I was told I can add the -XX:+HeapDumpOnOutOfMemoryError parameter to my JVM start up options to my JBoss start up script to get a heap dump when we get an out of memory error in our application. I was wondering where this data gets dumped? Is it just to the console, or to some log … Read more
Are all of the following statements true? vector<Type> vect; //allocates vect on stack and each of the Type (using std::allocator) also will be on the stack vector<Type> *vect = new vector<Type>; //allocates vect on heap and each of the Type will be allocated on stack vector<Type*> vect; //vect will be on stack and Type* will … Read more
How can I check Heap Size (and Used Memory) of a Java Application on Linux through the command line? I have tried through jmap. But it gives info. about internal memory areas like Eden/ PermGen etc., which is not useful to me. I am looking for something like: Max Memory: 1GB Min Memory: 256 MB … Read more
This question already has answers here: What’s the relationship between “a” heap and “the” heap? (10 answers) Closed 10 months ago. Why are the runtime heap used for dynamic memory allocation in C-style languages and the data structure both called “the heap”? Is there some relation? 9 Answers 9
I’m new to Go and I’m experiencing a bit of cognitive dissonance between C-style stack-based programming where automatic variables live on the stack and allocated memory lives on the heap and Python-style stack-based-programming where the only thing that lives on the stack are references/pointers to objects on the heap. As far as I can tell, … Read more
I’ve heard the term “memory fragmentation” used a few times in the context of C++ dynamic memory allocation. I’ve found some questions about how to deal with memory fragmentation, but can’t find a direct question that deals with it itself. So: What is memory fragmentation? How can I tell if memory fragmentation is a problem … Read more
I have a production server running with the following flag: –XX:+HeapDumpOnOutOfMemoryError Last night it generated a java-38942.hprof file when our server encountered a heap error. It turns out that the developers of the system knew of the flag but no way to get any useful information from it. Any ideas? 7 Answers 7
I am working on a Windows 2003 server (64-bit) with 8 GB RAM. How can I increase the heap memory maximum? I am using the -Xmx1500m flag to increase the heap size to 1500 Mb. Can I increase the heap memory to 75% of physical memory (6 GB Heap)? 13 Answers 13
I am getting the following exception repeatedly each time I try to run the program. Error occurred during initialization of VM Could not reserve enough space for object heap Could not create the Java virtual machine. I tried to increase my virtual memory (page size) and RAM size, but to no avail. How can I … Read more
This question already has answers here: Error java.lang.OutOfMemoryError: GC overhead limit exceeded (22 answers) Closed 2 years ago. I am getting this error in a program that creates several (hundreds of thousands) HashMap objects with a few (15-20) text entries each. These Strings have all to be collected (without breaking up into smaller amounts) before … Read more
