Hitoshi Mitake 454865bd67 tools: a new tool for benchmarking storage backends
Current etcd repository has a test for benchmarking a storage backend
in storage/kvstore_bench_test.go. However, it is hard to test various
parameters (e.g. batch interval, a number of keys, etc) with the test.

This commit adds a new benchmarking subcommand "storage" to
tools/benchmark. It will encourage analysis of storage backends with
various parameter and complex workloads.

Exmaple usage:
$ ./benchmark storage put
total: 9.894173792s
average: 9.894173ms
minimum latency: 6.596991ms
maximum latency: 29.455695ms
2016-01-01 15:18:54 +09:00
..