We (Outbrain) are using glu 4.7.2 and we need to change the zookeeper cluster glu is using.
I wanted to know if there's a specific way you recommend doing this?
Just change configuration for all agents and restart? What will happen then to the state of the services that were registered with the old Zookeeper cluster?
Also - I've found the configuration file for changing the agent's Zookeeper hosts - agent-server/data/config/agent.properties but I can't seem to find the same configuration for the console. Where can I find that?
I am not entirely sure of the exact steps to follow if you are going to migrate from an old cluster to a new one in terms of ZooKeeper and you should probably check with ZooKeeper docs if they have some recommendations. Also it depends on how much/if you want any downtime or not. For no downtime, if you can have the 2 clusters running at the same time and talking to each other, I think you can probably follow those steps (untested, it should work in "theory", you may want to test this steps separately):
* change console to have old cluster + new cluster for each fabric => at this time the console will know about the new ZK cluster as well as the old one. All agents are talking only to the old one.
* change 1 agent to know only about the new cluster. restart this agent. The console should pick it up.
* provided previous step worked, do this with all agents => at the end of this step all agents will be talking only to new cluster.
* change console to have new cluster only
* change new ZK cluster to know only about the new ZK cluster.
* shut down old ZK cluster.
Note that the zookeeper configuration for the console is not stored in a config file and you can edit it by going to Admin/Create Add Fabric and changing the ZkConnect String for your fabric(s). No need to restart the console.