It looks like there is a potential solution to the indeterministic bytebuffer: https://docs.oracle.com/en/java/javase/24/docs/api/java.base/java/lang/foreign/MemoryLayout.html & https://archive.fosdem.org/2020/schedule/event/bytebuffers/
Thanks, Vivekanand K. On Fri, May 9, 2025, 8:59 PM Vivekanand Koya <13vivekk...@gmail.com> wrote: > Made some progress. After adding <compilerarg value="-Xlint:unchecked"/> > throughout build.xml and compiling the 5.03 branch with openjdk 17.0.15 > 2025-04-15 > OpenJDK Runtime Environment Temurin-17.0.15+6 (build 17.0.15+6) I got a > build Failed error at the same position in exception. Please see: > https://github.com/apache/cassandra/pull/4152 > > While debugging, it appears there is an idiosyncrasy how Netty was used > for efficient network operations. The unsafe casting was highlighted by the > compiler and eventually made its way to runtime. I drew a dependency graph > between types. It appears Java natively supports such functionality with > Project Loom (https://openjdk.org/jeps/444) ( > https://inside.java/2021/05/10/networking-io-with-virtual-threads/). I > understand that this is only part of the story. Please correct me if my > reasoning is wrong, wish to learn from your experience. Wish to see your > insights. > > Thanks, > Vivekanand K. > > On Fri, May 9, 2025 at 1:30 PM Brandon Williams <dri...@gmail.com> wrote: > >> We thought we had this figured out when we did the big bang switch to >> ByteBuffers, then spent years finding subtle bugs that the tests >> didn't. >> >> Kind Regards, >> Brandon >> >> On Fri, May 9, 2025 at 3:24 PM Jon Haddad <j...@rustyrazorblade.com> >> wrote: >> > >> > There’s a pretty simple solution here - breaking it up into several >> smaller patches. >> > >> > * Any changes should include tests that validate the checks are used >> correctly. >> > * It should also alleviate any issues with code conflicts and rebasing >> as the merges would happen slowly over time rather than all at once. >> > * If there’s two committers willing to spend time and work with OP on >> this, that should be enough to move it forward. >> > * There's a thread on user@ right now [1] where someone *just* ran >> into this issue, so I'd say addressing that one is a reasonable starting >> point. >> > >> > [1] https://lists.apache.org/thread/ykkwhjdpgyqzw5xtol4v5ysz664bxxl3 >> > >> > >> > >> > Jon >> > >> > >> > On Fri, May 9, 2025 at 12:16 PM C. Scott Andreas <sc...@paradoxica.net> >> wrote: >> >> >> >> My thinking is most closely aligned with Blake and Benedict’s views >> here. >> >> >> >> For the specific refactor in question, I support adoption of the >> language feature for new code or to cut existing code over to the new >> syntax as changes are made to the respective areas of the codebase. But I >> don’t support a sweeping project-wide refactor on trunk in this case. >> >> >> >> Here is my thinking: >> >> >> >> - If there are 2000 target sites for the refactor, that means this is >> going to be a 5000+ line diff. >> >> - The safety improvement here is marginal but nonzero. >> >> - If we have a 5000 line refactor, it should accomplish a significant >> and compelling purpose in the project. >> >> - Any execution of the refactor will require manual review of each of >> those 2000 refactor sites on the part of the implementer and two reviewers. >> >> - Since the check is compile-time, we’d learn that by the initial >> refactor the first time it’s compiled, and we short-circuit to having >> gained 100% of the value by being able to fix the broken callsites. >> >> - The act of that per-call site review would inform us as to whether >> we had incorrect casts; and we would immediately achieve the value of the >> “safer” approach by having identified the bugs. >> >> - 2x reviewer coverage for a 5000 line patch set is a significant >> commitment of reviewer resources. These reviewer resources have significant >> opportunity cost and can put to a better purpose. >> >> - Blake/others mention that such refactors create conflicts when bug >> fixes are backported to previous releases, requiring refactors of those >> rebased patches to bring fixes to versions that predate the large refactor. >> >> >> >> I think this is a good language feature. I think we should use it. I >> think it’d be completely reasonable to cut existing syntax over to it as we >> make changes to the respective subsystems. >> >> >> >> But I wouldn’t do a big bang refactor in this case. The juice isn’t >> worth the squeeze for me. >> >> >> >> - Scott >> >> >> >> On May 9, 2025, at 11:33 AM, Blake Eggleston <bl...@ultrablake.com> >> wrote: >> >> >> >> >> >> >> >> No one is treating the codebase like a house of cards that can’t be >> touched. >> >> >> >> In this case I think the cost/risk of doing this change outweighs the >> potential benefits the project might see from it. Josh counts ~2000 >> instances where we’re casting objects so we’re talking about a >> not-insignificant change which may introduce it’s own bugs. Even if no new >> bugs are introduced, this will be an refactor annoyance for projects in >> development, but the real concern I have with any large change is how it >> complicates the process of fixing bugs across versions. On the other hand, >> I don’t think that incorrectly casting objects has historically been a >> source of pain for us, so it seems like the benefit would be small if any. >> >> >> >> On Fri, May 9, 2025, at 10:38 AM, Jon Haddad wrote: >> >> >> >> Why not? >> >> >> >> Personally, I hate the idea of treating a codebase (any codebase) like >> a house of cards that can't be touched. It never made sense to me to try >> to bundle new features / bug fixes with improvements to code quality. >> >> >> >> Making the code more reliable should be a goal in itself, rather than >> a side effect of other work. >> >> >> >> Jon >> >> >> >> >> >> >> >> On Fri, May 9, 2025 at 10:31 AM Blake Eggleston <bl...@ultrablake.com> >> wrote: >> >> >> >> >> >> This seems like a cool feature that will be useful in future >> development work, but not something we should be proactively refactoring >> the project to make use of. >> >> >> >> On Fri, May 9, 2025, at 10:18 AM, Vivekanand Koya wrote: >> >> >> >> I would say that https://openjdk.org/jeps/394 (instanceOf) aims to >> provide safer and less poisoning in the code by default. Instead of having >> a production server halt/impaired due to a RuntimeException, instead it is >> verified at compile time. If a new language feature makes code more robust >> and addresses a hazardous, historical design choice, I believe it's time >> has arrived. Curious to see what everyone thinks. >> >> >> >> Thanks, >> >> Vivekanand K. >> >> >> >> On Fri, May 9, 2025 at 9:51 AM Josh McKenzie <jmcken...@apache.org> >> wrote: >> >> >> >> >> >> I would like to refactor the codebase (Trunk 5+) to eliminate unsafe >> explicit casting with instanceOf. >> >> >> >> We have a rich history of broad sweeping refactors dying on the rocks >> of the community's aversion to instability and risk w/out a concrete >> outcome we're trying to achieve. :) >> >> >> >> All of which is to say: do we have examples of instanceOf casting >> blowing things up for users that would warrant going through the codebase >> to tidy this up? Between src/java and test/unit and test/distributed we >> have around 2,000 occurrences of this pattern. >> >> >> >> On Fri, May 9, 2025, at 10:14 AM, Vivekanand Koya wrote: >> >> >> >> Sounds great. I would like to refactor the codebase (Trunk 5+) to >> eliminate unsafe explicit casting with instanceOf. >> >> >> >> Thanks, >> >> Vivekanand >> >> >> >> On Fri, May 9, 2025, 5:19 AM Benedict Elliott Smith < >> bened...@apache.org> wrote: >> >> >> >> Yep, that approach seems more than sufficient to me. No need for lots >> of ceremony, but good to keep everyone in the decision loop. >> >> >> >> On 9 May 2025, at 13:10, Josh McKenzie <jmcken...@apache.org> wrote: >> >> >> >> I think it doesn’t cost us much to briefly discuss new language >> features before using them. >> >> >> >> I had that thought as well but on balance my intuition was there were >> enough new features that the volume of discussion to do that would be a >> poor cost/benefit compared to the "lazy consensus, revert" approach. >> >> >> >> So if I actually do the work required to have an opinion ;): >> >> >> https://docs.oracle.com/en/java/javase/21/language/java-language-changes-release.html#GUID-6459681C-6881-45D8-B0DB-395D1BD6DB9B >> >> >> >> JDK21: >> >> - Record Patterns >> >> - Pattern Matching for switch Expressions and Statements >> >> - String Templates >> >> - Unnamed Patterns and Variables >> >> - Unnamed Classes and Instance Main Methods >> >> JDK17: >> >> - Sealed Classes >> >> JDK16: >> >> - Pattern Matching for instanceof >> >> JDK15: >> >> - Text Blocks >> >> JDK14: >> >> - Switch Expressions >> >> JDK11: >> >> - Local Variable Type Inference (test only, not prod code is where we >> landed) >> >> >> >> Assuming we just lazily evaluate and deal with new features as people >> actually care about them and seeing them add value, a simple "[DISCUSS] I'm >> thinking about using new language feature X; any objection?" lazy consensus >> that we then dumped onto a wiki article / code style page as "stuff we're >> good to use" would probably be fine? >> >> >> >> >> >> On Fri, May 9, 2025, at 7:58 AM, Benedict wrote: >> >> >> >> >> >> I think it doesn’t cost us much to briefly discuss new language >> features before using them. Lambdas, Streams and var all have problems - >> and even with the guidance we publish some are still misused. >> >> >> >> The flow scoping improvement to instanceof seems obviously good though. >> >> >> >> >> >> On 9 May 2025, at 12:30, Josh McKenzie <jmcken...@apache.org> wrote: >> >> >> >> >> >> For new feature work on trunk, targeting the highest supported >> language level featureset (jdk17 right now, jdk21 within the next couple of >> weeks) makes sense to me. For bugfixing, targeting the oldest supported GA >> branch and the highest language level that works there would allow maximum >> flexibility with minimal re-implementation. >> >> >> >> If anyone has any misgivings with certain features (i.e. the debate >> around usage of "var") they can bring it up on the dev ML and we can >> adjust, but otherwise I'd prefer to see us have more modern evolving >> options on how contributors engage rather than less. >> >> >> >> On Fri, May 9, 2025, at 1:56 AM, Vivekanand Koya wrote: >> >> >> >> Hello, >> >> >> >> I want to understand the community's thoughts on using newer features >> (post JDK11) in upcoming releases in Cassandra. An example is flow scoping >> instead of explicitly casting types with instanceOf: >> https://openjdk.org/jeps/395. I want your thoughts on JDK requirements >> for the main Cassandra repository, Accord, and Sidecar. >> >> >> >> Much appreciated. >> >> Thanks, >> >> Vivekanand K. >> >> >> >> >> >> >> >> >> >> >> >> >> >
