Strange Slow Network Problem

[pinzgauer]

I have a standard database with a 2 workstations and a server. If I start up the database on a workstation and execute a script wit a query
it takes 2 seconds for the result browse to show. If I start up the database on a second computer the query will take 20 seconds.
The database is password protected. I don't even have to go passed the password screen and it already slows the first computer.
I don't use Network Optimization.

Full Version on Server and Runtime on workstations

Thanks in advance

[Ted Giles]

Re: Strange Slow Network Problem

Try optimisation.
Each call to the server will be sending everything including forms and logos. You really only want the data, so that is what optimisation is all about.
You can always back out.

[pinzgauer]

Re: Strange Slow Network Problem

Optimization can not be used with a attached table that is not in the database folder. I have a hidden Network drive (NAS) for the most sensitive data for security reason.
The problem is not the network speed but the slowing when two or more users are connected

[Tom Cone Jr]

Re: Strange Slow Network Problem

Willy,

Is the same slowing performance evident regardless of which machine starts first?

[amorris]

Re: Strange Slow Network Problem

Willy,

You can shadow the tables/adb and still have a table on a server somewhere. You just have to make sure the table is included in the adb after shadowing or there is a correct path to attached the data for lookup or whatever you are doing with it.

It is no different than others here who have a table on a workstation that is not on the server, but is used by the person at that workstation.

[Tom Cone Jr]

Re: Strange Slow Network Problem

Willy,

I think NAS devices are optimized for writes, but not reads. Are you pulling data from the NAS when you run your slower queries? It would be interesting to know whether the performance issue gets resolved if you didn't use the NAS device by moving the table into your database folder.

Have you confirmed that there are no real-time antivirus / malware processes running to protect the server data folders?

[pinzgauer]

Re: Strange Slow Network Problem

I shadowed the database, detached the dbf on the NAS from the set, made sure no antivirus is running on the database but the query delay is still the same.

[amorris]

Re: Strange Slow Network Problem

Willy,
Sounds like a real network problem.
weak card,
bad connection,
weks/bad hub/switch,
wire,
not enough memory on server,

I am sure you checked fo very large fpt files in the folder, have gone over your indexes and compacted the workspace?

If all this is done, can we see the query code?

[pinzgauer]

Re: Strange Slow Network Problem

As I said on the first post the query is the same speed on any network station as it is on the server as long as there is just one computer connected to the database.
This is in my opinion not a network problem.

[Ted Giles]

Re: Strange Slow Network Problem

Full Version on Server and Runtime on workstations

Is the Runtime version the same as the Development version?

[csda1]

Re: Strange Slow Network Problem

Hi Willy,

I have a standard database with a 2 workstations and a server. If I start up the database on a workstation and execute a script wit a query
it takes 2 seconds for the result browse to show. If I start up the database on a second computer the query will take 20 seconds.

There are 3 kinds of access that a database may be used on the network. Exclusive access, shared access but sole use by one thread of Alpha Five (or could be some other program, but that's not relavant here), and shared access with multiple users. It can easily drop to 1/10th the speed if you start sharing the database over a network. That is why LQO and efficient query techniques are so important.

It also might have helped if you told us how many records were being queried, and whether it was employing LQO and or an index.

And it's not impossible that network settings on the workstations and/or server can affect the speed of record access. I suggest reading some of my Network Issues related to speed tips and Record Locking 101 tips

[pinzgauer]

Re: Strange Slow Network Problem

I am not using LQO about 20000 records. So you are saying this is a normal slow down. If this is the case I will try to speed it up with LQO and other methods.
How can I determine the access method used and which one should I choose. We have a 3 user setup with one on the server. And yes all three alpha versions are the same.

Thanks Willy

[csda1]

Re: Strange Slow Network Problem

Hi Willy,

I am not using LQO about 20000 records. So you are saying this is a normal slow down. If this is the case I will try to speed it up with LQO and other methods.
How can I determine the access method used and which one should I choose. We have a 3 user setup with one on the server. And yes all three alpha versions are the same.

You should read up on LQO and how it gets invoked. You can't tell if it will be used, except by the resultant speed.

It requires an index with an expression that at least partially matches the expression of the query. If you are using a query that came from a query by form or other automated method, it most likely does not have an expression of the correct form. LQO basically works by placing an implied range on the index. So if you are looking for people whose last names start's with "S", it only looks at those records that start with "S", not all 20000 records. That is why it is so important to use (despite the fact that most don't)

1000 records/sec is pretty good for processing I'd say on a network. I trust you are running a fast network, say 1 Gig wired as opposed to wireless?

And there are also lots of tricks and methods you can apply that can speed up processing, but that is something that takes time to learn.

[pinzgauer]

Re: Strange Slow Network Problem

It is still strange to me that a query from a network station will slow down so dramatically, when a second computer has not even gone past the log in screen of the database.

Willy

[amorris]

Re: Strange Slow Network Problem

It is still strange to me that a query from a network station will slow down so dramatically, when a second computer has not even gone past the log in screen of the database.

This is why I suggested a hardware problem in an earlier post. One weak/bad network card in any one computer has caused this in the past. Yes, I know you said to rule out your network and you may be correct. but it keeps coming to the fron.

Basically 4 things
problem with network hardware or setup - needs testing.
bad programming - let others test/check it for you - the smallest mistake can make the greates difference at times including lqo.
Other traffic on the network - other computers/applications doing heavy downloads/uploads.
Needs more memory on the server and/or work stations.

In other words your slowdowns are not the norm.

You could make a quick/small app on your server and try it with a shadow on the other 2 computers to see if it also has problems?