docs/ops/pikaVsSSDB.md
#pika与ssdb性能对比
相同配置服务端、客户机各1台：
CPU: 24 Cores, Intel(R) Xeon(R) CPU E5-2630 v2 @ 2.60GHz
MEM: 198319652 kB
OS: CentOS release 6.2 (Final)
NETWORK CARD: Intel Corporation I350 Gigabit Network Connection
set和get
使用ssdb和pika默认配置(pika配16个worker)，客户机执行 ./redis-benchmark -h ... -p ... -n 1000000000 -t set,get -r 10000000000 -c 120 -d 200，通过set和get接口分别对ssdb和pika进行10亿次写入+10亿次读取
ssdb
1000000000 requests completed in 25098.81 seconds
0.52% <= 1 milliseconds
96.39% <= 2 milliseconds
97.10% <= 3 milliseconds
97.34% <= 4 milliseconds
97.57% <= 5 milliseconds
…
98.87% <= 38 milliseconds
...
99.99% <= 137 milliseconds
100.00% <= 215 milliseconds
...
100.00% <= 375 milliseconds
39842.53 requests per second
pika
1000000000 requests completed in 11890.80 seconds
18.09% <= 1 milliseconds
93.32% <= 2 milliseconds
99.71% <= 3 milliseconds
99.86% <= 4 milliseconds
99.92% <= 5 milliseconds
99.94% <= 6 milliseconds
99.96% <= 7 milliseconds
99.97% <= 8 milliseconds
99.97% <= 9 milliseconds
99.98% <= 10 milliseconds
99.98% <= 11 milliseconds
99.99% <= 12 milliseconds
...
100.00% <= 19 milliseconds
...
100.00% <= 137 milliseconds
84098.66 requests per second
ssdb
1000000000 requests completed in 12744.41 seconds
7.32% <= 1 milliseconds
96.08% <= 2 milliseconds
99.49% <= 3 milliseconds
99.97% <= 4 milliseconds
99.99% <= 5 milliseconds
100.00% <= 6 millisecondsj
...
100.00% <= 229 milliseconds
78465.77 requests per second
pika
1000000000 requests completed in 9063.05 seconds
84.97% <= 1 milliseconds
99.76% <= 2 milliseconds
99.99% <= 3 milliseconds
100.00% <= 4 milliseconds
...
100.00% <= 33 milliseconds
110338.10 requests per second
由于pika的设计支持多线程的读写（ssdb仅支持1个线程写，多个线程读），在本测试环境中，pika写性能是ssdb的2.1倍（qps：84098 vs 39842），读性能是ssdb的1.4倍（qps：110338 vs 78465）
ssdb 写延迟分布 0.52%在1ms以内, 97.10%在3ms以内, 而pika 的写延迟分布18.32%在1ms以内, 99.71%在3ms以内. 说明 pika 的写延迟在写入量相同的情况下（10亿）下明显优于ssdb
ssdb 读延迟分布7.32%在1ms以内, 99.49%在3ms以内, 而pika 的84.97%在1ms以内, 99.99%在3ms以内. 说明 pika 的读延迟在读取量相同的情况（10亿）下优于ssdb
所以在本测试环境中，pika 各个方面的性能都优于ssdb