diff --git a/README.md b/README.md index 4514c4edf..a495b97f6 100644 --- a/README.md +++ b/README.md @@ -497,6 +497,19 @@ If you are using SSL for server to server communication, you must use it on all - [mattn/etcd-vim](https://github.com/mattn/etcd-vim) - SET and GET keys from inside vim - [mattn/etcdenv](https://github.com/mattn/etcdenv) - "env" shebang with etcd integration +## FAQ + +### What size cluster should I use? + +Every command the client sends to the master is broadcast it to all of the followers. +But, the command is not be committed until the majority of the cluster machines receive that command. + +Because of this majority voting property the ideal cluster should be kept small to keep speed up and be made up of an odd number of machines. + +Odd numbers are good because if you have 8 machines the majority will be 5 and if you have 9 machines the majority with be 5. +The result is that an 8 machine cluster can tolerate 3 machine failures and a 9 machine cluster can tolerate 4 nodes failures. +And in the best case when all 9 machines are responding the cluster will perform at the speed of the fastest 5 nodes. + ## Project Details ### Versioning