The SSD based system running the same workload had plenty of IOPS left over and could also run compaction operations under full load without affecting response times. The overall throughput of the 12-instance SSD based system was CPU limited to about 20% less than the existing system, but with much lower mean and 99th percentile latency. This sizing exercise indicated that we could replace the 48 m2.4xlarge and 36 m2.xlarge with 15 hi1.4xlarge to get the same throughput, but with much lower latency.
Tons of details and data about the benchmarks Netflix ran against the new high I/O SSD-backed EC2 instances. Results are even more impressive than the IOPS numbers in Werner Vogel’s High performance I/O instances for EC2.
Original title and link: Benchmarking High Performance I/O With SSD for Cassandra on AWS ( ©myNoSQL)