Mindprod points out that this is not a straightforward question to answer: A JVM is free to store data any way it pleases internally, big or little endian, with any amount of padding or overhead, though primitives must behave as if they had the official sizes. For example, the JVM or native compiler might decide … Read more
You can get some limited memory information from the Runtime class. It really isn’t exactly what you are looking for, but I thought I would provide it for the sake of completeness. Here is a small example. Edit: You can also get disk usage information from the java.io.File class. The disk space usage stuff requires … Read more
this may not be accurate but its close enough for me long size = 0; object o = new object(); using (Stream s = new MemoryStream()) { BinaryFormatter formatter = new BinaryFormatter(); formatter.Serialize(s, o); size = s.Length; }
The guarantee you get is that sizeof(char) == 1. There are no other guarantees, including no guarantee that sizeof(int *) == sizeof(double *). In practice, pointers will be size 2 on a 16-bit system (if you can find one), 4 on a 32-bit system, and 8 on a 64-bit system, but there’s nothing to be … Read more
Heap memory The heap memory is the runtime data area from which the Java VM allocates memory for all class instances and arrays. The heap may be of a fixed or variable size. The garbage collector is an automatic memory management system that reclaims heap memory for objects. Eden Space: The pool from which memory … Read more
Imagine that you have a “large” (32 bytes) expanse of free memory: ———————————- | | ———————————- Now, allocate some of it (5 allocations): ———————————- |aaaabbccccccddeeee | ———————————- Now, free the first four allocations but not the fifth: ———————————- | eeee | ———————————- Now, try to allocate 16 bytes. Oops, I can’t, even though there’s nearly … Read more
use quick tip using top command in linux/unix $ top and then hit Shift+m (i.e. write a capital M). From man top SORTING of task window For compatibility, this top supports most of the former top sort keys. Since this is primarily a service to former top users, these commands do not appear on any … Read more
The memory subsystem on a modern processor is restricted to accessing memory at the granularity and alignment of its word size; this is the case for a number of reasons. Speed Modern processors have multiple levels of cache memory that data must be pulled through; supporting single-byte reads would make the memory subsystem throughput tightly … Read more
The best script I found is on this page : http://northernmost.org/blog/find-out-what-is-using-your-swap/ Here’s one variant of the script and no root needed: #!/bin/bash # Get current swap usage for all running processes # Erik Ljungstrom 27/05/2011 # Modified by Mikko Rantalainen 2012-08-09 # Pipe the output to “sort -nk3” to get sorted output # Modified by … Read more
The error shows that the machine does not have enough memory to read the entire CSV into a DataFrame at one time. Assuming you do not need the entire dataset in memory all at one time, one way to avoid the problem would be to process the CSV in chunks (by specifying the chunksize parameter): … Read more