That is odd. I thought maybe lower version had a bigger custom cache or some other setting missed in the upgrade.
On Mon, 14 Sep 2020, 23:00 Nicolai Lune Vest, <nicolai.v...@lancom.de> wrote: > While cache configuration stays the same, cache hit rate for both, the > chunk cache and the key cache are worse (but still ok) after the update. > You can see the change in the attached screenshot (update was performed at > September the 7th ~4pm). > > @Sagar Any specific reason you are suspecting the cache? > > > > -----"Sagar Jambhulkar" <sagar.jambhul...@gmail.com> schrieb: ----- > An: user@cassandra.apache.org > Von: "Sagar Jambhulkar" <sagar.jambhul...@gmail.com> > Datum: 14.09.2020 16:25 > Betreff: Re: Increased read latency with Cassandra >= 3.11.7 > > > Maybe compare the cache size see if anything different in two versions? > > > On Mon, 14 Sep 2020, 19:21 Nicolai Lune Vest, <nicolai.v...@lancom.de> > wrote: > > > Dear Cassandra community, > > after upgrading my Cassandra nodes from version 3.11.6 to either 3.11.7 or > 3.11.8 I experience a significant increase in read latency. > With 3.11.6 average read latency is ~0.35 ms. With 3.11.7 average read > latency increases to ~2.9 ms, almost 10 times worse! This behavior applies > to all my environments, testing and productive. > > I do also observe that the "bloom-filter false positive rate" and "SSTable > reads" increases significantly with version >= 3.11.7 > > I'm wondering if someone experienced the same problem when updating > Cassandra from 3.11.6 to either 3.11.7 or 3.11.8 and can help me out. > > I already tried nodetool scrub, sstablescrub, manual compaction, and > repair on selected tables without impact. When downgrading back to 3.11.6 > read latency recovers immediately. > > My update routine is very simple. I'm just stopping the service, install > the new version (using apt), and start the service again. One node after > the other. As coming from 3.11.6 updating to 3.11.7 (or 3.11.8) is just a > patch update and I expect this routine should do well, but maybe I'm > missing some important steps here. > > I can provide more information about my system or configuration if > required. > > Appreciate your support! > > Kind regards > Nico > > > > > > > > LANCOM Systems GmbH > Adenauerstr. 20 / B2 > 52146 Würselen > Deutschland > > Tel: +49 2405 49936-0 > Fax: +49 2405 49936-99 > > Web: https://www.lancom-systems.de > > > > Geschäftsführer: Ralf Koenzen, Stefan Herrlich > Sitz der Gesellschaft: Aachen, Amtsgericht Aachen, HRB 16976 > > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > For additional commands, e-mail: user-h...@cassandra.apache.org
