[Geoserver-users] Same Configuration, Different computer, very slow

GeoServer GeoServer User
1

Yep, every 64-bit address is twice as long as a 32-bit address. 2Gb address
space can be addressed with 32-bit, hence using 64-bit you have a lot of
waste just for addressing your objects.

I doubt that you have only 2Gb RAM on your Mac. So, 64-bit systems are a
complete waste and usually slower, if you want to assign only 2 Gb of RAM.
With larger memory spaces a 64-bit system will fly.

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Dr Christian Maul
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Information Services Branch
Department of Sustainability and Environment
Level13, Marland House, 570 Bourke Street
Melbourne 3000

PO Box 500, East Melbourne Vic 3002

Telephone: +61-3-8636 2325
Telefax: +61-3-8636 2813
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2

[The original post is by a nonsubscriber and can seen on nabble]
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Original poster, please subscribe to this list or your posts will not be delivered. (You were just lucky that Christian reads via nabble and was kind enough to respond.)

On 25/01/13 13:00, cmaul wrote:

Yep, every 64-bit address is twice as long as a 32-bit address. 2Gb address
space can be addressed with 32-bit, hence using 64-bit you have a lot of
waste just for addressing your objects.
I doubt that you have only 2Gb RAM on your Mac. So, 64-bit systems are a
complete waste and usually slower, if you want to assign only 2 Gb of RAM.
With larger memory spaces a 64-bit system will fly.

I am not sure 64-bit is the problem. Both machines are using 64-bit.

Since Java 6u23, 64-bit (amd64) Oracle VMs default to using Compressed OOPs, which combine the memory size advantage of 32-bit pointers with the performance advantage of the amd64 instruction set and only a slight overhead:
http://docs.oracle.com/javase/7/docs/technotes/guides/vm/performance-enhancements-7.html#compressedOop

64-bit VMs are slower on startup because they only support server mode, which is optimized for maximum performance for long-running applications; tiered compilation reduces this overhead but it is still there for short-running applications.

Back to the original question:

The two Windows Server 2008 machines are running in two different virtualisation implementations, one fast in parallels on a mac (WS2008 R2) and one unexpectedly slow in vmware on a non-mac (WS2008 not R2). Both 64-bit Java 6.

Have you tried running them both on the same virtualisation implementation, on the same hardware? This would be a direct test of R2 versus non-R2.

Performance of virtual machine systems can vary wildly, depending on host factors such as filesystem virus scanning on the host, host hardware (HDD versus SSD), host filesystem type (HFS, NTFS, ext4), hardware virtualisation support such as VT-x and VT-d, and host software implementation. Best to compare apples with apples by comparing R2 and non-R2 on the same machine with the same virtualisation implementation.

What version of VMWare are you using?

Kind regards,

--
Ben Caradoc-Davies <Ben.Caradoc-Davies@anonymised.com>
Software Engineer
CSIRO Earth Science and Resource Engineering
Australian Resources Research Centre

3

I’m not sure that was the problem in my case. What I realized was that my Mac Pro is SSD, which does not page fault thus no disk thrashing. I believe this is a large part of the problem, but still have many questions.

How do you retain more geocache tiles in memory to avoid hard disk thrashing?

Should I need geocache at all for a 700 mb geotiff?

  • Brad Bode
    Sent from iPhone so please ignore all shrthnd and spelling errers.

On Jan 24, 2013, at 9:00 PM, “cmaul [via OSGeo.org]” <[hidden email]> wrote:

Yep, every 64-bit address is twice as long as a 32-bit address. 2Gb address space can be addressed with 32-bit, hence using 64-bit you have a lot of waste just for addressing your objects.

I doubt that you have only 2Gb RAM on your Mac. So, 64-bit systems are a complete waste and usually slower, if you want to assign only 2 Gb of RAM. With larger memory spaces a 64-bit system will fly.

Dr Christian Maul
Project Manager

Information Services Branch
Department of Sustainability and Environment
Level13, Marland House, 570 Bourke Street
Melbourne 3000

PO Box 500, East Melbourne Vic 3002

Telephone: +61-3-8636 2325
Telefax: +61-3-8636 2813

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4

Ill have to find out what VMware version we are using. However, I have found
out more. For starters I switched to 32 bit tomcat and JVM so I could make
use of JAI. Then I had our VM upgraded to R2. So now I have:

Computer 1 - Mac Pro SSD with 16 gig of ram but only 3 allocated to the
parallels VM I am running Geoserver on. Windows server 2008 R2.

Computer 2 - dell server with 6 gig ram allocated to windows server R2 vM.
Raid 5 HD.

And now a 3rd computer that fails all the time. Tomcat literally chokes and
died on image processing if I stress Geoserver. This computer is a dell 4
core 2.6 ghz server with 16 gig of ram. It should not die. But as far as I
can tell its due to disk thrashing. I can replicate this every time I use
tiling via a WMS request at a rapid pace. (One user scrolling through tiles
and different zoom levels rapidly).

The graphics card on computer 3 isn't that impressive. And the disk is the
least capable in terms of performance. If I watch the Perfmon stats the
disk IO goes nuts despite caching enable for tiles.

Thoughts?

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5

On Fri, Jan 25, 2013 at 6:54 AM, ForBode <cabaal@anonymised.com> wrote:

I’m not sure that was the problem in my case. What I realized was that my Mac Pro is SSD, which does not page fault thus no disk thrashing. I believe this is a large part of the problem, but still have many questions.

How do you retain more geocache tiles in memory to avoid hard disk thrashing?

You don’t, GeoWebCache serves exclusively from disk. I haven’t tried, but I would’nt
be surprised if GeoWebCache is in excess of 50% faster on Linux than on Windows.
Tests in the past showed that GeoServer is 30% faster on Linux, and GeoServer is not nearly
as affected as GeoWebCache by the disk performance

Cheers
Andrea

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