I agree – do not aim for a mixed version as normal. Mixed versions are fine during an upgrade process, but the goal is to complete the upgrade as soon as possible.
As for other parts of your plan, the Kafka Connector is a “sink-only,” which means that it can only insert into Cassandra. It doesn’t go the other way. I usually suggest that if the data is needed in two (or more) places, that the application write to a queue. Then, let the queue feed all the downstream destinations. Sean Durity – Staff Systems Engineer, Cassandra From: Christopher Bradford <bradfor...@gmail.com> Sent: Thursday, April 16, 2020 1:13 AM To: user@cassandra.apache.org Subject: [EXTERNAL] Re: Multi DC replication between different Cassandra versions It’s worth noting there can be issues with streaming between different versions of C*. Note this excerpt from https://thelastpickle.com/blog/2019/02/26/data-center-switch.html [thelastpickle.com]<https://urldefense.com/v3/__https:/thelastpickle.com/blog/2019/02/26/data-center-switch.html__;!!M-nmYVHPHQ!cPTqPpkLv1YvwMse4ApY-5I_2FOybuD6fqw3uE0fYHJnJAmMKgcpysJMQInae06wWpM26pA$> Note that with an upgrade it’s important to keep in mind that streaming in a cluster running mixed versions of Casandra is not recommended Emphasis mine. With the approach you’re suggesting streaming would be involved both during bootstrap and repair. Would it be possible to upgrade to a more recent release prior to pursuing this course of action? On Thu, Apr 16, 2020 at 1:02 AM Erick Ramirez <erick.rami...@datastax.com<mailto:erick.rami...@datastax.com>> wrote: I don't mean any disrespect but let me offer you a friendly advice -- don't do it to yourself. I think you would have a very hard time finding someone who would recommend implementing a solution that involves mixed versions. If you run into issues, it would be hell trying to unscramble that egg. On top of that, Cassandra 3.0.9 is an ancient version released 4 years ago (September 2016). There are several pages of fixes deployed since then. So in the nicest possible way, what you're planning to do is not a good idea. I personally wouldn't do it. Cheers! -- Christopher Bradford ________________________________ The information in this Internet Email is confidential and may be legally privileged. It is intended solely for the addressee. Access to this Email by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. When addressed to our clients any opinions or advice contained in this Email are subject to the terms and conditions expressed in any applicable governing The Home Depot terms of business or client engagement letter. The Home Depot disclaims all responsibility and liability for the accuracy and content of this attachment and for any damages or losses arising from any inaccuracies, errors, viruses, e.g., worms, trojan horses, etc., or other items of a destructive nature, which may be contained in this attachment and shall not be liable for direct, indirect, consequential or special damages in connection with this e-mail message or its attachment.
