Hello Wei, If the 90th value of, for example, 2ms, means that 90% of the requests experience a latency of up to 2ms. The same applies for 95th percentile.The target latency you want to achieve depend on your frontend application, but it’s typically 5-10ms.
Regarding the throughput, you first need to run the workload several times and every time gradually increase the throughput target (rps) to figure out what is what is the maximum throughput that doesn’t violate the QoS. After that you can do your final run. If you are collocating another workload with memcached, make sure that the other workload is in its steady state while you are tuning memcached. I don’t remember the exact throughput we achieved, but I believe it should be around 60-70K rps per core on Xeon-based machines. This, of course, depends on your hardware. The scalability of memcached is known not to be great, so the per-core throughput is expected to drop as you scale it. Regards, Djordje ________________________________________ From: Wei Kuang [[email protected]] Sent: Sunday, July 06, 2014 4:04 PM To: [email protected] Subject: questions about the cloudsuite-data caching Hi, I am doing co-run experiment, so basically I have to run cloudsuite and another program together on a machine. And they shared some resources, such as cache and memory bandwidth. Currently, I need to look at the performance degradation of data caching when it co-run with other programs. Now the data caching has been set up on a core2duo machine. I use taskset so that, these two program have its own dedicated core. My question is what is a normal output of the client-side report, say, the rps, I noticed some times rps goes up to 50k, some time it only 1-3k, never see it become a stable state. And Could you explain more about the 90th 95th, I know its about QOS and the number is in milliseconds. Still I am not sure what does that number mean.
