We’re seeing evidence across our fleet that AWS has rolled something out in the last 24 hours that has significantly reduce the performance impacts - back pretty close to pre-patch levels. Yet to see if the impacts come back with o/s patching on top of the improved hypervisor.
Cheers Ben On Thu, 11 Jan 2018 at 05:32 Jon Haddad <j...@jonhaddad.com> wrote: > For what it’s worth, we (TLP) just posted some results comparing pre and > post meltdown statistics: > http://thelastpickle.com/blog/2018/01/10/meltdown-impact-on-latency.html > > > On Jan 10, 2018, at 1:57 AM, Steinmaurer, Thomas < > thomas.steinmau...@dynatrace.com> wrote: > > m4.xlarge do have PCID to my knowledge, but possibly we need a rather new > kernel 4.14. But I fail to see how this could help anyway, cause this looks > highly Amazon Hypervisor patch related and we do not 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 - 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 AM, Steinmaurer, Thomas < > thomas.steinmau...@dynatrace.com> wrote: > > Quick follow up. > > Others in AWS reporting/seeing something similar, e.g.: > https://twitter.com/BenBromhead/status/950245250504601600 > > So, while we have seen an relative CPU increase of ~ 50% since Jan 4, > 2018, we now also have applied a kernel update at OS/VM level on a single > node (loadtest and not production though), thus more or less double patched > now. Additional CPU impact by OS/VM level kernel patching is more or less > negligible, 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 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, 2018, > most likely correlating with Amazon finished patching the underlying > Hypervisor infrastructure … > > Anybody else seeing a similar CPU increase? > > Thanks, > Thomas > > The contents of this e-mail are intended for the named addressee only. It > contains information that may be confidential. Unless you are the named > addressee or an authorized designee, you may not copy or use it, or > disclose it to anyone else. If you received it in error please notify us > immediately and then destroy it. Dynatrace Austria GmbH (registration > number FN 91482h) is a company registered in Linz whose registered office > is at 4040 Linz, Austria, Freistädterstraße 313 > <https://maps.google.com/?q=4040+Linz,+Austria,+Freist%C3%A4dterstra%C3%9Fe+313&entry=gmail&source=g> > The contents of this e-mail are intended for the named addressee only. It > contains information that may be confidential. Unless you are the named > addressee or an authorized designee, you may not copy or use it, or > disclose it to anyone else. If you received it in error please notify us > immediately and then destroy it. Dynatrace Austria GmbH (registration > number FN 91482h) is a company registered in Linz whose registered office > is at 4040 Linz, Austria, Freistädterstraße 313 > <https://maps.google.com/?q=4040+Linz,+Austria,+Freist%C3%A4dterstra%C3%9Fe+313&entry=gmail&source=g> > > > The contents of this e-mail are intended for the named addressee only. It > contains information that may be confidential. Unless you are the named > addressee or an authorized designee, you may not copy or use it, or > disclose it to anyone else. If you received it in error please notify us > immediately and then destroy it. Dynatrace Austria GmbH (registration > number FN 91482h) is a company registered in Linz whose registered office > is at 4040 Linz, Austria, Freistädterstraße 313 > <https://maps.google.com/?q=4040+Linz,+Austria,+Freist%C3%A4dterstra%C3%9Fe+313&entry=gmail&source=g> > > > -- *Ben Slater* *Chief Product Officer <https://www.instaclustr.com/>* <https://www.facebook.com/instaclustr> <https://twitter.com/instaclustr> <https://www.linkedin.com/company/instaclustr> Read our latest technical blog posts here <https://www.instaclustr.com/blog/>. This email has been sent on behalf of Instaclustr Pty. Limited (Australia) and Instaclustr Inc (USA). This email and any attachments may contain confidential and legally privileged information. If you are not the intended recipient, do not copy or disclose its content, but please reply to this email immediately and highlight the error to the sender and then immediately delete the message.
