
70 High Performance Parallel I/O
6.2.4 The Curse of the Burst: Economic Thinking behind
Burst Buffers
HPC I/O currently is dominated by extreme bursts of data, not only in
the checkpoint workload but also in analysis workloads. Since I/O time is non-
productive time in general, the goal is to make I/O time minimal. As machine
memory sizes get bigger, from 1 PB of memory to exascale-class machines
with 50–100 PB of memory, the size of bursts is becoming enormous. Further,
given the shrinking job mean time to interrupt (JMTTI), for the checkpoint
use case, the time for the I/O burst is shrinking. Figure 6.2 shows the effect
of the ratio of JMMT over chec ...