MPJ Express is an open source Java message passing library (like MPICH and OpenMPI) that allows application developers to write and execute parallel Java applications for multicore processors and compute clusters/clouds. The software is distributed under the MIT (a variant of the LGPL) license.
Questions tagged [mpj-express]
60 questions
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MPJ express: Inverse of a matrix implementation
I have to implement the inverse of a matrix algorithm using MPJ express. I succeeded in sending the transpose matrix and the determinant from rootProcess (rank=0) to the other processes.
The root process also assigns the lines interval for each…
lucian.marcuta
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Why does an exception occurs in the program which used MPJ Express?
There is a program that multiplies matrix and vector using MPJ Express. The matrix is divided by rows. But there is an exception occurs while processing. That am I doing wrong?
import java.util.Random;
import mpi.Comm;
import mpi.MPI;
public class…
Alexander Belenov
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mpj-express - summing an array using MPI
import mpi.*
public class Sum {
public static void main(String[] args) throws Exception {
String[] userArgs = MPI.Init(args);
int sum =0;
int [] partial_sum = new int [1];
int n;
int[]…
djacob
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1 answer
Exception while calling MPI.Init(args)
I started using MPJExpress recently on windows. Did all the configurations mentioned in the document for windows
Ran this small program :-
import mpi.*;
public class HelloWorld {
public static void main(String args[]) throws Exception {
…
aaditya chauhan
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Error while Running MPJExpress in cluster mode(niodev)
Well I know here is the similar question. However, no satisfactory answer is provided yet.
MPJ is working just fine on multicore platform.
But, when I tried running it on cluster using niodev mode(I exactly followed the mpjexpress user guide), I got…
user1612078
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3 answers
How Scatter and Gather works in MP J Express
I am to create a new cluster api for my project. So I started learning MP J Express these days.I just wrote program using Scatter and Gather in this way. But I am getting Null point exception.No idea where when wrong ?
Here is my code
import…
GPrathap
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I am getting this error when executing mpjboot on machines
i set MPJ_HOME in the environment variable and when i execute mpjboot machines i get this error
Error: MPJ_HOME environment variable not set!!!
java.lang.Exception: MPJ_HOME environment variable not set!!!
at…
1
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1 answer
Broadcasting a Better Value in MPI
I want to write a small program in MPI (Java implementation)
A variable x (double variable) is declared. Threads try to modify the variable (let's say a random modification). When a thread i finds a new value of X which is smaller than the older…
Study Learn
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MPJ Express -- runtime.MPJRuntimeException: Cannot connect to the daemon at machine and port <10000>
i am facing problem while configuring MPJ Express in cluster mode.
i am following the guide given at
http://mpj-express.org/docs/guides/linuxguide.pdf
the environment variables are successfully Initialized as
1)
Set MPJ_HOME and PATH variables
a. …
M Imtiaz
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Reading console input with mpj-express
I have to do an exercise for a parallel computing course. I used MPJ Express to distribute tasks to several processes (in my case 5 processes). I solved all the sub tasks, which are working fine. Now I want to implement a simple user dialog so that…
user1447713
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1 answer
MPI application freezes in cluster configuration using a big set of libraries
I have developed a MPI application using Java and MPJ Expresss. It works perfectly in the multi-core configuration.
Recently, it was given to my access to the distributed memory environment in order to test my application. First, I did the MPJ…
Rafael Angarita
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Why does it throw an exception when reading int array from file in java
I am trying to read an integer array from a file. the file format is as follows:
893
410
243
264
357
33
793
...
...
I will later split that array into 4 and calculate it's sum using MPI, but i can't seem to be able to read the file. I get this…
Zaka
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1 answer
How to solve "Connection refused" error in MPJ Express?
I run my MPJ program using 5 PCs with the same name (DESKTOP-J49PIF5) but it has different IP address. It run successfully in a laboratory. But when I tried to run the same program with the same configuration in a new laboratory (different place), I…
Edd
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Can not increase Java heap space in MPJ Express cluster mode
I executed my program using 5 nodes, each node equipped with 6 cores processor and 8GB of RAM. I set the process = 5 so that each node will handle 1 process. In some cases which used more data, I got an error "java.lang.OutOfMemoryError: Java Heap…
Edd
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How is the length determined in sendcount and recvcount in MPI.COMM_WORLD.Gather
So after I Bcast the data (clusters[10][5] 2d array) to every other process and then when each one calculates its new local values I want to send them back to the process 0.
But some of the data is missing sometimes (depends on no. of clusters) or…
gašper Sever
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