We argue for a simple change to Byzantine Fault Tolerant state machine
replication libraries in order to provide high throughput. Traditional
state machine replication based Byzantine fault tolerant (BFT)
techniques provide high availability and security but fail to provide
high throughput. This limitation stems from the fundamental assumption
of generalized state machine replication techniques that all replicas
execute requests sequentially in the same total order to ensure
consistency across replicas. We propose a high throughput Byzantine
fault tolerant architecture that uses application-specific information
to identify and concurrently execute independent requests. Our
architecture thus provides a general way to exploit application
parallelism in order to provide high throughput without compromising
correctness. Although this approach is extremely simple, it yields
dramatic practical benefits. When sufficient application concurrency
and hardware resources exist, CBASE, our system prototype, provides
orders of magnitude improvements in throughput over BASE, a
traditional BFT architecture. CBASE-FS, a Byzantine fault tolerant
file system that uses CBASE, achieves twice the throughput of BASE-FS
for the IOZone micro-benchmarks even in a configuration with modest
available hardware parallelism.