I have a question about some of the details of OpsCenter's Column Family in Cassandra.
We are working on building a recyclable demo of Cassandra in Amazon using custom AMIs and EBS volumes. I have a question about whether OpsCenter can be installed permanently into the AMIs or whether we would have to reinstall it each time we respawn the cluster (with different IPs) using the AMIs.
Say I have 5 Amazon EC2 nodes running Brisk 1.0 and the first node has OpsCenter installed on it. The Cassandra database (including the OpsCenter CF) is not on the local ephemeral drives, but rather on EBS volumes that were connected to the 5 nodes.
Then I permanently store each node as an AMI that I can relaunch later to respawn the cluster. So, typically we will terminate the 5 nodes, but keep the databases intact on the 5 EBS volumes. When we want to show a demo of Cassandra, we'll launch 5 new EC2 nodes (from 5 individualized AMIs) and reconnect the 5 EBS volumes to the new EC2 nodes. Note that the IP addresses for the new 5 nodes will be different than the old five nodes. We have some puppet scripts that will update the YAML file and other configuration files on the fresh 5 nodes before starting Cassandra.
Casssandra restarts fine and reconnects to all of the databases on the EBS drive. But my question is regarding OpsCenter.
When OpsCenter is first installed, it detects the Amazon Private IPs for all 5 nodes and installs Agents on them and creates a special OpsCenter Column Family to store metrics.
My question is: In our recyclable demo, can we install OpsCenter on the first node and the agents on the rest of the nodes BEFORE saving our permanent AMIs? Are the private IPs for the cluster stored that OpsCenter Column family so that it would get confused/break if the cluster started up with different IPs?
Currently, we don't have OpsCenter on the AMIs. Instead every time we launch a fresh 5 nodes, we reinstall OpsCenter and the Agents.
We would like to automate this and make the respawn process faster by just baking OpsCenter into the AMI so even if we relaunch the cluster with new private IPs, we don't have to reinstall OpsCenter.
Is it possible to do what we want to do?