RHEL5.8通过EPEL源安装 salt-minion，启动的时候日志报错：[WARNING ] You have a version of ZMQ less than ZMQ 3.2! There are known connection keep-alive issues with ZMQ < 3.2 which may result in loss of contact with minions. Please upgrade your ZMQ!

    原因是salt-master版本用的是ZMQ3，salt-miniton用的还是ZMQ2.2，他们之间通讯keep-alive不可用导致的，方法就是升级ZMQ版本>3.2,网上找了一下解决方法，果然都是一个地方复制黏贴，还麻烦无比。其实比较容易的解决方法就是先下载两个文件：

http://copr-be.cloud.fedoraproject.org/results/saltstack/zeromq4/epel-5-x86_64/zeromq-4.0.4-2.el5/zeromq-4.0.4-2.el5.x86_64.rpm

和

http://copr-be.cloud.fedoraproject.org/results/saltstack/zeromq4/epel-5-x86_64/python-zmq-14.3.1-3.el5/python26-zmq-14.3.1-3.el5.x86_64.rpm

执行rpm -Uvh python26-zmq-14.3.1-3.el5.x86_64.rpm zeromq-4.0.4-2.el5.x86_64.rpm

重启salt-minion：

/etc/init.d/salt-minion restart

相关文章：

https://github.com/saltstack/salt/issues/4440

http://copr-be.cloud.fedoraproject.org/results/saltstack/zeromq4/epel-5-x86_64/

Centos 5.x RHEL 5.x 安装salt升级Zmq2.x 到Zmq4.x