The below warning message maybe encountered while your start salt-minion service in CentOS system after you installed the salt-minion.
"[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!"
How to resolve this problem? what reason caused to this warning message? In this post you will see the reason and how to figure it out.
The Mainly reason is that salt-miniton utilizes ZMQ 2.2 version and salt-master use ZMQ 3, so this will caused communication problem between salt-master and salt-minion. so the resolved ways is that upgrading ZMQ2.x to ZMQ 3.x or ZMQ 4.x, in the below, you’ll see the upgrading steps from ZMQ2.x to ZMQ 4.x.
CentOS Upgrade ZMQ 2.x To ZMQ 4.x
Step1# Download the below packages, issue the following command:
$sudo wget 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 $sudo wget 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
Step2# upgrade those two package using the following command:
$sudo rpm -Uvh python26-zmq-14.3.1-3.el5.x86_64.rpm $sudo rpm -Uvh zeromq-4.0.4-2.el5.x86_64.rpm
Step3# restart salt-minion service, type:
$sudo /etc/init.d/salt-minion restart