XALT is a lightweight software tool for any Linux cluster, workstation, or high-end supercomputer to track executable information and linkage of static shared and dynamically linked libraries. When the code is executed, wrappers intercept both the GNU linker (ld) and code launcher (like mpirun, aprun, or ibrun) to capture linkage information and environmental variables.

By surveying usage, administrators can use XALT to flag jobs that require the attention of support staff and deliver alerts to users pinpointing the causes of problems. The metrics produced as part of XALT's output data may be used to improve training, documentation, and research. Also, by tracking shared libraries required at link time, and then again at run time, an administrator can track the use of the shared libraries by their user community and detect when changes have occurred over time that might point to performance differences or a hacked SSL library.

Dr. Mark Fahey
Dr. Robert McLay

We wanted to be able to answer the questions: what software do researchers actually use on high-end computers, and how successful are they in their efforts to use it? With the information that xalt collects, high-end computer administrators can answer our questons by tracking continuous job-level information to learn what products researchers do and do not need. Drilling down to data driven usage statistics helps stakeholders conduct business in a more efficient, effective, and systematic way.

Ellexus is providing commercial support. See https://www.ellexus.com/products/xalt-tracking-job-level-activity-supercomputers if interested.

Documentation is provided at http://xalt.readthedocs.org as well as doc/XALTDesignandInstallationManual-0.5.pdf.

For quick installation instructions, see QUICK_INSTALL_GUIDE.TXT.

The XALT Design and Installation Manual-0.5 discusses the prerequisites for installation, decisions and considerations regarding database setup, XALT testing, other transmission methods, examples, and knowns issues.

The XALT Users Manual-0.5 describes how XALT is used in practice with further discusssion of database options, data transmission, creation of reverse maps, and examples with accompanying results for database queries.

1. With tools like the debugger Totalview, the debugger must interact with the job launcher rather than a wrapper. Two solutions currently exist: unload XALT when Totalview (or similar tools) are loaded OR edit the debugger wrapper to interact with the renamed job launcher. With either solution, Totalview runs will not show up in the XALT database.

2. Because the Cray compile wrapper uses a binutils linker, the Cray environment variable ALT_LINKER in the XALT modulefile must be set to point to the XALT wrapper.

Known issues are detailed in the XALT Design and Installation Manual-0.5.

To cite XALT, please use the following:

Agrawal, K., Fahey, M. R., McLay, R., & James, D. (2014). User Environment Tracking and Problem Detection with XALT. In Proceedings of the First International Workshop on HPC User Support Tools (pp. 32–40). Piscataway, NJ, USA: IEEE Press. http://doi.org/10.1109/HUST.2014.6

As part of the creation of XALT, data collected at the Texas Advanced Computer Center using XALT will be released for public use. Information about the dataset and links to the data may be found in the University of Texas TexasScholarWorks repository:

XALT data: http://web.corral.tacc.utexas.edu/XALT/
metadata: http://repositories.lib.utexas.edu/handle/2152/30535

To cite XALT data, please use the following:

McLay, Robert & Fahey, Mark R. (2015). Understanding the Software Needs of High End Computer Users with XALT. Texas Advanced Computing Center. http://dx.doi.org/10.15781/T2PP4P

XALT: A tool that tracks users jobs and environments on a cluster.
Copyright (C) 2013-2015 University of Texas at Austin
Copyright (C) 2013-2015 University of Tennessee

##License

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA