Performance discrepancy between two boxes on an active/active?

Performance discrepancy between two boxes on an active/active?

Post by M Bourgo » Tue, 25 Mar 2008 11:46:54


Howdy. I'm running an Active/Active cluster on a SQL Server 2005
cluster. Both have identical hardware, and obviously the same disks.
One really odd thing I'm seeing, though: the first Active node,
running on the first box, sucks. When trying to connect, list SPs,
"wait 2 minutes to view a job",etc. However, when we recently ran
both instances on the second box, the performance seems much snappier.

Where should I be looking to try and figure out what's causing this?
Neither node is running extra software the other isn't. But
something's going on.

Thanks.
 
 
 

Performance discrepancy between two boxes on an active/active?

Post by Tom Morea » Tue, 25 Mar 2008 11:58:49

Just a shot in the dark here. Are you using AWE on a 32-bit box? If so,
could you check the BOOT.INI file on each box and ensure that /PAE is in
both?

--
Tom

----------------------------------------------------
Thomas A. Moreau, BSc, PhD, MCSE, MCDBA, MCITP, MCTS
SQL Server MVP
Toronto, ON Canada
https://mvp.support.microsoft.com/profile/Tom.Moreau




Howdy. I'm running an Active/Active cluster on a SQL Server 2005
cluster. Both have identical hardware, and obviously the same disks.
One really odd thing I'm seeing, though: the first Active node,
running on the first box, sucks. When trying to connect, list SPs,
"wait 2 minutes to view a job",etc. However, when we recently ran
both instances on the second box, the performance seems much snappier.

Where should I be looking to try and figure out what's causing this?
Neither node is running extra software the other isn't. But
something's going on.

Thanks.

 
 
 

Performance discrepancy between two boxes on an active/active?

Post by M Bourgo » Tue, 25 Mar 2008 13:25:48


Good idea - hadn't thought of that. However, because of the hardware
they both have PAE turned on, despite the boot.ini (just checked, by
right-clicking on My Computer and choosing properties). I've included
it below, just in case. Both machines are Microsoft Windows Server
2003, Enterprise Edition, SP1.

First Box:
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(2)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Windows Server 2003,
Enterprise" /noexecute=optout /fastdetect


Second Box:
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(2)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Windows Server 2003,
Enterprise" /noexecute=optout /fastdetect
 
 
 

Performance discrepancy between two boxes on an active/active?

Post by M Bourgo » Tue, 25 Mar 2008 13:26:23


Oh, and yes, both are 32bit, using AWE.
 
 
 

Performance discrepancy between two boxes on an active/active?

Post by Tom Morea » Tue, 25 Mar 2008 20:07:40

Both of these are not using the /PAE switch. Thus, you're not using AWE.

--
Tom

----------------------------------------------------
Thomas A. Moreau, BSc, PhD, MCSE, MCDBA, MCITP, MCTS
SQL Server MVP
Toronto, ON Canada
https://mvp.support.microsoft.com/profile/Tom.Moreau






Good idea - hadn't thought of that. However, because of the hardware
they both have PAE turned on, despite the boot.ini (just checked, by
right-clicking on My Computer and choosing properties). I've included
it below, just in case. Both machines are Microsoft Windows Server
2003, Enterprise Edition, SP1.

First Box:
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(2)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Windows Server 2003,
Enterprise" /noexecute=optout /fastdetect


Second Box:
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(2)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Windows Server 2003,
Enterprise" /noexecute=optout /fastdetect
 
 
 

Performance discrepancy between two boxes on an active/active?

Post by M Bourgo » Wed, 26 Mar 2008 01:18:45


Are you sure about that? I show each is using the right amount of
memory (8gb and 6gb of RAM), the System Properties screen says PAE,
and you don't have to explicitly state /PAE if your system supports
data execution prevention.

http://www.yqcomputer.com/
The PAE kernel can be enabled automatically without the /PAE switch
present in the boot entry if the system has DEP enabled (/NOEXECUTE
switch is present) or the system processor supports hardware-enforced
DEP. Presence of the /NOEXECUTE switch on a system with a processor
that supports hardware-enforced DEP implies the /PAE switch. If the
system processor is capable of hardware-enforced DEP and the /
NOEXECUTE switch is not present in the boot entry, Windows assumes /
NOEXECUTE=optin by default and enables PAE mode. For more information,
see the topic "Boot Options in a Boot.ini File" in the Windows DDK.
 
 
 

Performance discrepancy between two boxes on an active/active?

Post by Tom Morea » Wed, 26 Mar 2008 01:34:49

OK. How much RAM do these servers have?

--
Tom

----------------------------------------------------
Thomas A. Moreau, BSc, PhD, MCSE, MCDBA, MCITP, MCTS
SQL Server MVP
Toronto, ON Canada
https://mvp.support.microsoft.com/profile/Tom.Moreau






Are you sure about that? I show each is using the right amount of
memory (8gb and 6gb of RAM), the System Properties screen says PAE,
and you don't have to explicitly state /PAE if your system supports
data execution prevention.

http://www.yqcomputer.com/
The PAE kernel can be enabled automatically without the /PAE switch
present in the boot entry if the system has DEP enabled (/NOEXECUTE
switch is present) or the system processor supports hardware-enforced
DEP. Presence of the /NOEXECUTE switch on a system with a processor
that supports hardware-enforced DEP implies the /PAE switch. If the
system processor is capable of hardware-enforced DEP and the /
NOEXECUTE switch is not present in the boot entry, Windows assumes /
NOEXECUTE=optin by default and enables PAE mode. For more information,
see the topic "Boot Options in a Boot.ini File" in the Windows DDK.
 
 
 

Performance discrepancy between two boxes on an active/active?

Post by M Bourgo » Wed, 26 Mar 2008 02:40:44


16gb each, but we have the amounts capped to 8gb and 6gb, so that if
they're on the same box, we don't have memory issues.
 
 
 

Performance discrepancy between two boxes on an active/active?

Post by Tom Morea » Wed, 26 Mar 2008 03:18:50

Well, things look OK there. On the box that's slow, I'd be tempted to put
in the /PAE switch explicitly, just to see if it is taking you seriously on
the DEP thing.

Also, what happens when you run just one instance on that box? Is the
performance OK? If not, what happens when you crank up the memory for that
one instance (temporarily)?

--
Tom

----------------------------------------------------
Thomas A. Moreau, BSc, PhD, MCSE, MCDBA, MCITP, MCTS
SQL Server MVP
Toronto, ON Canada
https://mvp.support.microsoft.com/profile/Tom.Moreau






16gb each, but we have the amounts capped to 8gb and 6gb, so that if
they're on the same box, we don't have memory issues.