- Infos im HLRS Wiki sind nicht rechtsverbindlich und ohne Gewähr -
- Information contained in the HLRS Wiki is not legally binding and HLRS is not responsible for any damages that might result from its use -

Darshan

From HLRS Platforms
Revision as of 17:24, 26 November 2021 by Hpcanmac (talk | contribs)
Jump to navigationJump to search

Note: This page is in progress.

Darshan is a set of libraries that can characterize MPI-IO and POSIX file access within typical HPC applications in a nonintrusive way. It can be used to investigate I/O behavior of a MPI-program.
Developer: Argonne National Laboratory
Platforms: HPE_Hawk
Category: Performance Analyzer
License: free software
Website: Darshan homepage


Introduction

Darshan is developed by Mathematics and Computer Science Division of Argonne National Laboratory to allow investigation and tuning of the I/O behaviour of complex HPC applications. It is open-source and available on github. Many Tutorials and hands-on excercises are available online.

Usage

Darshan can be used with compile time wrappers or by dynamic library preloading. For detailed description, see 'Darshan-runtime installation and usage'.

Running program with Darshan instrumentation on Hawk using module

In Hawks module environment Darshan version 3.1.7 is available. If you need a different version you can install it in your home directory and follow the description mentioned above.

The easiest way to instrument your application is to preload the darshan library during runtime. You have to make sure your application is dynamically linked with the MPI library. If you are not sure if it is dynamically linked, type

ldd your_application

If it shows the MPI library, your application is dynamically linked.

libmpi.so => /opt/hpe/hpc/mpt/mpt-2.23/lib/libmpi.so (0x00007f5d32b33000)

Load the needed software module,

module load darshan-runtime

create directory to store Darshan logfile. It should have the folder structure year/month/day.

mkdir -r "$(date +"%Y")"/"$(date +"%m")"/"$(date +"%d")"

Export logpath environment variable,

export DARSHAN_LOGPATH=.

run your application with preloaded darshan library.

LD_PRELOAD=/opt/hlrs/spack/rev-004_2020-06-17/darshan-runtime/3.1.7-gcc-9.2.0-a2f i2dv3/lib/libdarshan.so mpirun -np 128 ./your_application

You will get a darshan logfile in the previously created directory. Its name will have your username, your application name and a bunch of numbers in it and go with the ending .darshan.

Parsing log file to pdf

See also

External Links