On 06/07/10 02:47 AM, Stan Hoeppner wrote:
Motherboard: Gigabyte MA790GPT-UD3H. Chipset: AMD 790GX/SB750 Onboard graphics: ATI Radeon HD 3300 Graphics Audio chipset: Realtek ALC889A LAN: Gigabit, Realtek 8111C
Presently I am using onboard graphics, but till a few weeks ago I was using a PCIe Nvidia graphics card and the computer was still freezing the same way.
I am having a problem with Apache 2.My all websites were in accessible for some time. There is no application/user on these websites and no database also. The debug mode logging is on what should I check in from the log I am not able to understand any thing in logs.
In top, my java processes all show an average VIRT size of about 250MB and an average RES size of about 150MB. Most of them were started with a 64MB heap size. I have two questions:
1. Top shows 0k of swap usage, so the system is not swapping. In that case, why is there a difference between the VIRT and RES numbers? My understanding is that RES=CODE+DATA and VIRT=RES+SWAP. If swap=0, then should not RES and VIRT be the same?
2. Where does the 64MB of java heap show up?
Hi,
Sorry if it is a FAQ,
Is the 3G memory access limit is the natural one, or something superficial imposed by M$? I mean, does 32bits Linux (the i386 architecture) has such 3G limit as well?
thanks
We run 150+ instances of tomcat on one server. To optimize memory utilization, each tomcat instance is configured with 64MB by default (export JAVA_OPTS=”-ms64M -mx64M”). We then watch for Java.Lang.OutOfmemory errors in the logs. If we see any of these over time, we allocate additional RAM in 32MB increments until that instance stops throwing errors. Most instances are happy with 64MB. Some need 96MB or 128MB. We have never seen a tomcat instance that throws OutOfMemory errors with 256MB RAM.
If tomcat is not throwing OutOfMemory errors and system responsiveness is good, is there really any reason to allocate higher amounts of RAM?
On 13/06/2010 16:27, andy susanto wrote:
Windows what? 95? 98? 2000?
The server has 1Gb of hardware RAM? That’s not very much…
5.0.something or 5.5.something?
How much memory is mysql using?
p
On Sat, Jun 12, 2010 at 1:19 AM, Sean Conner wrote:
Thanks for the information. From this I gather I’m more interested in the overall memory usage of the server than that of apache itself. So I’ll use those numbers.
Regards Bram
It was thus said that the Great Bram Mertens once stated:
It’s not easy. For example, one instance of Apache on my server (running Lniux) is showing it’s using 11M of memory (output of “ps aux”, which includes memory usage of each process), of which only 6M is actually in it’s “resident set size”, which according to the documentation for “ps”:
resident set size, the non-swapped physical memory that a task has used.
But of that 11M, a good portion of it is shared between *all* the instances of Apache—the actual code portion is shared between the Apache processes, and any data that actually hasn’t been changed since a given child process started is at least shared with the parent (or main) process [1]. I’m not aware of any easy way to determine the amount of non-shared writable memory in a process. That would be my guess.
-spc
[1] Linux, as well as many other Unix operating systems, use a concept of “copy-on-write.” Memory is broken up into what are called “pages”—typically around 4k each and each 4k chunk is made visible (or “mapped”) to a process. When a process creates a child process, all the memory pages of the parent are visible to the child, but they’re marked “read-only” at this point. Reguardless of who writes some data, the operating system can detect this (since the page is “read-only” and all writes are trapped), that page is then duplicated, so there are now two pages in memory with the same content. One page is mapped into the parent and made read-write, and the other one is mapped into the child and made read-write [2]. Now each process has their own private copy of just that one page.
It wouldn’t surprise me if Windows works simularly, but since I don’t use Windows, I can’t say for sure.
[2] It doesn’t matter which is mapped since the instruction that did the write will be re-executed anyway.
Hi,
I have a question on how IndexWriter manages its memory when it comes to RawPostingList. Its pretty late, so sorry if the question is obvious, but the question is when does the RawPostingList array gets reclaimed or shrinked? I assume they get factored in the ram balancing process, but, is there a chance that they won’t be reclaimed? Can I force them to be reclaimed, I think that IndexWriter#commit does not affect that… . Here is a link to a sample heap dump I took (I do call flush): http://skitch.com/kimchy/dg3e4/eclipse-memory-analyzer.
Thanks, Shay
On Thu, June 3, 2010 10:40, Merciadri Luca wrote: This might be what you are looking for: http://mozillalinks.org/wp/2009/07/vacuum-your-firefox-databases-for-better-performance/ Cleaning up firefox/iceweasel’s internal databses helps a lot.
Kind regards, Steven