Clear Sailing for Allinea DDT at 700,000+ MPI Tasks on Blue Waters

Mon April 8, 2013

Tough requirements and a tight timeline called for tools ready to deploy at the largest scales

Blue Waters supercomputerThe Blue Waters supercomputer is now in production, setting a new scalability record for Allinea DDT, the popular debugger installed on over 45 of the world’s top 100 supercomputers, and which is now in routine use by computational scientists there at scale.

Blue Waters, a Cray supercomputer commissioned by the University of Illinois’s National Center for Science Applications (NCSA) and the National Science Foundation (NSF), is the world’s fastest supercomputer on a university campus with a theoretical capacity of 11.62 petaflops.

Blue Waters will be entirely available for open science. Projects will span the spectrum from the minute to the cosmic, everything from examining the structure of viruses to predicting the weather in outer space.

While getting the machine up to speed, the Blue Waters team ran their own demanding acceptance trials with Allinea DDT debugging more than 700,000 MPI processes simultaneously.

“Having Allinea DDT in the hands of users at this scale whenever the need arises and at any scale – with its lightning fast performance and easy to use interface – is a critical part of getting the scientific applications to super-petascale,” says David Lecomber, COO and founder of Allinea.

The implementation of the Blue Waters system had a tough timeline – and having a debugger ready to deploy at large scales was critical to meeting the schedule.

“We knew our tool was more than ready,” says Lecomber. “We wanted the NCSA to take Allinea DDT to the extreme and see it first-hand, as real users. They came back with the news that it was 30x faster than they specified in performing common debugging tasks—without any extra tuning.”

System engineers at Cray knew they could count on Allinea because of its track record at major labs such as the Oak Ridge Leadership Computing Facility, home of Titan, the world’s fastest supercomputer.

cray logo registered tagline 294c“The exacting tools requirements of this project needed to be entrusted to a partner with the ability to deliver,” said Peg Williams, Cray’s senior vice president of high performance computing systems. “Allinea has proven a great partner for multiple Cray customer installations and was ideal for the Blue Waters system. Their debugging tool is known for its scalable performance and scalable user interface, which are matched to the requirements of NCSA.”

NCSA - Blue Waters"We set tough targets, and Allinea succeeded in providing a highly capable and usable debugger at the full scale of the system. Allinea also showed flexibility in licensing so we can ramp up and down and not just pay only for the largest possible case.  Now our users can find and fix problems up to full-machine size," said NCSA's Dr. William Kramer, Project Director for Blue Waters. "Another great thing is Allinea DDT is usable on both our XE6 and XK7 nodes. Allinea has already delivered training to our users and staff to help them to understand the best practices for debugging HPC applications."