优化，调整IO优先级

ionice -c 1 -n 1 -p 2728858
http://linux.51yip.com/search/ionice
https://www.cnblogs.com/lizhewei/p/13036463.html

参数优化

–heartbeat-interval ‘100’ 改为 500 –election-timeout ‘1000’ 改为 5000

测试1

etcdctl --cacert ca.crt --cert healthcheck-client.crt --key healthcheck-client.key check perf
60 / 60 Booooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo! 100.00%1m0s
PASS: Throughput is 150 writes/s
PASS: Slowest request took 0.172822s
PASS: Stddev is 0.008926s
PASS

# etcdctl --endpoints https://10.100.0.100:2379 --cacert=/etc/etcd/pki/ca.crt --cert=/etc/etcd/pki/client.crt --key=/etc/etcd/pki/client.key  check perf
 60 / 60 Booooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo! 100.00% 1m0s
PASS: Throughput is 150 writes/s
PASS: Slowest request took 0.092653s
PASS: Stddev is 0.006833s
PASS

测试2

关于 etcd 对磁盘的性能要求，以及MySQL高可用部署的节点要求内容如下：

etcd磁盘性能要求：

etcd是磁盘IO敏感性的键值数据库，对磁盘性能的要求：99%的 fdatasync 请求延迟小于 10ms (即10000us)

相关材料：磁盘要求：https://etcd.io/docs/v3.4.0/op-guide/hardware/#disks 测试工具：https://github.com/axboe/fio 测试方案：https://www.ibm.com/cloud/blog/using-fio-to-tell-whether-your-storage-is-fast-enough-for-etcd

获取工具包： http://mirror.centos.org/centos/7/os/x86_64/Packages/fio-3.7-2.el7.x86_64.rpm http://mirror.centos.org/altarch/7/os/armhfp/Packages/fio-3.7-2.el7.armv7hl.rpm

安装工具： yum -y install ./fio-3.7-2.el7.x86_64.rpm

测试性能： cd 磁盘挂载的数据目录 mkdir test-data fio –rw=write –ioengine=sync –fdatasync=1 –directory=test-data –size=22m –bs=2300 –name=mytest

结果分析：测试结果中关注 fdatasync 指标中 99th ，要求小于 10000 （usec）

参数优化

--heartbeat-interval '100'   改为 500
--election-timeout '1000'   改为 5000

但是修改了这2个参数后，集群运行稳定，命令执行比较流畅，没有helm/kubectl执行失败

赵文宇: helm/kubectl 执行返回时间 0.2 秒和 2秒，在人的感知上差别不大