Strong +1. Much like having repair scheduling built in to the ecosystem, this feels like table stakes for having a self-contained, usable distributed database.
On Wed, Dec 18, 2024, at 6:11 PM, Dinesh Joshi wrote: > Hi Jordan, > > Thank you for starting this thread. This is a great idea. From an ecosystem > perspective this is absolutely critical. I'm a big +1 on working towards > building this into Cassandra and the surrounding ecosystem. This would a step > in the right direction to derisk upgrades. > > Dinesh > > On Wed, Dec 18, 2024 at 3:01 PM Jordan West <jw...@apache.org> wrote: >> In a recent discussion on the pains of upgrading one topic that came up is a >> feature that Riak had called Capabilities [1]. A major pain with upgrades is >> that each node independently decides when to start using new or modified >> functionality. Even when we put this behind a config (like storage >> compatibility mode) each node immediately enables the feature when the >> config is changed and the node is restarted. This causes various types of >> upgrade pain such as failed streams and schema disagreement. A recent >> example of this is CASSANRA-20118 [2]. In some cases operators can prevent >> this from happening through careful coordination (e.g. ensuring upgrade >> sstables only runs after the whole cluster is upgraded) but typically >> requires custom code in whatever control plane the operator is using. A >> capabilities framework would distribute the state of what features each node >> has (and their status e.g. enabled or not) so that the cluster can choose to >> opt in to new features once the whole cluster has them available. From >> experience, having this in Riak made upgrades a significantly less risky >> process and also paved a path towards repeatable downgrades. I think >> Cassandra would benefit from it as well. >> >> Further, other tools like analytics could benefit from having this >> information since currently it's up to the operator to manually determine >> the state of the cluster in some cases. >> >> I am considering drafting a CEP proposal for this feature but wanted to take >> the general temperature of the community and get some early thoughts while >> working on the draft. >> >> Looking forward to hearing y'alls thoughts, >> Jordan >> >> [1] >> https://github.com/basho/riak_core/blob/25d9a6fa917eb8a2e95795d64eb88d7ad384ed88/src/riak_core_capability.erl#L23-L72 >> >> [2] https://issues.apache.org/jira/browse/CASSANDRA-20118
