Hi, Seeing too many -'s for changing the representation and essentially no +1s so I submitted a patch for just changing the default. I could use a reviewer for https://issues.apache.org/jira/browse/CASSANDRA-13241
I created https://issues.apache.org/jira/browse/CASSANDRA-14857 "Use a more space efficient representation for compressed chunk offsets" for post 4.0. Regards, Ariel On Tue, Oct 23, 2018, at 11:46 AM, Ariel Weisberg wrote: > Hi, > > To summarize who we have heard from so far > > WRT to changing just the default: > > +1: > Jon Haddadd > Ben Bromhead > Alain Rodriguez > Sankalp Kohli (not explicit) > > -0: > Sylvaine Lebresne > Jeff Jirsa > > Not sure: > Kurt Greaves > Joshua Mckenzie > Benedict Elliot Smith > > WRT to change the representation: > > +1: > There are only conditional +1s at this point > > -0: > Sylvaine Lebresne > > -.5: > Jeff Jirsa > > This > (https://github.com/aweisberg/cassandra/commit/a9ae85daa3ede092b9a1cf84879fb1a9f25b9dce) > > is a rough cut of the change for the representation. It needs better > naming, unit tests, javadoc etc. but it does implement the change. > > Ariel > On Fri, Oct 19, 2018, at 3:42 PM, Jonathan Haddad wrote: > > Sorry, to be clear - I'm +1 on changing the configuration default, but I > > think changing the compression in memory representations warrants further > > discussion and investigation before making a case for or against it yet. > > An optimization that reduces in memory cost by over 50% sounds pretty good > > and we never were really explicit that those sort of optimizations would be > > excluded after our feature freeze. I don't think they should necessarily > > be excluded at this time, but it depends on the size and risk of the patch. > > > > On Sat, Oct 20, 2018 at 8:38 AM Jonathan Haddad <j...@jonhaddad.com> wrote: > > > > > I think we should try to do the right thing for the most people that we > > > can. The number of folks impacted by 64KB is huge. I've worked on a lot > > > of clusters created by a lot of different teams, going from brand new to > > > pretty damn knowledgeable. I can't think of a single time over the last 2 > > > years that I've seen a cluster use non-default settings for compression. > > > With only a handful of exceptions, I've lowered the chunk size > > > considerably > > > (usually to 4 or 8K) and the impact has always been very noticeable, > > > frequently resulting in hardware reduction and cost savings. Of all the > > > poorly chosen defaults we have, this is one of the biggest offenders that > > > I > > > see. There's a good reason ScyllaDB claims they're so much faster than > > > Cassandra - we ship a DB that performs poorly for 90+% of teams because we > > > ship for a specific use case, not a general one (time series on memory > > > constrained boxes being the specific use case) > > > > > > This doesn't impact existing tables, just new ones. More and more teams > > > are using Cassandra as a general purpose database, we should acknowledge > > > that adjusting our defaults accordingly. Yes, we use a little bit more > > > memory on new tables if we just change this setting, and what we get out > > > of > > > it is a massive performance win. > > > > > > I'm +1 on the change as well. > > > > > > > > > > > > On Sat, Oct 20, 2018 at 4:21 AM Sankalp Kohli <kohlisank...@gmail.com> > > > wrote: > > > > > >> (We should definitely harden the definition for freeze in a separate > > >> thread) > > >> > > >> My thinking is that this is the best time to do this change as we have > > >> not even cut alpha or beta. All the people involved in the test will > > >> definitely be testing it again when we have these releases. > > >> > > >> > On Oct 19, 2018, at 8:00 AM, Michael Shuler <mich...@pbandjelly.org> > > >> wrote: > > >> > > > >> >> On 10/19/18 9:16 AM, Joshua McKenzie wrote: > > >> >> > > >> >> At the risk of hijacking this thread, when are we going to transition > > >> from > > >> >> "no new features, change whatever else you want including refactoring > > >> and > > >> >> changing years-old defaults" to "ok, we think we have something that's > > >> >> stable, time to start testing"? > > >> > > > >> > Creating a cassandra-4.0 branch would allow trunk to, for instance, get > > >> > a default config value change commit and get more testing. We might > > >> > forget again, from what I understand of Benedict's last comment :) > > >> > > > >> > -- > > >> > Michael > > >> > > > >> > --------------------------------------------------------------------- > > >> > 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 > > >> > > >> > > > > > > -- > > > Jon Haddad > > > http://www.rustyrazorblade.com > > > twitter: rustyrazorblade > > > > > > > > > -- > > Jon Haddad > > http://www.rustyrazorblade.com > > twitter: rustyrazorblade > > --------------------------------------------------------------------- > 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
