Memcached Benchmark

The following describe the details of the Memcached benchmark making it reproducible. Let us know if you find anything is missing.

Latest Results (Feb 19)

CPU	Seastar Memcached with DPDK	Stock Memcached (multi process)	Stock memcached (multi threaded)
2	553,175	350,844	321,287
4	1,021,918	615,270	573,149
6	1,703,790	857,428	709,502
8	2,149,162	1,102,417	741,356
10	2,629,885	1,335,069	608,014
12	2,870,919	1,528,598	608,968
14	3,217,044	1,726,642	440,658
16	3,460,167	1,887,060	603,479
18	4,049,397	2,167,573	902,192
20	4,426,457	2,281,064	1,128,469

Test bed:

• Server 1: Memcache server
• Server 2: Memcache Client - memaslap

Software

Server 1 (Stock Memcached) Setup:

• Memcached version 1.4.17
• One, single threaded, Memcached process per CPU

Server 1 (Seastar Memcached with DPDK) Setup:

1. Fetch dpdk from upstream (support for i40e is not sufficient in 1.8.0)
2. update config/common_linuxapp
3. update CONFIG_RTE_MBUF_REFCNT to 'n'
4. update CONFIG_RTE_MAX_MEMSEG=4096
5. follow instructions from Seastar readme on DPDK installation for 1.8.0

• hugepages define 2048,2048 pages
• compile seastar

6. sudo build/release/apps/memcached/memcached --network-stack native --dpdk-pmd --dhcp 0 --host-ipv4-addr $seastar_ip --netmask-ipv4-addr 255.255.255.0 --collectd 0 --smp $cpu

Server 2 (memaslap) Setup

• memaslap from libmemcached-1.0.18
• Disable irqbalance
• Fix the irq smp_affinity of the 40Gb card to invoke each interrupt on a single cpu

for $cpu < 6 
for ((i = 0; i < 12; ++i)); do taskset -c $i memaslap -s $seastar_ip:11211 -t 60s -T 1 -c 60 -X 64 & done

for $cpu >= 6 
for ((i = 0; i < 52; ++i)); do taskset -c $i memaslap -s $seastar_ip:11211 -t 60s -T 1 -c 60 -X 64 & done

• verify there are no misses in each test - restart memcached for each test

Hardware

Same as HTTPD Test