You have my +1
On Wed, Mar 5, 2025 at 12:16 PM Benedict <bened...@apache.org> wrote: > > Correct, these caveats should only apply to tables that have opted-in to > accord. > > On 5 Mar 2025, at 20:08, Jeremiah Jordan <jerem...@apache.org> wrote: > > > So great to see all this hard work about to pay off! > > On the questions/concerns front, the only concern I would have towards > merging this to trunk is if any of the caveats apply when someone is not > using Accord. Assuming they only apply when the feature flag is enabled, I > see no reason not to get this merged into trunk once everyone involved is > happy with the state of it. > > -Jeremiah > > On Mar 5, 2025 at 12:15:23 PM, Benedict Elliott Smith <bened...@apache.org> > wrote: >> >> That depends on all of you lovely people :D >> >> I think we should have finished merging everything we want before QA by >> ~Monday; certainly not much later. >> >> I think we have some upgrade and python dtest failures to address as well. >> >> So it could be pretty soon if the community is supportive. >> >> On 5 Mar 2025, at 17:22, Patrick McFadin <pmcfa...@gmail.com> wrote: >> >> >> What is the timing for starting the merge process? I'm asking because >> >> I have (yet another) presentation and this would be a cool update. >> >> >> On Wed, Mar 5, 2025 at 1:22 AM Benedict Elliott Smith >> >> <bened...@apache.org> wrote: >> >> > >> >> > Thanks everyone. >> >> > >> >> > Jon - your help will be greatly appreciated. We’ll let you know when we’ve >> > got the cycles to invest in performance work (hopefully fairly soon). I >> > expect the first step will be improving visibility so we can better >> > understand what the system is doing (particularly the caching layers), but >> > we can dig in together when ready. >> >> > >> >> > On 4 Mar 2025, at 18:15, Jon Haddad <j...@rustyrazorblade.com> wrote: >> >> > >> >> > Very exciting! >> >> > >> >> > I have a client that's very interested in Accord, so I should have budget >> > to dig into it, especially on the performance side of things. >> >> > >> >> > Jon >> >> > >> >> > On Tue, Mar 4, 2025 at 9:57 AM Dmitry Konstantinov <netud...@gmail.com> >> > wrote: >> >> >> >> >> >> Thank you to all Accord and TCM contributors, it is really exciting to >> >> see a development of such huge and wonderful features moving forward and >> >> opening the door to the new Cassandra epoch! >> >> >> >> >> >> On Tue, 4 Mar 2025 at 20:45, Blake Eggleston <bl...@ultrablake.com> wrote: >> >> >>> >> >> >>> Thanks Benedict! >> >> >>> >> >> >>> I’m really excited to see accord reach this milestone, even with these >> >>> caveats. You seem to have left yourself off the list of contributors >> >>> though, even though you’ve been a central figure in its development :) >> >>> So thanks to all accord & tcm contributors, including Benedict, for >> >>> making this possible! >> >> >>> >> >> >>> On Tue, Mar 4, 2025, at 8:00 AM, Benedict Elliott Smith wrote: >> >> >>> >> >> >>> Hi everyone, >> >> >>> >> >> >>> It’s been exactly 3.5 years since the first commit to cassandra-accord. >> >>> Yes, really, it’s been that long. >> >> >>> >> >> >>> We will be starting to validate the feature against real workloads in >> >>> the near future, so we can’t sensibly push off merging much longer. The >> >>> following is a brief run-down of the state of play. There are no known >> >>> bugs, but there remain a number of caveats we will be incrementally >> >>> addressing in the run-up to a full release: >> >> >>> >> >> >>> [1] Accord is likely to be SLOW until further optimisations are >> >>> implemented >> >> >>> [2] Schema changes have a number of hard edges >> >> >>> [3] Validation is ongoing, so there are likely still a number of bugs to >> >>> shake out >> >> >>> [4] Many operator visibility/tooling/documentation improvements are >> >>> pending >> >> >>> >> >> >>> To expand a little: >> >> >>> >> >> >>> [1] As of the last experiment we conducted, accord’s throughput was poor >> >>> - also leading to higher LAN latencies. We have done no WAN experiments >> >>> to date, but the protocol guarantees should already achieve better >> >>> round-trip performance, in particular under contention. Improving >> >>> throughput will be the main focus of attention once we are satisfied the >> >>> protocol is otherwise stable, but our focus remains validation for the >> >>> moment. >> >> >>> [2] Schema changes have not yet been well integrated with TCM. Dropping >> >>> a table for instance will currently cause problems if nodes are offline. >> >> >>> [3] We have a range of validations we are already performing against >> >>> cassandra-accord directly, and against its integration with Cassandra in >> >>> cep-15-accord. We have run hundreds of billions of simulated >> >>> transactions, and are still discovering some minor fault every few >> >>> billion simulated transactions or so. There remains a lot more simulated >> >>> validation to explore, as well as with real clusters serving real >> >>> workloads. >> >> >>> [4] There are already a range of virtual tables for exploring internal >> >>> state in Accord, and reasonably good metric support. However, tracing is >> >>> not yet supported, and our metric and virtual table integrations need >> >>> some further development. >> >> >>> [5] There are also other edge cases to address such as ensuring we do >> >>> not reuse HLCs after restart, supporting ByteOrderPartitioner, and live >> >>> migration from/to Paxos is undergoing fine-tuning and validation; >> >>> probably there are some other things I am forgetting. >> >> >>> >> >> >>> Altogether the feature is fairly mature, despite these caveats. This is >> >>> the fruit of the labour of a long list of contributors, including >> >>> Aleksey Yeschenko, Alex Petrov, Ariel Weisberg, Blake Eggleston, Caleb >> >>> Rackliffe and David Capwell, and represents a huge undertaking. It also >> >>> wouldn’t have been possible without the work of Alex Petrov, Marcus >> >>> Eriksson and Sam Tunnicliffe on delivering transactional cluster >> >>> metadata. I hope you will join me in thanking them all for their >> >>> contributions. >> >> >>> >> >> >>> Alex has also kindly produced some initial overview documentation for >> >>> developers, that can be found here: >> >>> https://github.com/apache/cassandra/blob/cep-15-accord/doc/modules/cassandra/pages/developing/accord/index.adoc. >> >>> This will be expanded as time permits. >> >> >>> >> >> >>> Does anyone have any questions or concerns? >> >> >>> >> >> >>> >> >> >> >> >> >> >> >> >> -- >> >> >> Dmitry Konstantinov >> >> > >> >> > >> >>
