I did a small poc for this *(similar rpc_address for both data centers) . *My observations:
1. rpc_address is used by a client( datastax java driver) in my case to connect to cassandra nodes. 2. Driver is keeping a list of contact points which it is updating using system.peers table 3. Having two entries for the same rpc_address sometimes results in one of the contact points being overridden by a host from another DC. 4. After updates, your cluster metadata may contain contact points from different DC which is not what we wanted and it results in traffic failure as the driver is not willing to contact hosts of other DC. 5. Lessons learnt : Don't keep similar rpc_address on two data centers. Regards Manish On Thu, Jun 25, 2020 at 6:29 AM Erick Ramirez <erick.rami...@datastax.com> wrote: > In a network one can assign valid private IP. Private IPs can conflict if >> we do not put any restriction on private IP. >> > > Yes, you're right and I was aware of that (not realising that your > question was more around what I would consider multi-region comms). My > disconnect now is around the motivation for doing it. > > Yes, it will work since C* will communicate over the broadcast address > across regions. But I personally wouldn't go down this path for the > operational complexity it adds though YMMV. Cheers! >
