Skip to main content
A
Anonymous
June 14, 2007
Question

64 bit JRE = more RAM usage for JVM?

  • June 14, 2007
  • 5 replies
  • 1620 views
We are currently running a Windows 2003 Standard x64 Edition server, with a dual core AMD Opteron processor, and 8 GIGs of RAM. Our server runs over 20 newspaper websites, which when combined get a large amount of traffic. We are running ColdFusion MX7 on 64-bit IIS, using WOW64. I have noticed the JVM heap size of the server was only set to 1 GIG, so I tried to increase it. I found if I bumped it to anything over 1.3 GB, the ColdFusion service would fail to restart.

I have only found mention of this problem for 32-bit environments, however our environment is 64-bit. I believe the current JRE install is a 32-bit version. I am considering installing the Windows x64 Platform version (jre-6u1-windows-amd64.exe) from Sun Java, in attempt to increase the JVM Maximum Heap Size.

Does anyone know from experience if trying to install 64-bit JRE on a system that already has 32-bit JRE installed, will cause any problems? Assuming I got this to install, would this actually solve the heap size problem? I am hoping I can simply install the 64-bit JRE to a different location, point ColdFusion's JVM reference to the 64-bit version, increase the Maximum Heap Size to say 4 GIGs, restart the ColdFusion Application service, and ideally have everything work.

Any suggestions are welcome.

- Tim
    This topic has been closed for replies.

    5 replies

    A
    Anonymous
    June 21, 2007
    Transcon, since you're running multiple websites on that server, one thing you can do is use ColdFusion Enterprise Multi-Instance, and assign each website its own instance of CF. Each website would then have its own process, and you could use up to 1.3 GB of RAM for each one. Of course, given 20 websites, you probably won't want to allocate 26GB to the CF instances. Alternatively, you could create 5 or 6 instances of CF, and divide the websites up between them.

    It's a fair amount of work, but it would allow you to fully utilize your server's hardware, and as a bonus the websites would be a little more isolated from each other - i.e. if one of them crashed CF, not every site on the server would go down, only the ones in that instance.

    Interesting, and disappointing, news about CF8-64-win. I hope that can be rectified soon. If not, I may have to start playing with Solaris! Well, I've been meaning to play with ZFS anyway...
    A
    Anonymous
    June 15, 2007
    CF8 is only going to be supported on a 64 bit install on Solaris, if I recall correctly. It will NOT be supported on Windows. Apparently the runtimes are not where Adobe wants them to be with regards to 64 bit and Windows.

    This is per the CF8 feature tour I went to a month or so ago.
    N
    Newsgroup_User
    Inspiring
    June 14, 2007
    W_transcon wrote:
    > My current development machine is not 64-bit, so I can't do a test run without
    > doing it on the live server. I don't dare risk the down time. I am hoping
    > someone out there may have already tried this.
    >
    > Setting my max/min Heap size to 1.3 GB seems to be the best I can do. Combined
    > with the OS and other server resources, the server is still only using about
    > 2.25 GB of its 8 GB of RAM. I can't seem to bump up the heap size any higher,
    > because I believe there is a RAM limit set in the 32-bit JVM.
    >

    It was my understanding that MX 7 and earlier CF does not support 64 bit
    JVM's. I don't know about 8 yet.

    A
    Anonymous
    June 14, 2007
    My current development machine is not 64-bit, so I can't do a test run without doing it on the live server. I don't dare risk the down time. I am hoping someone out there may have already tried this.

    Setting my max/min Heap size to 1.3 GB seems to be the best I can do. Combined with the OS and other server resources, the server is still only using about 2.25 GB of its 8 GB of RAM. I can't seem to bump up the heap size any higher, because I believe there is a RAM limit set in the 32-bit JVM.
    N
    Newsgroup_User
    Inspiring
    June 14, 2007
    W_transcon wrote:
    >
    > Does anyone know from experience if trying to install 64-bit JRE on a system
    > that already has 32-bit JRE installed, will cause any problems?

    Just installing it won't cause problems.


    > I am hoping I
    > can simply install the 64-bit JRE to a different location, point ColdFusion's
    > JVM reference to the 64-bit version, increase the Maximum Heap Size to say 4
    > GIGs, restart the ColdFusion Application service, and ideally have everything
    > work.

    64-bit JVMs are not supported on Windows. It might still work though, I
    don't know. If you are not deterred by that, your best bet is to use it
    with an install that does not use any .dlls (no perfmon integration, no
    COM etc.).
    Please tell us about the result :)

    Jochem

    --
    Jochem van Dieten
    Adobe Community Expert for ColdFusion
    Terms & ConditionsAccessibility statement
    Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices