Application Slows down during user sessions (1 Viewer)

[cyberman55]

Running a split FE/BE application where the BE is on a storage server and each user has a local copy of the FE. It's a complicated app for estimating jobs with large tables. I've done what I can to minimize bloat and turned off transactions in all action queries as well as moving most SQL in code to queries. I can't induce the issue working on my development machine with the FE/BE both on my machine. Maybe I should set up a peer-to-peer network and put the BE on another machine here.

The client reports that the estimator screen is acceptably fast when first opened, but slows down considerably over time as they work with it. It eventually gets unacceptably slow and they have to exit the application and then reopen it to get back to useable speeds.

That estimator form has four subforms and the code refers to them when doing calculations. I tried late binding, but so much is going on during opening and during on_current events that I couldn't initially successfully do late binding. In any event (no pun), they have not reported any slowdown loading the form, just when they try to perform actions via buttons and combo boxes on the form(s).

I noticed a thread where Pat Hartman suggested each user having their own copy of the FE on the server in individual folders. Would moving the front ends to the same server as the back end help? Other thoughts?

 

[theDBguy]

Hi. Quick question... Are you using a persistent connection?

 

[gemma-the-husky]

Maybe you have a loop that is acquiring resources, but not releasing them, leading to some sort of "thrashing" type issue as resources get scarcer.

 

[cyberman55]

Hi. Quick question... Are you using a persistent connection?

Yes.

Maybe you have a loop that is acquiring resources, but not releasing them, leading to some sort of "thrashing" type issue as resources get scarcer.

That's my guess too, but despair as I don't know how to track it down. I did put debug.print statements in just about all form events (for the parent and subforms) and it looks like they are bouncing back and forth a bit before settling down and stopping. My Peter's software sizing code amplifies the effect a bit too. But the whole form settles down after a few "cycles". The user is running the network through Dell sonicwall devices which I think also acts as a router.

 

[isladogs]

In my opinion, giving each user a copy of the FE in individual folders in the server should only be done if there is no better solution.
It may possibly be useful for remote connections but in general it should be avoided because
1. It will probably be slower than users having the FE on their own workstation
2. Its much more work to setup/maintain

I had a similar situation in schools where at peak times such as am/pm registration, 100+ users simultaneously accessed the FE.
It slowed to a crawl and there were issues with some FEs getting corrupted.

The solution was to move the backend to SQL Server (or similar) which is much more secure / stable with a large user base.

In the meantime you may find this utility useful as a diagnostic tool Available Connections - Mendip Data Systems

 

[isladogs]

@cyberman55
You might want to look at my automatic form resizing code as an alternative. Its free!
In over 15 years of use with many thousands of users, I've never heard reports of it causing any performance issues such as you described.

For more info, see Automatic Form Resizing 1 - Mendip Data Systems