Hi guys, Have you looked wiredtiger? It has LevelDB compatibility API and also has b-tree. http://source.wiredtiger.com/2.4.1/index.html About their benchmark, wiredtiger performance is better than LevelDB at all io pattern. https://github.com/wiredtiger/wiredtiger/wiki/LevelDB-Benchmark Regards, Satoru Funai ----- 元のメッセージ ----- > 差出人: "Xiaoxi Chen" <xiaoxi.chen@xxxxxxxxx> > 宛先: "Haomai Wang" <haomaiwang@xxxxxxxxx> > Cc: "Satoru Funai" <satoru.funai@xxxxxxxxx>, ceph-users@xxxxxxxx > 送信済み: 2014年12月1日, 月曜日 午後 11:26:56 > 件名: RE: LevelDB support status is still experimental on > Giant? > Range query is not that important in nowadays SSD----you can see very > high read random read IOPS in ssd spec, and getting higher day by > day.The key problem here is trying to exactly matching one > query(get/put) to one SSD IO(read/write), eliminate the read/write > amplification. We kind of believe OpenNvmKV may be the right > approach. > Back to the context of Ceph, can we find some use case of nowadays > key-value backend? We would like to learn from community what’s the > workload pattern if you wants a K-V backed Ceph? Or just have a try? > I think before we get a suitable DB backend ,we had better off to > optimize the key-value backend code to support specified kind of > load. > From: Haomai Wang [mailto:haomaiwang@xxxxxxxxx] > Sent: Monday, December 1, 2014 10:14 PM > To: Chen, Xiaoxi > Cc: Satoru Funai; ceph-users@xxxxxxxx > Subject: Re: LevelDB support status is still > experimental on Giant? > Exactly, I'm just looking forward a better DB backend suitable for > KeyValueStore. It maybe traditional B-tree design. > Kinetic original I think it was a good backend, but it doesn't > support range query :-( > On Mon, Dec 1, 2014 at 10:04 PM, Chen, Xiaoxi < xiaoxi.chen@xxxxxxxxx > > wrote: > > We have tested it for a while, basically it seems kind of stable > > but > > show terrible bad performance. > > > This is not the fault of Ceph , but levelDB, or more generally, all > > K-V storage with LSM design(RocksDB,etc), the LSM tree structure > > naturally introduce very large write amplification---- 10X to 20X > > when you have tens GB of data per OSD. So you can always see very > > bad sequential write performance (~200MB/s for a 12SSD setup), we > > can share more details on the performance meeting. > > > To this end, key-value backend with LevelDB is not useable for RBD > > usage, but maybe workable(not tested) in the LOSF cases ( tons of > > small objects stored via rados , k-v backend can prevent the FS > > metadata become the bottleneck) > > > From: ceph-users [mailto: ceph-users-bounces@xxxxxxxxxxxxxx ] On > > Behalf Of Haomai Wang > > > Sent: Monday, December 1, 2014 9:48 PM > > > To: Satoru Funai > > > Cc: ceph-users@xxxxxxxx > > > Subject: Re: LevelDB support status is still > > experimental on Giant? > > > Yeah, mainly used by test env. > > > On Mon, Dec 1, 2014 at 6:29 PM, Satoru Funai < > > satoru.funai@xxxxxxxxx > > > wrote: > > > > Hi guys, > > > > > > I'm interested in to use key/value store as a backend of Ceph > > > OSD. > > > > > > When firefly release, LevelDB support is mentioned as > > > experimental, > > > > > > is it same status on Giant release? > > > > > > Regards, > > > > > > Satoru Funai > > > > > > _______________________________________________ > > > > > > ceph-users mailing list > > > > > > ceph-users@xxxxxxxxxxxxxx > > > > > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > > -- > > > Best Regards, > > > Wheat > > -- > Best Regards, > Wheat _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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