RE: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

. Thomas From: Ben Slater [mailto:ben.sla...@instaclustr.com] Sent: Freitag, 12. Jänner 2018 23:37 To: user@cassandra.apache.org Subject: Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra? We’re seeing evidence across our fleet that AWS has rolled something out in the last 24 hours

RE: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

g as well: https://blog.appoptics.com/visualizing-meltdown-aws/ Regards, Thomas *From:* Ben Slater [mailto:ben.sla...@instaclustr.com] *Sent:* Freitag, 12. Jänner 2018 23:37 *To:* user@cassandra.apache.org *Subject:* Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra? We’re seeing evi

RE: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

om<mailto:thomas.steinmau...@dynatrace.com>] Sent: Freitag, 05. Jänner 2018 12:09 To: user@cassandra.apache.org<mailto:user@cassandra.apache.org> Subject: Meltdown/Spectre Linux patch - Performance impact on Cassandra? Hello, has anybody already some experience/results if a patched

Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

have the production > instances patched at OS/VM level (yet). > > Thomas > > *From:* Dor Laor [mailto:d...@scylladb.com <d...@scylladb.com>] > *Sent:* Dienstag, 09. Jänner 2018 19:30 > *To:* user@cassandra.apache.org > *Subject:* Re: Meltdown/Spectre Linux patch - Perfor

Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

ve the production > instances patched at OS/VM level (yet). <> > > Thomas > > From: Dor Laor [mailto:d...@scylladb.com] > Sent: Dienstag, 09. Jänner 2018 19:30 > To: user@cassandra.apache.org > Subject: Re: Meltdown/Spectre Linux patch - Performance impact on

RE: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

[mailto:d...@scylladb.com] Sent: Dienstag, 09. Jänner 2018 19:30 To: user@cassandra.apache.org Subject: Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra? Make sure you pick instances with PCID cpu capability, their TLB overhead flush overhead is much smaller On Tue, Jan 9, 2018 at 2:04

Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

ible, so looks highly Hypervisor related. >> >> >> >> Regards, >> >> Thomas >> >> >> >> From: Steinmaurer, Thomas [mailto:thomas.steinmau...@dynatrace.com] >> Sent: Freitag, 05. Jänner 2018 12:09 >> To: user@cassandra.apac

Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

t;> >> Regards, >> >> Thomas >> >> >> >> *From:* Steinmaurer, Thomas [mailto:thomas.steinmau...@dynatrace.com] >> *Sent:* Freitag, 05. Jänner 2018 12:09 >> *To:* user@cassandra.apache.org >> *Subject:* Meltdown/Spectre Linux patch - Per

Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

egligible, > so looks highly Hypervisor related. > > > > Regards, > > Thomas > > > > *From:* Steinmaurer, Thomas [mailto:thomas.steinmau...@dynatrace.com] > *Sent:* Freitag, 05. Jänner 2018 12:09 > *To:* user@cassandra.apache.org > *Subject:* Meltdown/Spectre

Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

down/Spectre Linux patch - Performance impact on Cassandra? Hello,  has anybody already some experience/results if a patched Linux kernel regarding Meltdown/Spectre is affecting performance of Cassandra negatively? In production, all nodes running in AWS with m4.xlarge, we see up to a 50% relati

Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

*Sent:* Freitag, 05. Jänner 2018 12:09 > *To:* user@cassandra.apache.org > *Subject:* Meltdown/Spectre Linux patch - Performance impact on Cassandra? > > > > Hello, > > > > has anybody already some experience/results if a patched Linux kernel > regarding Meltdown/Spe

RE: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

12:09 To: user@cassandra.apache.org Subject: Meltdown/Spectre Linux patch - Performance impact on Cassandra? Hello, has anybody already some experience/results if a patched Linux kernel regarding Meltdown/Spectre is affecting performance of Cassandra negatively? In production, all nodes running

Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

Thanks for the insight, Romain, and providing those numbers. Looking forward to others posting their stats here. We are running up some tests and will share when available. Cheers! On Sat, Jan 6, 2018 at 3:44 AM, Romain Hardouin wrote: > Hi, > > We also noticed an

Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

Hi, We also noticed an increase of CPU - both system and user - on our c3.4xlarge fleet. So far it's really visible with max(%user) and especially max(%system), it has doubled!I graphed a ratio "write/s / %system", it's interesting to see how the value dropped yesterday, you can see it here:

Re: Meltdown/Spectre Linux patch - Performance impact on Cassandra?

Hi Thomas, No clue about AWS, and it is of course highly dependent on hardware, but on CentOS 7 on bare metal, the patched kernel (kernel-3.10.0-693.11.6.el7.x86_64) seems to have a roughly 50% CPU increase compared to an unpatched kernel (kernel-3.10.0-693.11.1.el7.x86_64). On a happier note,

Meltdown/Spectre Linux patch - Performance impact on Cassandra?

Hello, has anybody already some experience/results if a patched Linux kernel regarding Meltdown/Spectre is affecting performance of Cassandra negatively? In production, all nodes running in AWS with m4.xlarge, we see up to a 50% relative (e.g. AVG CPU from 40% => 60%) CPU increase since Jan 4,