Random errors/unstable when many instances/windows running

[wlasiukk]

Hi
When i run 6 instances of pl/sql developer (8.0.4) and trying run new one then very often this is impossible.
My computer have o lot of free ram, quad core but I can't run as many instances as I want.

When I close other instnace, or windows in other instances then I can run new instance or open new window.

 

[Marco Kalter]

We'll try to reproduce this.

 

[Worker]

What version of Windows?

What are the symptoms of "can't run a new instance"? What kind of "random errors" or "unstable" behavior do you see? After running 6 instances of pl/sql developer, can you run (multiple instances of) other large apps like Microsoft Word?

This may have something to do with running out of system resources. Specifically, windows only allocates a few MB of memory for GUI elements. Once that allocated memory is exhausted, even if you still have plenty of free RAM left, problems occur. If you'd like to know more, google "desktop heap".

 

[wlasiukk]

XP32 SP3

It looks like You are correct - used rate are quite high.
below - 4 instances are opened (~40 windows in them)

Desktop Heap Information Monitor Tool (Version 8.1.2925.0)
Copyright (c) Microsoft Corporation. All rights reserved.
-------------------------------------------------------------
Session ID: 0 Total Desktop: ( 5824 KB - 8 desktops)

WinStation\Desktop Heap Size(KB) Used Rate(%)
-------------------------------------------------------------
WinSta0\Default 3072 95.1
WinSta0\Disconnect 64 4.5
WinSta0\Winlogon 128 9.7
Service-0x0-3e7$\Default 512 32.8
Service-0x0-3e4$\Default 512 6.9
Service-0x0-3e5$\Default 512 8.3
SAWinSta\SADesktop 512 0.5
Service-0x0-23fdd9$\sbox_alternate_desktop_0x1294 512 41.7
-------------------------------------------------------------

Is there any way to workaround this problem ?

"random errors" or "unstable" means, thet i clik and nothing happends OR program hang OR error message show up. In really random fashion.

I will try this :http://blogs.msdn.com/b/tonyschr/archive/2005/05/25/desktop-heap-limitations.aspx

 

[Worker]

I've had the same problem with Windows XP in the past and have used the fix described behind your link. I have 2 GB of RAM and increased the desktop heap from 3 MB to 8 MB (8192) and haven't had any problems since. I read somewhere that the default for Windows Vista is 12 MB.

 

[wlasiukk]

After change WinSta0\Default to 6144 problem solved.

May be in next version there should be monitoring of free GUI resources ?