Got it. Thanks On Mon, Oct 2, 2017 at 4:54 AM, Justin Cameron <jus...@instaclustr.com> wrote:
> Hi Avi, > > Actually, in Thomas' example you would need an additional 100G of free > disk space to complete the compaction, in the worst-case situation (the > worst-case would be that neither input SSTable contains any overlapping > data or tombstones, therefore the output SSTable would also be roughly > 100G). > > STCS progressively compacts SSTables of similar size together, with the > output being a single SSTable containing the data of the input SSTables. > > Eventually you may end up with some very large SSTables that combined will > take up 50% of your total disk space. In order to compact those SSTables > together, STCS requires an equal amount of free disk space, which would be > the other (unused) 50% of your total disk space. > > Cheers, > Justin > > On Mon, 2 Oct 2017 at 12:42 Avi Levi <a...@indeni.com> wrote: > >> Hi Thomas , >> So IIUC in this case you should leave at least 50G for compaction (half >> of the sstables size). Is that makes sense? >> Cheers >> Avi >> >> >> On Oct 1, 2017 11:39 AM, "Steinmaurer, Thomas" < >> thomas.steinmau...@dynatrace.com> wrote: >> >> Hi, >> >> >> >> half of free space does not make sense. Imagine your SSTables need 100G >> space and you have 20G free disk. Compaction won’t be able to do its job >> with 10G. >> >> >> >> Half free of total disk makes more sense and is what you need for a major >> compaction worst case. >> >> >> >> Thomas >> >> >> >> *From:* Peng Xiao [mailto:2535...@qq.com] >> *Sent:* Samstag, 30. September 2017 10:21 >> *To:* user <user@cassandra.apache.org> >> *Subject:* space left for compaction >> >> >> >> Dear All, >> >> >> >> As for STCS,datastax suggest us to keep half of the free space for >> compaction,this is not strict,could anyone advise how many space should we >> left for one node? >> >> >> >> Thanks, >> >> Peng Xiao >> 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, Freist >> <https://maps.google.com/?q=4040+Linz,+Austria,+Freist%C3%A4dterstra%C3%9Fe+313&entry=gmail&source=g> >> ädterstra >> <https://maps.google.com/?q=4040+Linz,+Austria,+Freist%C3%A4dterstra%C3%9Fe+313&entry=gmail&source=g> >> ße 313 >> <https://maps.google.com/?q=4040+Linz,+Austria,+Freist%C3%A4dterstra%C3%9Fe+313&entry=gmail&source=g> >> >> >> -- > > > *Justin Cameron*Senior Software Engineer > > > <https://www.instaclustr.com/> > > > 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. >
