I am using operator version:1.3 and application version: 3.11.6. I am using 2 data centers with same number of nodes.Will cass-operator supports disaster recovery. If supports how to achieve it?
Could you clarify the support you're looking for? For losing k8s workers? For losing volumes? Something else?
Your question is too open-ended for us to be able to provide a meaningful answer but I'll try my best to respond based on some assumptions.
The concept of disaster recovery (DR) is an old paradigm that is rooted in near-obsolete practices when an organisation's infrastructure was geographically distributed to just 2 or 3 locations. A remote DC classified as a DR site would get activated in the event of a catastrophic failure at the primary site. These days, most organisation cannot tolerate interruptions to their business operations and so have their systems running active-active all the time.
A multi-DC cluster in Cassandra operates in active-active fashion -- there is no primary, there is no secondary. All DCs receive writes from the application(s) in real-time. If DC1 is unavailable (for whatever reason), the remaining DCs continue to operate and the traffic gets diverted to the operational DCs.
Specifically with the cass-operator, when a node goes down, the operator will attempt to automatically recover the statefulsets (STS) provided the outage isn't due to a failure in the underlying infrastructure (e.g. physical host servers going down). Jim Dickinson will correct me if I'm mistaken but there is a limitation with Kubernetes at this point where multi-region deployments isn't a supported feature so clusters can only be deployed to a single-region right now. Cheers!
Thanks @Erick Ramirez. I just write the data into the Node of DC1. I just deleted the DC1 and tried to connect to DC2 , I can get the keyspaces and tables. But not the data . When I try to retrieve the data, It is giving error like Host not found. But from your explaination, it should retrieve data when DC1 goes down. How can I get data when 1 Dc goes down. Can you please explain.
As I thought, your question wasn't really about the cass-operator. This is really more about how replication works. Will you please post the schema for your keyspace? I just need to look at the line which has the replication settings like this:
CREATE KEYSPACE ks_name WITH REPLICATION = ...
Cheers!
This is the one I used:
CREATE KEYSPACE mykeyspace WITH replication = {'class': 'NetworkTopologyStrategy', 'dc1': '3', 'dc2': '3'} AND durable_writes = true
6 People are following this question.
