Amy's Guide. Still getting it done after all these years. Legendary. On Tue, Sep 20, 2022 at 6:05 AM Jeff Jirsa <jji...@gmail.com> wrote:
> Beyond this there are two decent tuning sets, but relatively dated at this > point > > Cassandra-8150 proposed a number of changes to defaults based on how it > had been tuned at a specific large (competent) user: > > ASF JIRA > <https://issues.apache.org/jira/plugins/servlet/mobile#issue/CASSANDRA-8150> > issues.apache.org > <https://issues.apache.org/jira/plugins/servlet/mobile#issue/CASSANDRA-8150> > [image: favicon.ico] > <https://issues.apache.org/jira/plugins/servlet/mobile#issue/CASSANDRA-8150> > <https://issues.apache.org/jira/plugins/servlet/mobile#issue/CASSANDRA-8150> > > Any Tobey wrote this guide around the 2.0/2.1 era, so it assumes things > like jdk8 / CMS, but still has more rigor than most other guides you’ll > find elsewhere and may help identify what’s going on even if the specific > tuning isn’t super relevant in all cases: > > Amy's Cassandra 2.1 tuning guide : Amy Writes > <https://tobert.github.io/pages/als-cassandra-21-tuning-guide.html> > tobert.github.io > <https://tobert.github.io/pages/als-cassandra-21-tuning-guide.html> > [image: favicon.ico] > <https://tobert.github.io/pages/als-cassandra-21-tuning-guide.html> > <https://tobert.github.io/pages/als-cassandra-21-tuning-guide.html> > > > > On Sep 20, 2022, at 5:27 AM, Michail Kotsiouros via user < > user@cassandra.apache.org> wrote: > > > > Hello community, > > BTW I am using Cassandra 3.11.4. From your comments, I understand that a > CPU spike and maybe a long GC may be expected at the snapshot creation > under specific circumstances. I will monitor the resources during snapshot > creation. I will come back with more news. > > > > Thanks a lot for your valuable input. > > > > BR > > MK > > *From:* Jeff Jirsa <jji...@gmail.com> > *Sent:* Monday, September 19, 2022 20:06 > *To:* user@cassandra.apache.org; Michail Kotsiouros < > michail.kotsiou...@ericsson.com> > *Subject:* Re: Cassandra GC tuning > > > > https://issues.apache.org/jira/browse/CASSANDRA-13019 is in 4.0, you may > find that tuning those thresholds > > > > On Mon, Sep 19, 2022 at 9:50 AM Jeff Jirsa <jji...@gmail.com> wrote: > > Snapshots are probably actually caused by a spike in disk IO and disk > latency, not GC (you'll see longer STW pauses as you get to a safepoint if > that disk is hanging). This is especially problematic on SATA SSDs, or nVME > SSDs with poor IO scheduler tuning. There's a patch somewhere to throttle > hardlinks to try to mitigate this. > > > > On Mon, Sep 19, 2022 at 3:45 AM Michail Kotsiouros via user < > user@cassandra.apache.org> wrote: > > Hello community, > > I observe some GC pauses while trying to create snapshots of a keyspace. > The GC pauses as such are not long, even though they are reported in logs. > The problem is the CPU utilization which affects other applications > deployed in my server. > > Do you have any articles or recommendations about tuning GC in Cassandra? > > > > Thank you in advance. > > BR > > MK > >
favicon.ico
Description: Binary data
favicon.ico
Description: Binary data
