Given the JIRA in question, if you want to override the timeout to lower it, then the worst case if not supported yet is that you get the default timeout. So this then makes me wonder "is there a way to add metadata to a message which is ignored if unknown" (aka forward compatibility). Skimming the frame code i see we have
boolean isCustomPayload = frame.header.flags.contains(Frame.Header.Flag.CUSTOM_PAYLOAD); boolean hasWarning = frame.header.flags.contains(Frame.Header.Flag.WARNING); UUID tracingId = isRequest || !isTracing ? null : CBUtil.readUUID(frame.body); List<String> warnings = isRequest || !hasWarning ? null : CBUtil.readStringList(frame.body); Map<String, ByteBuffer> customPayload = !isCustomPayload ? null : CBUtil.readBytesMap(frame.body); This makes me wonder if we could picky back off that for new features, that way older servers just ignore them. I have no idea of the negatives of customPayload (other than strings are more bytes for messages, evolution may be based off key names so annoying, etc.), but tags which are ignored sounds promising On Tue, Feb 18, 2020 at 1:53 PM Jeff Jirsa <jji...@gmail.com> wrote: > A few notes: > > - Protocol changes add work to the rest of the ecosystem. Drivers have to > update, etc. > - Nobody expects protocol changes in minors, though it's less of a concern > if we don't deprecate out the older version. E.g. if 4.0 launches with > protocol v4 and protocol v5, and then 4.0.2 adds protocol v6, do we > deprecate out v4? If yes, you potentially break clients that only supported > v3 and v4 in a minor version upgrade, which is unexpected. If not, how many > protocol versions are you willing to support at any given time? > - Having protocol changes introduces risk. Paging behavior across protocol > versions is the site of a number of different bugs recently. > > > On Tue, Feb 18, 2020 at 1:46 PM Tolbert, Andrew <x...@andrewtolbert.com> > wrote: > > > I don't know the technical answer, but I suspect two motivations for > > doing new protocol versions in major releases could include: > > > > * protocol changes can be tied to feature changes that typically come > > in a major release. > > * protocol changes should be as infrequent as major releases. Each > > new protocol version is another thing in the test matrix that needs to > > be tested. > > > > That last point can make it hard to get new changes in. If something > > doesn't make the upcoming protocol version, it might be years before > > another one, but I also think it's worth it to do this infrequently as > > it makes maintaining client and server code easier if there are less > > protocol versions to worry about. > > > > On the client-side, libraries themselves should be avoiding making > > Cassandra version checks when detecting capabilities. There are a few > > exceptions, such as system table parsing for schema & peers, > > but those aren't related to the protocol. > > > > Thanks, > > Andy > > > > > > > > > > > > On Tue, Feb 18, 2020 at 1:22 PM Nate McCall <zznat...@gmail.com> wrote: > > > > > > [Moving to new message thread] > > > > > > Thanks for bringing this up, Jordan. > > > > > > IIRC, this was more a convention than a technical reason. Though I > could > > be > > > completely misremembering this. > > > > > > ---------- Forwarded message --------- > > > From: Jordan West <jorda...@gmail.com> > > > Date: Wed, Feb 19, 2020 at 10:13 AM > > > Subject: Re: 20200217 4.0 Status Update > > > To: <dev@cassandra.apache.org> > > > > > > > > > On Mon, Feb 17, 2020 at 12:52 PM Jeff Jirsa <jji...@gmail.com> wrote: > > > > > > > > > > > beyond the client proto change being painful for anything other than > > major > > > > releases > > > > > > > > > > > This came up during the community meeting today and I wanted to bring a > > > question about it to the list: could someone who is *very* familiar > with > > > the client proto share w/ the list why changing the proto in anything > > other > > > than a major release is so difficult? I hear this a lot and it seems to > > be > > > fact. So that all of us don't have to go read the code, a brief summary > > > would be super helpful. Or if there is a ticket that already covers > this > > > even better! I'd also be curious if there have ever been any thoughts > to > > > address it as it seems to be a consistent hurdle during the release > cycle > > > and one that tends to further increase scope. > > > > > > Thanks, > > > Jordan > > > > > > > > > > > > > > > > On Feb 17, 2020, at 12:43 PM, Jon Meredith <jmeredit...@gmail.com> > > > > wrote: > > > > > > > > > > My turn to give an update on 4.0 status. The 4.0 board created by > > Josh > > > > can > > > > > be found at > > > > > > > > > > > > > > > > https://issues.apache.org/jira/secure/RapidBoard.jspa?rapidView=355. > > > > > > > > > > > > > > > We have 94 unresolved tickets marked against the 4.0 release. [1] > > > > > > > > > > > > > > > Things seem to have settled into a phase of working to resolve > > issues, > > > > with > > > > > few new issues added. > > > > > > > > > > > > > > > 2 new tickets opened (that are marked against 4.0) > > > > > > > > > > 11 tickets closed (including one of the newly opened ones) > > > > > > > > > > 39 tickets received updates to JIRA of some kind in the last week > > > > > > > > > > > > > > > Cumulative flow over the last couple of weeks shows todo reducing > and > > > > done > > > > > increasing as it should as we continue to close out work for the > > > release. > > > > > > > > > > > > > > > > > > > > > > > > > https://issues.apache.org/jira/secure/RapidBoard.jspa?rapidView=355&projectKey=CASSANDRA&view=reporting&chart=cumulativeFlowDiagram&swimlane=939&swimlane=936&swimlane=931&column=1505&column=1506&column=1514&column=1509&column=1512&column=1507&days=14 > > > > > > > > > > > > > > > Notables > > > > > > > > > > - Python 3 support for cqlsh has been committed (thank you all who > > > > > persevered on this) > > > > > > > > > > - Some activity on Windows support - perhaps not dead yet. > > > > > > > > > > - Lots of movement on documentation > > > > > > > > > > - Lots of activity on flaky tests. > > > > > > > > > > - Oldest ticket with a patch award goes to CASSANDRA-2848 > > > > > > > > > > > > > > > There are 18 tickets marked as patch available (easy access from > the > > > > > Dashboard [2], apologies if they're already picked up for review) > > > > > > > > > > > > > > > CASSANDRA-15567 Allow EXTRA_CLASSPATH to work in tarball/source > > > > > installations > > > > > > > > > > CASSANDRA-15553 Preview repair should include sstables from > finalized > > > > > incremental repair sessions > > > > > > > > > > CASSANDRA-15550 Fix flaky test > > > > > org.apache.cassandra.streaming.StreamTransferTaskTest > > > > > testFailSessionDuringTransferShouldNotReleaseReferences > > > > > > > > > > CASSANDRA-15488/CASSANDRA-15353 Configuration file > > > > > > > > > > CASSANDRA-15484/CASSANDRA-15353 Read Repair > > > > > > > > > > CASSANDRA-15482/CASSANDRA-15353 Guarantees > > > > > > > > > > CASSANDRA-15481/CASSANDRA-15353 Data Modeling > > > > > > > > > > CASSANDRA-15393/CASSANDRA-15387 Add byte array backed cells > > > > > > > > > > CASSANDRA-15391/CASSANDRA-15387 Reduce heap footprint of commonly > > > > allocated > > > > > objects > > > > > > > > > > CASSANDRA-15367 Memtable memory allocations may deadlock > > > > > > > > > > CASSANDRA-15308 Fix flakey testAcquireReleaseOutbound - > > > > > org.apache.cassandra.net.ConnectionTest > > > > > > > > > > CASSANDRA-1530 5Fix multi DC nodetool status output > > > > > > > > > > CASSANDRA-14973 Bring v5 driver out of beta, introduce v6 before > 4.0 > > > > > release is cut > > > > > > > > > > CASSANDRA-14939 fix some operational holes in incremental repair > > > > > > > > > > CASSANDRA-14904 SSTableloader doesn't understand listening for CQL > > > > > connections on multiple ports > > > > > > > > > > CASSANDRA-14842 SSL connection problems when upgrading to 4.0 when > > > > > upgrading from 3.0.x > > > > > > > > > > CASSANDRA-14761 Rename speculative_retry to match > > > additional_write_policy > > > > > > > > > > CASSANDRA-2848 Make the Client API support passing down timeouts > > > > > > > > > > > > > > > *LHF / Failing Tests*: We have 7 unassigned test failures that are > > all > > > > > > > > > > great candidates to pick up and get involved in: > > > > > > > > > > > > > > > > > > > > https://issues.apache.org/jira/secure/RapidBoard.jspa?rapidView=355&projectKey=CASSANDRA&quickFilter=1660&quickFilter=1661&quickFilter=1658 > > > > > > > > > > > > > > > Thanks again to everybody for all the contributions. It's really > > good to > > > > > see the open issue count start dropping. > > > > > > > > > > > > > > > Feedback on whether this information is useful and how it can be > > > improved > > > > > is both welcome and appreciated. > > > > > > > > > > > > > > > Cheers, Jon > > > > > > > > > > > > > > > [1] Unresolved 4.0 tickets > > > > > > > > > > > > > > > https://issues.apache.org/jira/browse/CASSANDRA-15567?filter=12347782&jql=project%20%3D%20cassandra%20AND%20fixversion%20in%20(4.0%2C%204.0.0%2C%204.0-alpha%2C%204.0-beta)%20AND%20status%20!%3D%20Resolved > > > > > > > > > > [2] Patch Available > > > > > > > > > > > > https://issues.apache.org/jira/secure/Dashboard.jspa?selectPageId=12334910 > > > > > > > > --------------------------------------------------------------------- > > > > 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 > > > > >
