The University of Luxemburg Gaia Cluster log

System: University of Luxemburg Gaia Cluster
Duration: May to August 2014
Jobs: 51,987

This log contains 3 months worth of data from the Gaia cluster at the University of Luxemburg. It is used mainly by biologists working with large data problems and engineering people working with physical simulations.

The workload data includes CPU and memory usage, and also I/O activity in a separate file (as I/O is not accommodated by the standard workload format).

The workload log from the Gaia cluster system was graciously provided by Joseph Emeras ( If you use this log in your work, please use a similar acknowledgment.


UniLu-Gaia-2014-1.swf 0.8 MB gz original converted log as received
UniLu-Gaia-2014-2.swf 0.9 MB gz re-converted log
(May need to click with right mouse button to save to disk)

Papers Using this Log:

This log was used in the following papers:

System Environment

The Gaia cluster is one of the 4 clusters operated by the ULHPC (University of Luxembourg HPC Center). Initially released in 2011, Gaia is now a heterogeneous cluster that has been upgraded several times. It currently feature 151 nodes, manufactured by Bull and Dell, with a total of 2004 cores. Several nodes (20) feature NVidia Tesla-class GPGPUs accelerators.

Full details about its configuration and history are available from the University of Luxemburg site.

The scheduler used is OAR (

Log Format

The log is available directly in SWF. It is based on accounting data collected by the scheduler.

In addition, a companion log with I/O data is available. For each job, it lists the total amount of data read and written by all the processes of this job. The job ID field is the same as in the SWF files, to enable merging the data.

Conversion Notes

There is no data about any problems in the conversion process.

Nevertheless, an SWF parser (customized for this log) was used in conjunction with a general converter module to check the file. The following anomalies were observed and in some cases corrected:

Usage Notes

Due to the heterogeneity of the cluster it is not clear that all jobs received the same level of service. This may affect their wait times and maybe also the activity patterns of certain users.

Activity in the first 4-5 days is very low and probably reflects remnants of activity from before logging actually started.

There appears to be a flurry by user 8 towards the end of the log; this has not been cleaned yet.

The Log in Graphics

File UniLu-Gaia-2014-2.swf

weekly cycle daily cycle burstiness and active users job size and runtime histograms job size vs. runtime scatterplot utilization offered load performance

Parallel Workloads Archive - Logs