示例:
如目前有 10.39.3.25--29 集群, 选其中3个25、26、27 做为manager节点,用于管理swarm集群和实现高可用。
# docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS
dga3oelektv4tbofub2ii9d36 cephnode5 Ready Active
j0hmbmvn9pwnpr1n9zm20j67k * cephnode3 Ready Active Reachable
k7pb8msn85c6xzflbe4r57itd cephnode1 Ready Active Reachable
mmlszdi5lcr0zt2nk44pcjvya cephnode4 Ready Active
t9f91au60k3cgf406cqe1pn2t cephnode2 Ready Active Leader
2个manager是无法实现高可用的,主节点异常后,备用节点运行命令将报错如下:
#docker node ls
Error response from daemon: rpc error: code = 2 desc = The swarm does not have a leader. It's possible that too few managers are online. Make sure more than half of the managers are online.