There's a tactical issue, too, that virtual tables require native transport to be up before it's usable, so for things pre-startup (e.g. querying streaming state during bootstrap), so I don't think nodetool/jmx dies entirely ever (or, a non-client-facing-virtual-tables-only port has to be created, but that's much more involved obviously)
On Thu, Jul 15, 2021 at 9:18 AM Lorina Poland <lor...@datastax.com> wrote: > I think it is important to keep in mind that users may be utilizing > nodetool programmatically, in scripts. Obviously, those scripts could use > calls to cqlsh as an alternative, but I'm a fan of keeping nodetool intact, > building out virtual table capability, and then deprecating nodetool. In > other words, only deprecate/remove nodetool commands once a *whole* > replacement is available. And then deprecate slowly, perhaps with migration > help in the docs for nodetool -> virtual tables. > > Lorina > > On Thu, Jul 15, 2021 at 6:59 AM Paulo Motta <pauloricard...@gmail.com> > wrote: > > > Perhaps one approach to expose VirtualTables via nodetool without > requiring > > the user to provide CQL credentials would be to provide a generic > > StorageServiceMBean.queryVirtualTable(String name) JMX method returning a > > TabularData result. This would allow to keep a consistent nodetool > frontend > > to users while progressively switching the backend from JMX to > > VirtualTables. > > > > We could create a framework to automatically expose a basic nodetool > > getter/setter command whenever a new virtual table is added, making the > new > > feature visible to non-power nodetool users while requiring little > > additional effort from the VirtualTable implementor. > > > > When migrating commands from JMX to VirtualTables we could just update > the > > legacy nodetool command implementation to access the virtual table via > the > > generic StorageServiceMBean.queryVirtualTable(String name) method while > > keeping the output consistent with the previous implementation, and > > deprecating their JMX counterpart. > > > > Ultimately when all commands are migrated from JMX to VirtualTables we > > could decide if we want to keep the nodetool CLI, acessing all virtual > > tables via the generic JMX virtual table accessor, or to deprecate > nodetool > > altogether and tell users to query virtual tables directly via cqlsh > > instead. > > > > Em qui., 15 de jul. de 2021 às 10:34, Paulo Motta < > > pauloricard...@gmail.com> > > escreveu: > > > > > Thanks for bringing this discussion Benjamin. I raised a similar point > in > > > CASSANDRA-16725 <https://issues.apache.org/jira/browse/CASSANDRA-16725 > > > > > and it may become a recurrent topic now the code freeze is lifted and > > more > > > contributors will want to add new administrative commands to nodetool > so > > > it's important that we discuss and decide a consistent approach to this > > > transition moving forward. > > > > > > I was planning to write a CEP to propose a migration strategy from JMX > to > > > Virtual tables but since this discussion came before I will detail my > > > thoughts so far. > > > > > > I think that we should add new commands exclusively to Virtual Tables > and > > > progressively migrate existing nodetool/JMX commands to > VirtualTables/CQL > > > until we ultimately get rid of JMX/nodetool. Nevertheless, from the > user > > > point of view it may be inconvenient/confusing to have administrative > > > commands split between different interfaces so we need to think about > > this > > > transition carefully to provide the best possible user experience. > > > > > > My motivation for CASSANDRA-16513 < > > > https://issues.apache.org/jira/browse/CASSANDRA-16513> was that we're > > > already providing some functionalities exclusively via Virtual Tables, > so > > > these features may not be visible to non-power users which are > accustomed > > > to the nodetool CLI interface for admin commands. The original plan for > > > that ticket was to make nodetool abstract away the underlying interface > > > (JMX, CQL) for administrative commands, so we would expose admin > > > functionality via the same CLI interface (nodetool) to users while > > > progressively migrating the backend from JMX to CQL/VirtualTables. > > > > > > Some people raised the concern that this could cause confusion among > > users > > > about which credentials to use if JMX or CQL for nodetool. Based on > this > > > feedback I adapted the proposal to create an entirely different > > > administrative CLI tool (which I called admintool) to access/modify > > virtual > > > tables. In this proposal new administrative commands would be added > > > exclusively to Virtual Tables and would automatically land on this > tool, > > > and legacy nodetool commands (via JMX) would be progressively migrated > to > > > admintool (CQL/VT) until the migration is completed. The drawback of > this > > > alternative proposal is that it would still split administrative > commands > > > between different CLI tools. > > > > > > So, if we decide to stop adding new admin functionality to JMX we have > a > > > few options to make this transition smoother for our users: > > > 1) Do nothing and tell users some admin functionalities will be > > accessible > > > exclusively via cqlsh/virtual tables - imo this option is the least > > > user-friendly. > > > 2) Make nodetool hybrid and provide a consistent interface to users > while > > > abstracting away the backend (JMX/CQL) > > > 3) Create a new CLI tool (admintool) to provide CLI access to virtual > > > tables and tell users to use both nodetool and admintool. > > > > > > I personally think option 2 is the least disruptive to users during the > > > transition phase since people are already used to using nodetool so we > > can > > > provide a seamless transition to JMX while keeping the CLI tool for > > legacy > > > users. Even though there are concerns of confusion of which credentials > > to > > > use on nodetool if we support both interfaces, we can make sure this is > > > well documented. > > > > > > Em qui., 15 de jul. de 2021 às 09:35, Benjamin Lerer < > ble...@apache.org> > > > escreveu: > > > > > >> Hi everyone, > > >> > > >> When Virtual Tables/System Views were introduced in 4.0 it was with > the > > >> intention to provide a more friendly way than JMX and NodeTool to > manage > > >> and monitor nodes. > > >> > > >> In CASSANDRA-16404 < > > https://issues.apache.org/jira/browse/CASSANDRA-16404 > > >> >, > > >> Sam raises the point that it might make sense from now on to stop > adding > > >> functionalities to NodeTool and to provide them through Virtual > Tables. > > >> My initial feeling was that we could provide both until we decided to > > >> deprecate NodeTool but that would require some extra work and as such > > >> might > > >> not be a good strategy. > > >> > > >> What is your opinion on this? > > >> > > > > > >
