accessing a single database BE & I’ve read on the Citrix.com forums that a single server should access a multi-user BE to avoid corruption? Is this a valid point…?

I’m sick of Citrix…..it’s a good idea in theory but causing so many problems…!

Thanks

Reply | Quote

Hi Dylan,

I presume you are using a single database with multiple users – if not give us more details about your configuration.
Our experience is primarily with Windows Terminal Services, but I understand it’s an economical version of Citrix. In any event, we found that unless you gave each user their own front-end in a split database arrangement, we also got frequent corruption. There are also other good reasons for splitting a database, but doing it in this envirnment seemed to solve most of our corruption problems, and in addition, when they did occur it usually only affected one user, and we simply replaces the front-end and they went back to work.

Reply | Quote