If we support both formats for a time, I just would want to make absolutely sure that it will read only one or the other so there's no uncertainty about the server configuration. Perhaps to avoid unforeseen migration problems, we only read the old format if a specific flag is set? So with version 5, we only read the new format by default. So if you only have the old format and you try to start 5.0, it will fail with a log message about a JVM option to be used ("READ_CASSANDRA_YAML" or something). So if you enable that, you *only* read the old config. It would be one or the other so you don't have weird dilemmas of which one to choose.
> On Feb 23, 2022, at 11:30 AM, Caleb Rackliffe <calebrackli...@gmail.com> > wrote: > > > Continuing to parse the old format for some time seems unavoidable, and > allowing dot-separated options in the old format seems reasonable. > > There will certainly be some interesting problems when we move into > implementation space with this. One approach might be to implement a clean > object model that corresponds to the new format, work out how it's > parsed/populated from the file, and then have some kind of converter from the > old Config object to the new object model that allows us to provide values to > DatabaseDescriptor from only the new one (thereby avoiding any changes to the > places all over the codebase that use DD). > > On Wed, Feb 23, 2022 at 4:46 AM Bowen Song <bo...@bso.ng > <mailto:bo...@bso.ng>> wrote: > I agree with Benedict, there's legit use cases for both the flat and > structured config file format. The operator should be able to choose which > one is best suited for their own use case. It will also make the upgrade > process easier if both formats are supported by future versions of Cassandra. > > On 23/02/2022 07:52, bened...@apache.org <mailto:bened...@apache.org> wrote: >> I agree that a new configuration layout should be introduced once only, not >> incrementally. >> >> >> >> However, I disagree that we should immediately deprecate the old config file >> and refuse to parse it. We can maintain compatibility indefinitely at low >> cost, so we should do so. >> >> >> >> Users of the old format, when using new configuration options, can simply >> use dot separators to specify them. Since most settings are not required, >> this is by far the least painful upgrade process. >> >> >> >> >> >> From: Berenguer Blasi <berenguerbl...@gmail.com> >> <mailto:berenguerbl...@gmail.com> >> Date: Wednesday, 23 February 2022 at 06:53 >> To: dev@cassandra.apache.org <mailto:dev@cassandra.apache.org> >> <dev@cassandra.apache.org> <mailto:dev@cassandra.apache.org> >> Subject: Re: [DISCUSS] CASSANDRA-17292 Move cassandra.yaml toward a nested >> structure around major database concepts >> >> +1 to a non-incremental approach as well. >> >> On 23/2/22 1:27, Caleb Rackliffe wrote: >> > @Patrick I’m absolutely intending for this to be a 5.0 concern. The only >> > reason why it would have any bearing on 4.x is the case where we’re adding >> > new config that could fit into the v2 structure now and not require any >> > later changes. >> > >> >> On Feb 22, 2022, at 3:22 PM, Bernardo Sanchez >> >> <bernard...@pointclickcare.com> <mailto:bernard...@pointclickcare.com> >> >> wrote: >> >> >> >> unsubscribe >> >> >> >> -----Original Message----- >> >> From: Stefan Miklosovic <stefan.mikloso...@instaclustr.com> >> >> <mailto:stefan.mikloso...@instaclustr.com> >> >> Sent: Tuesday, February 22, 2022 3:53 PM >> >> To: dev@cassandra.apache.org <mailto:dev@cassandra.apache.org> >> >> Subject: Re: [DISCUSS] CASSANDRA-17292 Move cassandra.yaml toward a >> >> nested structure around major database concepts >> >> >> >> "EXTERNAL EMAIL" - This email originated from outside of the >> >> organization. Do not click or open attachments unless you recognize the >> >> sender and know the content is safe. If you are unsure, please contact >> >> hel...@pointclickcare.com <mailto:hel...@pointclickcare.com>. >> >> >> >> I want to add that to, however, on the other hand, we also do have dtests >> >> in Python and they need to run with old configs too. That is what >> >> Ekaterina was doing - supporting old configuration while introducing new >> >> one. If we make "a big cut" and old way of doing things would not be >> >> possible, how are we going to treat this in dtests when we will have >> >> stuff for 3.11, 4 on old configs and 5 on new configs? >> >> >> >>> On Tue, 22 Feb 2022 at 21:48, Stefan Miklosovic >> >>> <stefan.mikloso...@instaclustr.com> >> >>> <mailto:stefan.mikloso...@instaclustr.com> wrote: >> >>> >> >>> +1 to what Patrick says. >> >>> >> >>>> On Tue, 22 Feb 2022 at 21:40, Patrick McFadin <pmcfa...@gmail.com> >> >>>> <mailto:pmcfa...@gmail.com> wrote: >> >>>> >> >>>> I'm going to put up a red flag of making config file changes of this >> >>>> scale on a dot release. This should really be a 5.0 consideration. >> >>>> >> >>>> With that, I would propose a #5. 5.0 nodes will only read the new >> >>>> config files and reject old config files. If any of you went through >> >>>> the config file changes from Apache HTTPd 1.3 -> 2.0 you know how much >> >>>> of a lifesaver that can be for ops. Make it a part of the total upgrade >> >>>> to a new major version, not a radical change inside of a dot version, >> >>>> and make it a clean break. No "legacy config" laying around. That's >> >>>> just a recipe for surprises later if there are new required config >> >>>> values and somebody doesn't even realize they have some old 4.x yaml >> >>>> files laying around. >> >>>> >> >>>> Patrick >> >>>> >> >>>> On Tue, Feb 22, 2022 at 11:51 AM Tibor Répási <tibor.rep...@anzix.org> >> >>>> <mailto:tibor.rep...@anzix.org> wrote: >> >>>>> Glad to be agree on #4. That feature could be add anytime. >> >>>>> >> >>>>> If a version element is added to the YAML, then it is not necessary to >> >>>>> change the filename, thus we could end up with #3. The value of the >> >>>>> version element could default to 1 in the first phase, which does not >> >>>>> need any change for legacy format configuration. New config format >> >>>>> must include version: 2. When in some later version the support for >> >>>>> legacy configuration is removed, the default for the version element >> >>>>> could be changed to 2 or removed. >> >>>>> >> >>>>> On 22. Feb 2022, at 19:30, Caleb Rackliffe <calebrackli...@gmail.com> >> >>>>> <mailto:calebrackli...@gmail.com> wrote: >> >>>>> >> >>>>> My initial preference would be something like combining #1 and #4. We >> >>>>> could add something like a simple "version: <1|2>" element to the YAML >> >>>>> that would eliminate any possible confusion about >> >>>>> back-compat within a given file. >> >>>>> >> >>>>> Thanks for enumerating these! >> >>>>> >> >>>>> On Tue, Feb 22, 2022 at 10:42 AM Tibor Répási <tibor.rep...@anzix.org> >> >>>>> <mailto:tibor.rep...@anzix.org> wrote: >> >>>>>> Hi, >> >>>>>> >> >>>>>> I like the idea of having cassandra.yaml better structured, as an >> >>>>>> operator, my primer concern is the transition. How would we change >> >>>>>> the config structure from legacy to the new one during a rolling >> >>>>>> upgrade? My thoughts on this: >> >>>>>> >> >>>>>> 1. Legacy and new configuration is stored in different files. >> >>>>>> Cassandra will read the legacy file on startup if it exists, the new >> >>>>>> one otherwise. May raise warning on startup when legacy was used. >> >>>>>> pros: >> >>>>>> - separate files for separate formats >> >>>>>> - clean and operator controlled switch to new format >> >>>>>> - already known procedure, e.g. change from PropertyFileSnitch to >> >>>>>> GossipingPropertyFileSnitch >> >>>>>> cons: >> >>>>>> - name of the config file would change from cassandra.yaml to >> >>>>>> something else (cassandra_v2.yaml, config.yaml ???) >> >>>>>> - would need considerable work to get config to the new format >> >>>>>> - format translation not solved >> >>>>>> >> >>>>>> 2. Offline configuration converter tool may be available to convert >> >>>>>> legacy format to new one. During package upgrade, if a legacy config >> >>>>>> is found, the upgrade process should convert the config file to the >> >>>>>> new format. >> >>>>>> pros: >> >>>>>> - seamless upgrade process >> >>>>>> - tool can be tested properly before >> >>>>>> cons: >> >>>>>> - may interact badly with configuration management tools >> >>>>>> controlling the contents of cassandra.yaml >> >>>>>> - poor transparency for operators >> >>>>>> >> >>>>>> 3. Cassandra could read both formats, may warn on startup when legacy >> >>>>>> format found. >> >>>>>> pros: >> >>>>>> - no filename change >> >>>>>> - operator controlled switch to new format >> >>>>>> cons: >> >>>>>> - higher complexity at implementation and testing >> >>>>>> - format translation not solved >> >>>>>> >> >>>>>> 4. An online tool, e.g. nodetool command to export the configuration >> >>>>>> the Cassandra node is currently running with, with filtering option >> >>>>>> to suppress default settings. >> >>>>>> pros: >> >>>>>> - such a nodetool command would be useful independently from >> >>>>>> changing the config format, could be added before and support any >> >>>>>> format >> >>>>>> - the bare information is already available in >> >>>>>> system_views.settings >> >>>>>> - could be combined with #1 or #3 to support the format >> >>>>>> translation >> >>>>>> cons: ? >> >>>>>> >> >>>>>> >> >>>>>> My favourite would be #3 + #4, while I would most dislike #2. >> >>>>>> >> >>>>>> Tibor >> >>>>>> >> >>>>>> >> >>>>>> On 17. Feb 2022, at 23:13, Caleb Rackliffe <calebrackli...@gmail.com> >> >>>>>> <mailto:calebrackli...@gmail.com> wrote: >> >>>>>> >> >>>>>> Hey everyone, >> >>>>>> >> >>>>>> There has already been some Slack discussion around this, but for >> >>>>>> anyone who doesn't follow that closely, I'd like to lobby more widely >> >>>>>> for my proposal in CASSANDRA-17292 to eventually move cassandra.yaml >> >>>>>> toward a more nested structure. >> >>>>>> >> >>>>>> The proposal itself is here, and there has already been some inline >> >>>>>> discussion, but feel free to drop any feedback there, in the Jira, or >> >>>>>> here, depending on what you're most comfortable with. >> >>>>>> >> >>>>>> Given where we are in the lead-up to 4.1, I have no intention of >> >>>>>> pushing to adopt any of this for existing config in that release. >> >>>>>> However, what I think would be nice is if we could come to a rough >> >>>>>> consensus in time to inform work on new parameters, like those we're >> >>>>>> planning to add in CASSANDRA-17188. >> >>>>>> >> >>>>>> Thanks! >> >>>>>> >> >>>>>> >> >> No PHI in Email: PointClickCare and Collective Medical, A PointClickCare >> >> Company, policies prohibit sending protected health information (PHI) by >> >> email, which may violate regulatory requirements. 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