There are a number of useful diagnostic options that I haven't covered here.
For classpath JARs this is a big win: you don't have to scan a JarInputStream (or use a caching scheme) every time you need to load a class.
But there's a cost: memory-mapped files decrease the space available for the application heap and thread stacks.
To remove these capabilities at boot, add the previous two commands to your system startup scripts (eg /etc/rc.There are also a few named read-write segments here, associated with shared libraries; I believe that these hold the static data areas for those libraries, along with per-process relocation tables.One way to do this is to explicitly initialize all of your long-lived objects when the program starts, whether or not they're needed right away.In practice, the Sun JVM uses a fixed-size heap that's allowed to grow as needed between minimum and maximum bounds.Berrinam 24th March 2006, 09:36, i'm very glad that someone else found my work on source detection useful.Usually, the only reason that you'd look at a virtual memory map is to identify large chunks of memory used by direct buffers and memory-mapped files.#31: Editing without an editor Difficulty: Intermediate Application: Various Very long files are often hard to manipulate with a text editor.There are also kernel patches available for attribute support in XFS and ReiserFS.On a 64-bit JVM, the virtual address space is effectively unlimited; physical memory is the scarce resource.Some operating systems might also impose a hard limit on the number of threads that can be created for a single process.There's no way to make the JVM fail fast in this situation; at least on Linux, you can make a claim (via the -Xms and -Xmx parameters) on far more memory than can be supported.You can change this simply in the /etc/ssh/ssh_config file by adding the line: PermitRootLogin no Now the only way to get root privilges is through su, which means crackers now need to break two passwords to get full access.You can create a script to run this and generate a desktop image, which will change every day (or you can just use this method to generate images).The dump output gives you four pieces of information for each segment in the memory map: its virtual address, its size, its permissions, and its source (for segments that are loaded from a file).Java:188 The information is all there, but it's usually faster just to move shared libraries into the WAR/EAR until the problem goes away.
How many objects should be in the cache at any point in time?
If I was running out of memory, I'd try to find out where those strings were being allocated and why they weren't discarded.Firstly, the sxw file is a zip archive, so unzip it: unzip myfile.To remove the s bits of any tools that you don't use, type: chmod a-s program #57: Mac filtering Host AP Difficulty: Expert Application: iwpriv While you can certainly perform MAC filtering at the link layer using iptables or ebtables, it is far safer.So I've included some references at the end of this article.Tracing such chains from a histogram is a lot of work.This last indesign cs3 binle pdf includes a numeric variable, whose units are blocks of 5 seconds (for example, a value of 12 would equal one minute).