A German scientific institute migrated to Linux and open-source software to monitor global seismic activity data for compliance with the nuclear test ban treaty.
By Tina Gasperson
A German scientific research institute is using an open-source database running on Linux and x86 hardware to store global seismic activity data and to interpret that data. The purpose is to ensure that countries around the world are in compliance with the terms of the nuclear test ban treaty.
The CTBTO calls for global monitoring to ensure compliance with the treaty. Monitoring stations worldwide use infrasound, hydroacoustic and radionuclide technologies. It also tests for underground movement that is usually associated with earthquakes, called seismic activity, to ensure that no country can get away with secret underground nuclear testing.
The BGR, an official primary seismic monitoring station for the CTBTO, oversees the activities of four seismic monitoring stations (of about 50), keeping track of all kinds of seismic activity and interpreting the results. The BGR stores the data in a database used by CTBTO member nations to determine compliance with the terms of the Nuclear Test Ban Treaty. The BGR also monitors natural seismic activity that occurs in conjunction with earthquakes, including the recent 7.9-magnitude quake that rocked China’s Sichuan Province in May.
The BGR was a longtime Sun SPARC and Solaris customer, using the Ingres database to store data retrieved from instruments that monitor global seismic activity. “The database is used to store evaluations of seismic waveform data from German stations, and earthquake information from various international geological services, such as the United States Geological Survey,” said Markus Dohmann, BGR geophysicist. “The database forms the basis for our scientific work in the field of seismology and provides information on current earthquake alerts in Germany, Europe and across the globe. The Earthquake Monitor System (ERMOS) displays this earthquake information in a Web application in the form of epicenter maps.”
The BGR had been running the Ingres database for more than 20 years, Dohmann said, and the institute was happy with its performance. A highly reliable, stable database is crucial to the BGR. Its contractual obligation to the CTBTO includes a minimum of 98 percent data availability and uptime, and Dohmann said Ingres worked just fine in that role. When Ingres released its database as open-source software in 2004, Dohmann started thinking about the potential benefits of a switch to open source, not only for BGR’s applications, but also for its entire infrastructure.
Dohmann was already familiar with the concept of open-source software since the BGR was using several open-source tools, such as GMT, a free, open-source collection of 60 Unix tools used to manipulate (x,y) and (x,y,z) data sets and produce Encapsulated PostScript File illustrations, created by the University of Hawaii. The BGR also uses MapServer, an open-source development environment for building spatially enabled Internet applications, created by developers at the University of Minnesota, and the widely available GNU toolset. Because of his familiarity with these open-source licensed tools, Dohmann understood the inner workings of the open-source community, and he knew that open-source software was secure and robust enough to do the critical work of around-the-clock seismic activity monitoring.
So when BGR hardware was coming to the end of its lifecycle and needed to be replaced, Dohmann decided that it would be a great idea to move from a proprietary infrastructure to one based on open-source software, and not just for the obvious money-saving reasons. “An open-source solution offers advantages like flexible installation without being tied down to licenses,” Dohmann said, as well as the ability to commoditize the infrastructure on less-expensive x86 hardware. After comparing the Ingres open-source database with several other products, including Oracle’s well-known proprietary database, Dohmann was persuaded. “They all involved higher conversion costs and greater administrative complexity, especially since we needed to convert every single application that accessed the database,” he said.
The result: In 2007, BGR undertook a massive migration from a Sun SPARC infrastructure to Linux and Solaris x86 on commodity hardware. Additionally, BGR moved from Ingres’s proprietary database to its open-source product. Because BRG was able to keep the same database, the migration was made easier, but it was still a challenge, Dohmann said. Some problems arose when he and his team had to “adapt around 100 programs in an extremely limited time period.” The team had to work around the clock, completing the switchover of the entire database system and its respective applications in a single day to ensure the briefest possible downtime for the seismology data center.
Once the transition was complete, Dohmann was happy with the results. “We not only benefit from the lower cost of ownership attributed to the open-source business model, but from the strong community surrounding open source as well. The rapid feedback received from the community to queries on specialist topics is a major plus. In our sector in particular, the reliability and availability of data are decisive criteria.”
Now that Dohmann has weathered the challenges of a successful migration to an open-source infrastructure, he said it’s beneficial to have a good understanding of Linux before making the switch. “Familiarize yourself with the new operating system and test the installations…on the new system,” before committing to a complete overhaul, Dohmann offers to other research facilities that may be considering a migration on the scale of the BGR’s transition. And when moving from Sun hardware to commodity hardware architecture, Dohmann wryly recommended, “Transfer all your data in ASCII format.”