Realistically, I think we are only likely to see two drivers: * DataStax * ScyllaDB
The latter makes a selling point of being a binary compatible, drop-in replacement for the former. That's why I don't see a need to have an abstraction layer per se. I think we only need "DataStaxConnectionProviderImpl" and "ScyllaDBConnectionProviderImpl" with the difference being which jar is imported by maven. On Tue, Mar 19, 2024 at 2:59 PM David Handermann < [email protected]> wrote: > Mike, > > Thanks for the reply and clarification. > > I agree there is no need to maintain support for the DataStax 3 driver > and Java API, any new components should be built on the latest version > of the driver. > > What we do need going forward is to avoid, if at all possible, having > a DataStax 4 dependency in the Controller Service API. > > One example of this is the WebClientServiceProvider interface. That > Controller Service API does not have any third-party dependencies. The > Controller Service implementation, StandardWebClientServiceProvider, > has a dependency on OkHttp to implement HTTP communication. That is > the kind of abstraction that would be ideal, and I believe that also > aligns with what Matt has described. > > Regards, > David Handermann > > On Tue, Mar 19, 2024 at 1:45 PM Mike Thomsen <[email protected]> > wrote: > > > > ** we can dump v3 **DRIVER** compatibility, since later 4.X Java drivers > > are backward compatible with Cassandra 3 > > > > On Tue, Mar 19, 2024 at 2:43 PM Mike Thomsen <[email protected]> > wrote: > > > > > David, > > > > > > Before we proceed, I think we should make sure we're all understanding > the > > > same problem here. Starting with this: > > > > > > > I believe the CQL protocol is backwards compatible but the Java API > is > > > not. > > > > For example "com.datastax.driver.core.Session" is now > > > > "com.datastax.oss.driver.api.core.session.Session" and there is no > more > > > > "Cluster" class. Might be fairly trivial to fix though, if that's the > > > path > > > > of least resistance. > > > > > > From what I've learned using Cassandra 3 and 4 in my day job and > reading > > > up on this stuff for the sake of discussion, that all tracks. We used > the > > > ~4.11 driver in Spring Boot on both v3 and v4 clusters without issue > during > > > an upgrade. So I don't see any reason to factor in the "changes from > > > DataStax 3 to 4" since the changes were likely a one-off decision > meant to > > > position the driver for better future support and stability. > > > > > > TL;DR, we can dump v3 compatibility and the only thing our users will > > > notice is if we make the controller service totally incompatible with > the > > > one they're already using which is something we can actively avoid. > > > > > > On Tue, Mar 19, 2024 at 2:00 PM David Handermann < > > > [email protected]> wrote: > > > > > >> All, > > >> > > >> I support a Controller Service API abstraction around the Cassandra > > >> Driver. The changes from DataStax 3 to 4 already highlight the need > > >> for that abstraction. The donation of the DataStax Java driver to > > >> Apache [1] also shows the value of providing some level of isolation, > > >> if at all possible. > > >> > > >> I have not taken a close look at the Matt's branch, and the details of > > >> the abstraction are important, but having the abstraction can be > > >> useful to avoid getting back to this same situation. > > >> > > >> Regards, > > >> David Handermann > > >> > > >> [1] https://github.com/apache/cassandra-java-driver/ > > >> > > >> On Tue, Mar 19, 2024 at 12:37 PM Mike Thomsen <[email protected] > > > > >> wrote: > > >> > > > >> > Matt, > > >> > > > >> > I got that. My point was that the Java changes appear to be a one > time > > >> > thing that DataStax did to make a better driver with a much more > > >> > future-proof API. Since Scylla tracks them as closely as possible, I > > >> > suspect that we don't need to plan for a bunch of abstraction to > isolate > > >> > Java changes. > > >> > > > >> > On Tue, Mar 19, 2024 at 11:07 AM Steven Matison < > > >> [email protected]> > > >> > wrote: > > >> > > > >> > > That was kinda where i got stuck and fell out on my branch/jira. > > >> Mike and > > >> > > I wanted to make a new controller service , without backward > > >> compatibility; > > >> > > and remove the duplicate driver/connection properties found in > some > > >> of the > > >> > > processors. > > >> > > > > >> > > I agree taking out all old stuff and making new controller service > > >> makes > > >> > > most sense. 4.x and 5.x should be mostly backwards compatible to > > >> 2&3.x > > >> > > with how it’s used within current processors. > > >> > > > > >> > > > > >> > > > > >> > > On Tue, Mar 19, 2024 at 10:49 AM Matt Burgess < > [email protected]> > > >> > > wrote: > > >> > > > > >> > > > The abstraction is to isolate Java API changes, not protocol > > >> > > compatibility > > >> > > > Changing to the java-driver comes with a number of changes to > the > > >> code > > >> > > (see > > >> > > > Steven's and my branches), if we can abstract that API it should > > >> lead to > > >> > > > more maintainable code in the future by not having to change any > > >> > > > processors, just the controller service implementation. > > >> > > > > > >> > > > > > >> > > > On Tue, Mar 19, 2024 at 10:14 AM Mike Thomsen < > > >> [email protected]> > > >> > > > wrote: > > >> > > > > > >> > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > https://opensource.docs.scylladb.com/stable/using-scylla/drivers/cql-drivers/scylla-java-driver.html > > >> > > > > > > >> > > > > Directly quoting Scylla docs here: > > >> > > > > > > >> > > > > > The Scylla Java Driver is a drop-in replacement for the > > >> DataStax Java > > >> > > > > Driver. As such, no code changes are needed to use this > driver. > > >> > > > > > > >> > > > > On Tue, Mar 19, 2024 at 10:13 AM Mike Thomsen < > > >> [email protected]> > > >> > > > > wrote: > > >> > > > > > > >> > > > > > Matt, > > >> > > > > > > > >> > > > > > I don't think we need to really "abstract above" the drivers > > >> because > > >> > > > the > > >> > > > > > Java DataStax driver appears to support 4.X all the way > back to > > >> 2.X, > > >> > > as > > >> > > > > > well as the enterprise versions from DataStax > > >> > > > > > > > >> > > > > > > > >> https://docs.datastax.com/en/driver-matrix/docs/java-drivers.html > > >> > > > > > > > >> > > > > > Similar situation with Scylla. When I looked at the driver, > it > > >> > > appeared > > >> > > > > to > > >> > > > > > copy verbatim the entire public API of that driver. So I > think > > >> before > > >> > > > we > > >> > > > > > dive into abstractions, it's worth doing a bit more > validation > > >> of > > >> > > these > > >> > > > > > details. IMHO, this might be a much lighter lift than > > >> anticipated. > > >> > > > > > > > >> > > > > > > > >> > > > > > On Mon, Mar 18, 2024 at 4:30 PM Matt Burgess < > > >> [email protected]> > > >> > > > > wrote: > > >> > > > > > > > >> > > > > >> Totally agree, that's what my branch does (see link in > previous > > >> > > > email). > > >> > > > > >> The > > >> > > > > >> more I work with it, the more I think I can abstract it > > >> further from > > >> > > > > their > > >> > > > > >> JDBC-like API but I started with a bunch of delegate > classes > > >> then I > > >> > > > > figure > > >> > > > > >> I'll see where I can consolidate to more abstract > concepts. If > > >> I > > >> > > don't > > >> > > > > >> have > > >> > > > > >> to support Cassandra 3 with the new API, so much the > better. > > >> > > > > >> > > >> > > > > >> Regards, > > >> > > > > >> Matt > > >> > > > > >> > > >> > > > > >> On Mon, Mar 18, 2024 at 4:14 PM David Handermann < > > >> > > > > >> [email protected]> wrote: > > >> > > > > >> > > >> > > > > >> > Matt et al, > > >> > > > > >> > > > >> > > > > >> > It is good to see the background effort on moving > Cassandra > > >> > > > > >> > capabilities in a supportable direction. > > >> > > > > >> > > > >> > > > > >> > I think new Cassandra components will require a > significant > > >> > > > departure > > >> > > > > >> > from current Controller Service abstractions. Right now, > the > > >> > > > existing > > >> > > > > >> > service interface does not provide a clean abstraction > from > > >> the > > >> > > > > >> > Cassandra library, which is part of the reason for the > > >> current > > >> > > > > >> > coupling to the legacy driver version. > > >> > > > > >> > > > >> > > > > >> > Following up from Joe's comments, it seems like the > cleanest > > >> way > > >> > > > > >> > forward is to deprecate the current bundle on the 1.x > > >> branch, and > > >> > > > > >> > remove the current bundle from the main branch. That will > > >> provide > > >> > > a > > >> > > > > >> > clean slate for new Service and Processor > implementations, > > >> without > > >> > > > > >> > concern for uncertain compatibility questions. > > >> > > > > >> > > > >> > > > > >> > Regards, > > >> > > > > >> > David Handermann > > >> > > > > >> > > > >> > > > > >> > On Mon, Mar 18, 2024 at 2:35 PM Matt Burgess < > > >> > > [email protected]> > > >> > > > > >> wrote: > > >> > > > > >> > > > > >> > > > > >> > > What do y'all think about removing the individual > > >> connection > > >> > > > > >> properties > > >> > > > > >> > > from the Cassandra processors for NiFi 2.0 and > requiring a > > >> > > > > >> > > CassandraSessionProvider instead? I think we started > doing > > >> that > > >> > > > > >> elsewhere > > >> > > > > >> > > (Elasticsearch maybe?), I noticed duplicate code in the > > >> > > > > >> > > CassandraSessionProvider and > AbstractCassandraProcessor, > > >> if we > > >> > > > keep > > >> > > > > >> those > > >> > > > > >> > > properties I can refactor them into a utility class. > > >> > > > > >> > > > > >> > > > > >> > > Thanks, > > >> > > > > >> > > Matt > > >> > > > > >> > > > > >> > > > > >> > > > > >> > > > > >> > > On Fri, Mar 15, 2024 at 2:44 PM Steven Matison < > > >> > > > > >> [email protected] > > >> > > > > >> > > > > >> > > > > >> > > wrote: > > >> > > > > >> > > > > >> > > > > >> > > > I got through quite a bit of work to enable 4.x… > > >> > > > > >> > > > > > >> > > > > >> > > > The 3.x pieces that were not backwards compatible is > > >> very edge > > >> > > > use > > >> > > > > >> > case and > > >> > > > > >> > > > could have been done slightly differently but with > work > > >> > > around. > > >> > > > > >> > > > > > >> > > > > >> > > > > https://github.com/steven-matison/nifi/tree/nifi-10120-1 > > >> > > > > >> > > > > > >> > > > > >> > > > > > >> > > > > >> > > > > > >> > > > > >> > > > > > >> > > > > >> > > > > > >> > > > > >> > > > > > >> > > > > >> > > > On Fri, Mar 15, 2024 at 2:30 PM Matt Burgess < > > >> > > > > [email protected]> > > >> > > > > >> > wrote: > > >> > > > > >> > > > > > >> > > > > >> > > > > Oops used the wrong email address so if there have > been > > >> > > > > responses > > >> > > > > >> to > > >> > > > > >> > the > > >> > > > > >> > > > > Cassandra thread since mine I missed them, my bad! > > >> > > > > >> > > > > > > >> > > > > >> > > > > On Fri, Mar 15, 2024 at 2:00 PM Matt Burgess < > > >> > > > > [email protected] > > >> > > > > >> > > > >> > > > > >> > > > wrote: > > >> > > > > >> > > > > > > >> > > > > >> > > > > > I believe the CQL protocol is backwards > compatible > > >> but the > > >> > > > > Java > > >> > > > > >> > API is > > >> > > > > >> > > > > > not. For example > "com.datastax.driver.core.Session" > > >> is now > > >> > > > > >> > > > > > > "com.datastax.oss.driver.api.core.session.Session" > > >> and > > >> > > there > > >> > > > > is > > >> > > > > >> no > > >> > > > > >> > more > > >> > > > > >> > > > > > "Cluster" class. Might be fairly trivial to fix > > >> though, if > > >> > > > > >> that's > > >> > > > > >> > the > > >> > > > > >> > > > > path > > >> > > > > >> > > > > > of least resistance. > > >> > > > > >> > > > > > > > >> > > > > >> > > > > > On Fri, Mar 15, 2024 at 1:40 PM Joe Witt < > > >> > > > [email protected]> > > >> > > > > >> > wrote: > > >> > > > > >> > > > > > > > >> > > > > >> > > > > >> Matt > > >> > > > > >> > > > > >> > > >> > > > > >> > > > > >> I dont know a ton about Cassandra but when I > looked > > >> at > > >> > > > > >> > client/driver > > >> > > > > >> > > > > notes > > >> > > > > >> > > > > >> for 4+ it said it was compatible all the way > back > > >> to 3.x. > > >> > > > > Not > > >> > > > > >> > sure > > >> > > > > >> > > > > what > > >> > > > > >> > > > > >> that means but it surely seems worth exploring. > > >> Also I > > >> > > > dont > > >> > > > > >> know > > >> > > > > >> > if > > >> > > > > >> > > > the > > >> > > > > >> > > > > >> 4.x drivers get rid of the vulnerable bits. > > >> > > > > >> > > > > >> > > >> > > > > >> > > > > >> Thanks > > >> > > > > >> > > > > >> > > >> > > > > >> > > > > >> On Fri, Mar 15, 2024 at 10:39 AM Matt Burgess < > > >> > > > > >> > [email protected]> > > >> > > > > >> > > > > >> wrote: > > >> > > > > >> > > > > >> > > >> > > > > >> > > > > >> > At the very least we should upgrade to > Cassandra > > >> > > 3.11.6: > > >> > > > > >> > > > > >> > > > >> > > > > >> > > > > > > >> > > > > >> > > > >> > > > > > > >> > https://github.com/apache/cassandra/blob/cassandra-3.11.16/CHANGES.txt > > >> > > > > >> > > > > >> > > > >> > > > > >> > > > > >> > On Fri, Mar 15, 2024 at 1:31 PM Matt Burgess < > > >> > > > > >> > [email protected]> > > >> > > > > >> > > > > >> wrote: > > >> > > > > >> > > > > >> > > > >> > > > > >> > > > > >> > > If the community agrees to get rid of > Cassandra > > >> 3 > > >> > > > that'll > > >> > > > > >> > save me > > >> > > > > >> > > > > >> effort > > >> > > > > >> > > > > >> > > on the refactor after I add Cassandra 4 :) > > >> Otherwise > > >> > > > > those > > >> > > > > >> > > > > >> > > vulnerabilities would only be in a "new" > > >> Cassandra 3 > > >> > > > > >> services > > >> > > > > >> > NAR > > >> > > > > >> > > > > that > > >> > > > > >> > > > > >> > > would not be included in the convenience > binary. > > >> > > > > >> > > > > >> > > > > >> > > > > >> > > > > >> > > On Fri, Mar 15, 2024 at 1:28 PM Joe Witt < > > >> > > > > >> [email protected]> > > >> > > > > >> > > > > wrote: > > >> > > > > >> > > > > >> > > > > >> > > > > >> > > > > >> > >> Mike, Matt, > > >> > > > > >> > > > > >> > >> > > >> > > > > >> > > > > >> > >> Happy to hear you both have active efforts > or > > >> are > > >> > > > > >> interested > > >> > > > > >> > in > > >> > > > > >> > > > > doing > > >> > > > > >> > > > > >> > so. > > >> > > > > >> > > > > >> > >> Can you help me understand more > specifically > > >> what > > >> > > that > > >> > > > > >> means > > >> > > > > >> > for > > >> > > > > >> > > > > the > > >> > > > > >> > > > > >> > >> current set of components? > > >> > > > > >> > > > > >> > >> > > >> > > > > >> > > > > >> > >> The CVE hits are concerning and long > standing. > > >> > > > > Supporting > > >> > > > > >> > > > > Cassandra > > >> > > > > >> > > > > >> 3 > > >> > > > > >> > > > > >> > >> implies the current set of dependencies > would > > >> remain > > >> > > > too > > >> > > > > >> > right? > > >> > > > > >> > > > > >> > >> > > >> > > > > >> > > > > >> > >> Is the current set of components we have > ones > > >> we > > >> > > want > > >> > > > to > > >> > > > > >> > retain? > > >> > > > > >> > > > > We > > >> > > > > >> > > > > >> > >> certainly need Cassandra components - but > are > > >> the > > >> > > ones > > >> > > > > we > > >> > > > > >> > have > > >> > > > > >> > > > now > > >> > > > > >> > > > > >> the > > >> > > > > >> > > > > >> > >> right ones? > > >> > > > > >> > > > > >> > >> > > >> > > > > >> > > > > >> > >> Thanks > > >> > > > > >> > > > > >> > >> Joe > > >> > > > > >> > > > > >> > >> > > >> > > > > >> > > > > >> > >> On Fri, Mar 15, 2024 at 10:25 AM Matt > Burgess < > > >> > > > > >> > > > > [email protected]> > > >> > > > > >> > > > > >> > >> wrote: > > >> > > > > >> > > > > >> > >> > > >> > > > > >> > > > > >> > >> > I'm actively working this, I pushed my > > >> branch up > > >> > > in > > >> > > > > case > > >> > > > > >> > anyone > > >> > > > > >> > > > > >> wants > > >> > > > > >> > > > > >> > to > > >> > > > > >> > > > > >> > >> > take a look [1]. The idea is to abstract > the > > >> > > > Cassandra > > >> > > > > >> API > > >> > > > > >> > "up > > >> > > > > >> > > > a > > >> > > > > >> > > > > >> > couple > > >> > > > > >> > > > > >> > >> > levels" and provide implementations for > > >> Cassandra > > >> > > 3, > > >> > > > > 4, > > >> > > > > >> and > > >> > > > > >> > > > > >> eventually > > >> > > > > >> > > > > >> > >> 5. > > >> > > > > >> > > > > >> > >> > For JDBC-like interfaces this is a PITA > > >> because of > > >> > > > the > > >> > > > > >> API > > >> > > > > >> > > > > >> (Statement, > > >> > > > > >> > > > > >> > >> > PreparedStatement, BoundStatement, > ResultSet, > > >> > > etc.) > > >> > > > > but > > >> > > > > >> I'm > > >> > > > > >> > > > > hoping > > >> > > > > >> > > > > >> we > > >> > > > > >> > > > > >> > >> can > > >> > > > > >> > > > > >> > >> > find a common pattern for abstracting the > > >> > > > third-party > > >> > > > > >> > library > > >> > > > > >> > > > > >> > >> > implementation and API from the NiFi > > >> component > > >> > > > > >> (Processor, > > >> > > > > >> > > > > >> > >> > ControllerService, etc.) API. I think > we're > > >> doing > > >> > > > > >> something > > >> > > > > >> > > > > similar > > >> > > > > >> > > > > >> > for > > >> > > > > >> > > > > >> > >> > Kafka? > > >> > > > > >> > > > > >> > >> > > > >> > > > > >> > > > > >> > >> > Regards, > > >> > > > > >> > > > > >> > >> > Matt > > >> > > > > >> > > > > >> > >> > > > >> > > > > >> > > > > >> > >> > [1] > > >> https://github.com/mattyb149/nifi/tree/cassy4 > > >> > > > > >> > > > > >> > >> > > > >> > > > > >> > > > > >> > >> > > > >> > > > > >> > > > > >> > >> > On Fri, Mar 15, 2024 at 8:43 AM Mike > Thomsen > > >> < > > >> > > > > >> > > > > >> [email protected]> > > >> > > > > >> > > > > >> > >> > wrote: > > >> > > > > >> > > > > >> > >> > > > >> > > > > >> > > > > >> > >> > > That’s been on my todo list for a > little > > >> while > > >> > > but > > >> > > > > >> things > > >> > > > > >> > > > kept > > >> > > > > >> > > > > >> > coming > > >> > > > > >> > > > > >> > >> up. > > >> > > > > >> > > > > >> > >> > > I think I could get started on that > now. > > >> Based > > >> > > on > > >> > > > my > > >> > > > > >> > initial > > >> > > > > >> > > > > >> > research > > >> > > > > >> > > > > >> > >> it > > >> > > > > >> > > > > >> > >> > > appears that scylla uses the exact same > > >> api as > > >> > > > > >> datastax > > >> > > > > >> > so > > >> > > > > >> > > > > >> > supporting > > >> > > > > >> > > > > >> > >> > both > > >> > > > > >> > > > > >> > >> > > in a cql bundle should theoretically be > > >> fairly > > >> > > > easy. > > >> > > > > >> > > > > >> > >> > > > > >> > > > > >> > > > > >> > >> > > > > >> > > > > >> > > > > >> > >> > > Sent from my iPhone > > >> > > > > >> > > > > >> > >> > > > > >> > > > > >> > > > > >> > >> > > > On Mar 14, 2024, at 6:18 PM, Joe > Witt < > > >> > > > > >> > [email protected]> > > >> > > > > >> > > > > >> wrote: > > >> > > > > >> > > > > >> > >> > > > > > >> > > > > >> > > > > >> > >> > > > Team, > > >> > > > > >> > > > > >> > >> > > > > > >> > > > > >> > > > > >> > >> > > > Cassandra remains a really important > > >> system to > > >> > > > be > > >> > > > > >> able > > >> > > > > >> > to > > >> > > > > >> > > > > send > > >> > > > > >> > > > > >> > data > > >> > > > > >> > > > > >> > >> to. > > >> > > > > >> > > > > >> > >> > > > However, it seems like we've not > > >> maintained > > >> > > > these > > >> > > > > >> > well. We > > >> > > > > >> > > > > >> have > > >> > > > > >> > > > > >> > >> what > > >> > > > > >> > > > > >> > >> > > > appears to be at least a full > generation > > >> > > behind > > >> > > > on > > >> > > > > >> > client > > >> > > > > >> > > > > >> versions > > >> > > > > >> > > > > >> > >> (we > > >> > > > > >> > > > > >> > >> > > are > > >> > > > > >> > > > > >> > >> > > > on 3x vs 4x which is the latest > stable > > >> with 5x > > >> > > > > >> > apparently > > >> > > > > >> > > > > >> coming > > >> > > > > >> > > > > >> > >> > > shortly). > > >> > > > > >> > > > > >> > >> > > > > > >> > > > > >> > > > > >> > >> > > > We have components to send data, > query > > >> data, > > >> > > and > > >> > > > > use > > >> > > > > >> > > > > Cassandra > > >> > > > > >> > > > > >> as > > >> > > > > >> > > > > >> > a > > >> > > > > >> > > > > >> > >> > cache > > >> > > > > >> > > > > >> > >> > > > store. We have older mechanisms for > > >> json/avro > > >> > > > and > > >> > > > > >> > publish > > >> > > > > >> > > > > >> > >> mechanisms > > >> > > > > >> > > > > >> > >> > for > > >> > > > > >> > > > > >> > >> > > > records. > > >> > > > > >> > > > > >> > >> > > > > > >> > > > > >> > > > > >> > >> > > > The libraries we do have depend on > > >> outdated > > >> > > > > >> versions of > > >> > > > > >> > > > Guava > > >> > > > > >> > > > > >> and > > >> > > > > >> > > > > >> > >> > result > > >> > > > > >> > > > > >> > >> > > in > > >> > > > > >> > > > > >> > >> > > > many CVE hits. > > >> > > > > >> > > > > >> > >> > > > > > >> > > > > >> > > > > >> > >> > > > I am inclined to think we should > > >> deprecate the > > >> > > > 1.x > > >> > > > > >> > > > components > > >> > > > > >> > > > > >> and > > >> > > > > >> > > > > >> > >> > remove > > >> > > > > >> > > > > >> > >> > > > them as-is from the 2.x line. Then > > >> > > re-introduce > > >> > > > > >> them > > >> > > > > >> > with > > >> > > > > >> > > > > >> record > > >> > > > > >> > > > > >> > >> only > > >> > > > > >> > > > > >> > >> > > > interfaces and built against the > latest > > >> stable > > >> > > > > >> > > > > >> > >> > > Cassandra/Datastax/ScyllaDB > > >> > > > > >> > > > > >> > >> > > > interfaces. > > >> > > > > >> > > > > >> > >> > > > > > >> > > > > >> > > > > >> > >> > > > I'd love to hear thoughts from those > > >> closer to > > >> > > > > this > > >> > > > > >> > space > > >> > > > > >> > > > > both > > >> > > > > >> > > > > >> as > > >> > > > > >> > > > > >> > a > > >> > > > > >> > > > > >> > >> > user > > >> > > > > >> > > > > >> > >> > > > and developer so we can make good > next > > >> steps. > > >> > > > > >> > > > > >> > >> > > > > > >> > > > > >> > > > > >> > >> > > > Thanks > > >> > > > > >> > > > > >> > >> > > > > >> > > > > >> > > > > >> > >> > > > >> > > > > >> > > > > >> > >> > > >> > > > > >> > > > > >> > > > > >> > > > > >> > > > > >> > > > >> > > > > >> > > > > >> > > >> > > > > >> > > > > > > > >> > > > > >> > > > > > > >> > > > > >> > > > > > >> > > > > >> > > > >> > > > > >> > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >
