Another hit from the DevOps request backlog. I'm glad this has
finally turned into something formal. This will make CI/CD much easier. One
thing I hope this fosters more of is the sharing of configs. For example,
"here are my recommended storage settings for EBS."
The CEP aborts on any duplicate key. For the people doing GitOps, there
will be a need for layering a read-only baseline `cassandra.yaml` with
environment-specific or secret files. This is exactly the way Argo CD/Helm
handles value precedence. This is typical in cloud native environments. I
propose a modification that allows an *opt-in* policy switch:
duplicate_key_policy: { ABORT (default) | LAST_WINS | WARN }
* ABORT – current behaviour, startup fails on duplicates.
* WARN – duplicates allowed, last key wins, but every override is logged.
* LAST_WINS – same as WARN, but without log
On Mon, Jul 21, 2025 at 7:01 AM Josh McKenzie <jmcken...@apache.org> wrote:
> I suppose the only concern would be maintaining this version in alignment
> with what's going into the main cassandra.yaml as part of the regular
> development.
>
> Seems like it'd be relatively easy to script something that'll generate
> modularized config files based on the reference cassandra.yaml by
> classifying different parameters based on file grouping. Not to scope creep
> or add on to the CEP or anything, just thinking out loud; as follow up work
> it could be useful.
>
> From a technical perspective having a bi-directional sync that'd just dump
> things into a "overflow" file from monolithic -> modular, and tacking on at
> the end of cassandra.yaml under an overflow section for things not
> classified in the script from modular -> monolithic config shouldn't be too
> complex. If that proved stable, integrating that into the build process and
> even adding a checkstyle job target warning on non-classified configuration
> parameters could tighten the whole thing up and give us a minimally
> invasive way to support both through a transition.
>
> On Mon, Jul 21, 2025, at 9:41 AM, Johnny Miller wrote:
>
> I have added the section "Reference Example Configuration" - will see what
> the feedback on this is. I suppose the only concern would be maintaining
> this version in alignment with what's going into the main cassandra.yaml as
> part of the regular development.
>
> On Mon, 21 Jul 2025 at 15:24, Josh McKenzie <jmcken...@apache.org> wrote:
>
>
> That sounds useful to me.
>
> I'd like to see us move to "modularized by default"; our current config
> being 2839 lines of .yaml
> <https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml> is a
> bad experience for both new and old users. Starting with examples of the
> new paradigm and then refactoring config out over time for the default
> config is a path forward I'd support.
>
> On Mon, Jul 21, 2025, at 9:18 AM, Johnny Miller wrote:
>
> One feature I was thinking of adding to the CEP was to have an example
> yaml config setup using the includes with the config grouped logically so
> people have a reference example in the conf? Would this be a good idea?
>
> On Fri, 18 Jul 2025 at 19:57, Johnny Miller <johnny.p.mil...@gmail.com>
> wrote:
>
> Hello 👋
>
> We would like to propose CEP-51: Support Include Semantics for
> cassandra.yaml for adoption by the community:
>
> https://cwiki.apache.org/confluence/display/CASSANDRA/CEP-51+Support+Include+Semantics+for+cassandra.yaml
>
> This CEP proposes adding completely optional include directives to
> Cassandra's configuration system, allowing users who need it to split their
> cassandra.yaml into multiple files for better security, organization, and
> deployment flexibility. No changes are made to the default cassandra.yaml,
> and this feature is entirely opt-in.
> The proposed include directives (include, include_if_exists, and
> include_dir) enable organizations to:
>
> - Apply the principle of least privilege by separating sensitive
> security configurations into files with restricted permissions
> - Better organize large configuration files by logical subsystems
> - Simplify configuration management in environments where different
> teams manage different aspects of the cluster
> - Follow established patterns already present in PostgreSQL, MySQL,
> Redis, NGINX, and other widely-used systems
>
> Key design principles:
>
> - Zero impact on users who don't use the feature
> - No recursive includes (only the main cassandra.yaml can contain
> include directives)
> - No duplicate configuration keys allowed (each setting must appear in
> exactly one file)
> - Clear error messages for troubleshooting
>
> This enhancement addresses real operational challenges faced by
> organisations with strict security requirements or complex deployment
> needs, while maintaining complete backward compatibility and requiring no
> changes to existing deployments.
>
> Thanks in advance for your time and feedback. Please keep the discussion
> on this mailing list thread.
>
> Regards,
>
> Johnny
>
>
>
>
