+1 for separate repo. Especially on git. Maybe make it a submodule.
Rahul On Aug 21, 2018, 3:33 PM -0500, Stefan Podkowinski <s...@apache.org>, wrote: > I'm also currently -1 on the in-tree option. > > Additionally to what Aleksey mentioned, I also don't see how we could > make this work with the current build and release process. Our scripts > [0] for creating releases (tarballs and native packages), would need > significant work to add support for an independent side-car. Our ant > based build process is also not a great start for adding new tasks, let > alone integrating other tool chains for web components for a potential UI. > > [0] https://git-wip-us.apache.org/repos/asf?p=cassandra-builds.git > > > On 21.08.18 19:20, Aleksey Yeshchenko wrote: > > Sure, allow me to elaborate - at least a little bit. But before I do, just > > let me note that this wasn’t a veto -1, just a shorthand for “I don’t like > > this option”. > > > > It would be nice to have sidecar and C* version and release cycles fully > > decoupled. I know it *can* be done when in-tree, but the way we vote on > > releases with tags off current branches would have to change somehow. > > Probably painfully. It would be nice to be able to easily enforce freezes, > > like the upcoming one, on the whole C* repo, while allowing feature > > development on the sidecar. It would be nice to not have sidecar commits in > > emails from commits@ mailing list. It would be nice to not have C* CI > > trigger necessarily on sidecar commits. Groups of people working on the two > > repos will mostly be different too, so what’s the point in sharing the repo? > > > > Having an extra repo with its own set of branches is cheap and easy - we > > already do that with dtests. I like cleanly separated things when coupling > > is avoidable. As such I would prefer the sidecar to live in a separate new > > repo, while still being part of the C* project. > > > > — > > AY > > > > On 21 August 2018 at 17:06:39, sankalp kohli (kohlisank...@gmail.com) wrote: > > > > Hi Aleksey, > > Can you please elaborate on the reasons for your -1? This > > way we can make progress towards any one approach. > > Thanks, > > Sankalp > > > > On Tue, Aug 21, 2018 at 8:39 AM Aleksey Yeshchenko <alek...@apple.com> > > wrote: > > > > > FWIW I’m strongly -1 on in-tree approach, and would much prefer a separate > > > repo, dtest-style. > > > > > > — > > > AY > > > > > > On 21 August 2018 at 16:36:02, Jeremiah D Jordan ( > > > jeremiah.jor...@gmail.com) wrote: > > > > > > I think the following is a very big plus of it being in tree: > > > > > * Faster iteration speed in general. For example when we need to add a > > > > > new > > > > > JMX endpoint that the sidecar needs, or change something from JMX to a > > > > > virtual table (e.g. for repair, or monitoring) we can do all changes > > > > > including tests as one commit within the main repository and don't > > > have > > > > > to > > > > > commit to main repo, sidecar repo, > > > > > > I also don’t see a reason why the sidecar being in tree means it would not > > > work in a mixed version cluster. The nodes themselves must work in a mixed > > > version cluster during a rolling upgrade, I would expect any management > > > side car to operate in the same manor, in tree or not. > > > > > > This tool will be pretty tightly coupled with the server, and as someone > > > with experience developing such tightly coupled tools, it is *much* easier > > > to make sure you don’t accidentally break them if they are in tree. How > > > many times has someone updated some JMX interface, updated nodetool, and > > > then moved on? Breaking all the external tools not in tree, without > > > realizing it. The above point about being able to modify interfaces and > > > the > > > side car in the same commit is huge in terms of making sure someone > > > doesn’t > > > inadvertently break the side car while fixing something else. > > > > > > -Jeremiah > > > > > > > > > > On Aug 21, 2018, at 10:28 AM, Jonathan Haddad <j...@jonhaddad.com> > > > wrote: > > > > > > > > Strongly agree with Blake. In my mind supporting multiple versions is > > > > mandatory. As I've stated before, we already do it with Reaper, I'd > > > > consider it a major misstep if we couldn't support multiple with the > > > > project - provided admin tool. It's the same reason dtests are separate > > > - > > > > they work with multiple versions. > > > > > > > > The number of repos does not affect distribution - if we want to ship > > > > Cassandra with the admin / repair tool (we should, imo), that can be > > > part > > > > of the build process. > > > > > > > > > > > > > > > > > > > > On Mon, Aug 20, 2018 at 9:21 PM Blake Eggleston <beggles...@apple.com> > > > > wrote: > > > > > > > > > If the sidecar is going to be on a different release cadence, or > > > support > > > > > interacting with mixed mode clusters, then it should definitely be in > > > a > > > > > separate repo. I don’t even know how branching and merging would work > > > in a > > > > > repo that supports 2 separate release targets and/or mixed mode > > > > > compatibility, but I’m pretty sure it would be a mess. > > > > > > > > > > As a cluster management tool, mixed mode is probably going to be a > > > > > goal > > > at > > > > > some point. As a new project, it will benefit from not being tied to > > > the C* > > > > > release cycle (which would probably delay any sidecar release until > > > > > whenever 4.1 is cut). > > > > > > > > > > > > > > > On August 20, 2018 at 3:22:54 PM, Joseph Lynch (joe.e.ly...@gmail.com) > > > > > > > > wrote: > > > > > > > > > > I think that the pros of incubating the sidecar in tree as a tool > > > first > > > > > outweigh the alternatives at this point of time. Rough tradeoffs that > > > I > > > > > see: > > > > > > > > > > Unique pros of in tree sidecar: > > > > > * Faster iteration speed in general. For example when we need to add a > > > > > new > > > > > JMX endpoint that the sidecar needs, or change something from JMX to a > > > > > virtual table (e.g. for repair, or monitoring) we can do all changes > > > > > including tests as one commit within the main repository and don't > > > have > > > > > to > > > > > commit to main repo, sidecar repo, and dtest repo (juggling version > > > > > compatibility along the way). > > > > > * We can in the future more easily move serious background > > > functionality > > > > > like compaction or repair itself (not repair scheduling, actual > > > > > repairing) > > > > > into the sidecar with a single atomic commit, we don't have to do two > > > > > phase > > > > > commits where we add some IPC mechanism to allow us to support it in > > > > > both, > > > > > then turn it on in the sidecar, then turn it off in the server, etc... > > > > > * I think that the verification is much easier (sounds like Jonathan > > > > > disagreed on the other thread, I could certainly be wrong), and we > > > don't > > > > > have to worry about testing matrices to assure that the sidecar works > > > > > with > > > > > various versions as the version of the sidecar that is released with > > > that > > > > > version of Cassandra is the only one we have to certify works. If > > > people > > > > > want to pull in new versions or maintain backports they can do that at > > > > > their discretion/testing. > > > > > * We can iterate and prove value before committing to a choice. Since > > > it > > > > > will be a separate artifact from the start we can always move the > > > > > artifact > > > > > to a separate repo later (but moving the other way is harder). > > > > > * Users will get the sidecar "for free" when they install the daemon, > > > > > they > > > > > don't need to take affirmative action to e.g. be able to restart their > > > > > cluster, run repair, or back their data up; it just comes out of the > > > box > > > > > for free. > > > > > > > > > > Unique pros of a separate repository sidecar: > > > > > * We can use a more modern build system like gradle instead of ant > > > > > * Merging changes is less "scary" I guess (I feel like if you're not > > > > > touching the daemon this is already true but I could see this being > > > less > > > > > worrisome for some). > > > > > * Releasing a separate artifact is somewhat easier from a separate > > > repo > > > > > (especially if we have gradle which makes e.g. building debs and rpms > > > > > trivial). > > > > > * We could backport to previous versions without getting into > > > arguments > > > > > about bug fixes vs features. > > > > > * Committers could be different from the main repo, which ... may be a > > > > > useful thing > > > > > > > > > > Non unique pros of a sidecar (could be achieved in the main repo or in > > > a > > > > > separate repo): > > > > > * A separate build artifact .jar/.deb/.rpm that can be installed > > > > > separately. It's slightly easier with a separate repo but certainly > > > not > > > > > out > > > > > of reach within a single repo (indeed the current patch already > > > > > creates > > > a > > > > > separate jar, and we could create a separate .deb reasonably easily). > > > > > Personally I think having a separate .deb/.rpm is premature at this > > > point > > > > > (for companies that really want it they can build their own packages > > > > > using > > > > > the .jars), but I think it really is a distracting issue from where > > > the > > > > > patch should go as we can always choose to remove experimental .jar > > > files > > > > > that the main daemon doesn't touch. > > > > > * A separate process lifecycle. No matter where the sidecar goes, we > > > get > > > > > the benefit of restarting it being less dangerous for availability > > > than > > > > > restarting the main daemon. > > > > > > > > > > That all being said, these are strong opinions weakly held and I would > > > > > rather get something actually committed so that we can prove value one > > > > > way > > > > > or the other and am therefore, of course, happy to put sidecar patches > > > > > wherever someone can review and commit it. > > > > > > > > > > -Joey > > > > > > > > > > On Mon, Aug 20, 2018 at 1:52 PM sankalp kohli <kohlisank...@gmail.com> > > > > > > > > wrote: > > > > > > > > > > > Hi, > > > > > > I am starting a new thread to get consensus on where the side car > > > > > > should be contributed. > > > > > > > > > > > > Please send your responses with pro/cons of each approach or any > > > other > > > > > > approach. Please be clear which approach you will pick while still > > > > > giving > > > > > > pros/cons of both approaches. > > > > > > > > > > > > Thanks. > > > > > > Sankalp > > > > > > > > > > > > > > > > > > > > > > > -- > > > > Jon Haddad > > > > http://www.rustyrazorblade.com > > > > twitter: rustyrazorblade > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: dev-unsubscr...@cassandra.apache.org > > > For additional commands, e-mail: dev-h...@cassandra.apache.org > > > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@cassandra.apache.org > For additional commands, e-mail: dev-h...@cassandra.apache.org >
