Thanks a lot for your detailed explanation! I am very curious about the future development of Scylladb! Especially about mvs and lwt!
Am 11.03.2017 02:05 schrieb "Dor Laor" <d...@scylladb.com>: > On Fri, Mar 10, 2017 at 4:45 PM, Kant Kodali <k...@peernova.com> wrote: > >> http://performanceterracotta.blogspot.com/2012/09/numa-java.html >> http://docs.oracle.com/javase/7/docs/technotes/guides/vm/per >> formance-enhancements-7.html >> http://openjdk.java.net/jeps/163 >> >> > Java can exploit NUMA but it's not as a efficient as can be done in c++. > Andrea Arcangeli is the engineer behind Linux transparent huge pages(THP), > he > reported to me and the idea belongs to Avi. We did it for KVM's sake but > it was designed to any long running process like Cassandra. > However, the entire software stack should be aware. If you get a huge page > (2MB) > but keep in it only 1KB you waste lots of mem. On top of this, threads > need to > touch their data structures and they need to be well aligned, otherwise > the memory > page will bounce between the different cores. > With Cassandra it gets more complicated since there is a heap and off-heap > data. > > Do programmers really track their data alignment? I doubt it. > Do users run C* with the JVM numa options and the right Linux THP options? > Again, I doubt. > > Scylla on the other side is designed for NUMA. We have 2-level sharding. > The inner shards are transparent > to the user and are per-core (hyper thread). Such a shard access RAM only > within its numa node. Memory > is bonded to each thread/numa node. We have our own malloc allocator built > for this scheme. > > > >> If scyllaDB has efficient Secondary indexes, LWT and MV's then that is >> something. I would be glad to see how they perform. >> >> > MV will be in 1.8, we haven't measured performance yet. We did measure our > counter implementation > and it looks promising (4X better throughput and 4X better latency on a > 8-core machine). > The not-written yet LWT will kick-a** since our fully async engine is > ideal for the larger number > of round trips the LWT needs. > > This is with the Linux tcp stack, once we'll use our dpdk one, performance > will improve further ;) > > > >> >> On Fri, Mar 10, 2017 at 10:45 AM, Dor Laor <d...@scylladb.com> wrote: >> >>> Scylla isn't just about performance too. >>> >>> First, a disclaimer, I am a Scylla co-founder. I respect open source a >>> lot, >>> so you guys are welcome to shush me out of this thread. I only >>> participate >>> to provide value if I can (this is a thread about Scylla and our users >>> are >>> on our mailing list). >>> >>> Scylla is all about what Cassandra is plus: >>> - Efficient hardware utilization (scale-up, performance) >>> - Low tail latency >>> - Auto/dynamic tuning (no JVM tuning, we tune the OS ourselves, we have >>> cpu scheduler, >>> I/O userspace scheduler and more to come). >>> - SLA between compaction, repair, streaming and your r/w operations >>> >>> We started with a great foundation (C*) and wish to improve almost any >>> aspect of it. >>> Admittedly, we're way behind C* in terms of adoption. One need to start >>> somewhere. >>> However, users such as AppNexus run Scylla in production with 47 >>> physical nodes >>> across 5 datacenters and their VP estimate that C* would have at least >>> doubled the >>> size. So this is equal for a 100-node C* cluster. Since we have the same >>> gossip, murmur3 hash, >>> CQL, nothing stops us to scale to 1,000 nodes. Another user (Mogujie) >>> run 10s of TBs per node(!) >>> in production. >>> >>> Also, since we try to compare Scylla and C* in a fair way, we invested a >>> great deal of time >>> to run C*. I can say it's not simple at all. >>> Lastly, in a couple of months we'll reach parity in functionality with >>> C* (counters are in 1.7 as experimental, in 1.8 counters will be stable and >>> we'll have MV as experimental, LWT will be >>> in the summer). We hope to collaborate with the C* community with the >>> development of future >>> features. >>> >>> Dor >>> >>> >>> On Fri, Mar 10, 2017 at 10:19 AM, Jacques-Henri Berthemet < >>> jacques-henri.berthe...@genesys.com> wrote: >>> >>>> Cassandra is not about pure performance, there are many other DBs that >>>> are much faster than Cassandra. Cassandra strength is all about >>>> scalability, performance increases in a linear way as you add more nodes. >>>> During Cassandra summit 2014 Apple said they have a 10k node cluster. The >>>> usual limiting factor is your disk write speed and latency, I don’t see how >>>> C++ changes anything in this regard unless you can cache all your data in >>>> memory. >>>> >>>> >>>> >>>> I’d be curious to know how ScyllaDB performs with a 100+ nodes cluster >>>> with PBs of data compared to Cassandra. >>>> >>>> *--* >>>> >>>> *Jacques-Henri Berthemet* >>>> >>>> >>>> >>>> *From:* Rakesh Kumar [mailto:rakeshkumar...@outlook.com] >>>> *Sent:* vendredi 10 mars 2017 09:58 >>>> >>>> *To:* user@cassandra.apache.org >>>> *Subject:* Re: scylladb >>>> >>>> >>>> >>>> Cassanda vs Scylla is a valid comparison because they both are >>>> compatible. Scylla is a drop-in replacement for Cassandra. >>>> Is Aerospike a drop-in replacement for Cassandra? If yes, and only if >>>> yes, then the comparison is valid with Scylla. >>>> >>>> >>>> ------------------------------ >>>> >>>> *From:* Bhuvan Rawal <bhu1ra...@gmail.com> >>>> *To:* user@cassandra.apache.org >>>> *Sent:* Friday, March 10, 2017 11:59 AM >>>> *Subject:* Re: scylladb >>>> >>>> >>>> >>>> Agreed C++ gives an added advantage to talk to underlying hardware with >>>> better efficiency, it sound good but can a pice of code written in C++ give >>>> 1000% throughput than a Java app? Is TPC design 10X more performant than >>>> SEDA arch? >>>> >>>> >>>> >>>> And if C/C++ is indeed that fast how can Aerospike (which is itself >>>> written in C) claim to be 10X faster than Scylla here >>>> http://www.aerospike.com/benchmarks/scylladb-initial/ ? (Combining >>>> your's and aerospike's benchmarks it appears that Aerospike is 100X >>>> performant than C* - I highly doubt that!! ) >>>> >>>> >>>> >>>> For a moment lets forget about evaluating 2 different databases, one >>>> can observe 10X performance difference between a mistuned cassandra cluster >>>> and one thats tuned as per data model - there are so many Tunables in yaml >>>> as well as table configs. >>>> >>>> >>>> >>>> Idea is - in order to strengthen your claim, you need to provide >>>> complete system metrics (Disk, CPU, Network), the OPS increase starts to >>>> decay along with the configs used. Having plain ops per second and 99p >>>> latency is blackbox. >>>> >>>> >>>> >>>> Regards, >>>> >>>> Bhuvan >>>> >>>> >>>> >>>> On Fri, Mar 10, 2017 at 12:47 PM, Avi Kivity <a...@scylladb.com> wrote: >>>> >>>> ScyllaDB engineer here. >>>> >>>> C++ is really an enabling technology here. It is directly responsible >>>> for a small fraction of the gain by executing faster than Java. But it is >>>> indirectly responsible for the gain by allowing us direct control over >>>> memory and threading. Just as an example, Scylla starts by taking over >>>> almost all of the machine's memory, and dynamically assigning it to >>>> memtables, cache, and working memory needed to handle requests in flight. >>>> Memory is statically partitioned across cores, allowing us to exploit NUMA >>>> fully. You can't do these things in Java. >>>> >>>> I would say the major contributors to Scylla performance are: >>>> - thread-per-core design >>>> - replacement of the page cache with a row cache >>>> - careful attention to many small details, each contributing a little, >>>> but with a large overall impact >>>> >>>> While I'm here I can say that performance is not the only goal here, it >>>> is stable and predictable performance over varying loads and during >>>> maintenance operations like repair, without any special tuning. We measure >>>> the amount of CPU and I/O spent on foreground (user) and background >>>> (maintenance) tasks and divide them fairly. This work is not complete but >>>> already makes operating Scylla a lot simpler. >>>> >>>> >>>> >>>> On 03/10/2017 01:42 AM, Kant Kodali wrote: >>>> >>>> I dont think ScyllaDB performance is because of C++. The design >>>> decisions in scylladb are indeed different from Cassandra such as getting >>>> rid of SEDA and moving to TPC and so on. >>>> >>>> >>>> >>>> If someone thinks it is because of C++ then just show the benchmarks >>>> that proves it is indeed the C++ which gave 10X performance boost as >>>> ScyllaDB claims instead of stating it. >>>> >>>> >>>> >>>> >>>> >>>> On Thu, Mar 9, 2017 at 3:22 PM, Richard L. Burton III < >>>> mrbur...@gmail.com> wrote: >>>> >>>> They spend an enormous amount of time focusing on performance. You can >>>> expect them to continue on with their optimization and keep crushing it. >>>> >>>> >>>> >>>> P.S., I don't work for ScyllaDB. >>>> >>>> >>>> >>>> On Thu, Mar 9, 2017 at 6:02 PM, Rakesh Kumar < >>>> rakeshkumar...@outlook.com> wrote: >>>> >>>> In all of their presentation they keep harping on the fact that >>>> scylladb is written in C++ and does not carry the overhead of Java. Still >>>> the difference looks staggering. >>>> ______________________________ __________ >>>> From: daemeon reiydelle <daeme...@gmail.com> >>>> Sent: Thursday, March 9, 2017 14:21 >>>> To: user@cassandra.apache.org >>>> Subject: Re: scylladb >>>> >>>> The comparison is fair, and conservative. Did substantial performance >>>> comparisons for two clients, both results returned throughputs that were >>>> faster than the published comparisons (15x as I recall). At that time the >>>> client preferred to utilize a Cass COTS solution and use a caching solution >>>> for OLA compliance. >>>> >>>> >>>> ....... >>>> >>>> Daemeon C.M. Reiydelle >>>> USA (+1) 415.501.0198 <+1%20415-501-0198> >>>> London (+44) (0) 20 8144 9872 <+44%2020%208144%209872> >>>> >>>> On Thu, Mar 9, 2017 at 11:04 AM, Robin Verlangen >>>> <ro...@us2.nl<mailto:robin@us2 >>>> .nl <ro...@us2.nl>>> wrote: >>>> I was wondering how people feel about the comparison that's made here >>>> between Cassandra and ScyllaDB : http://www.scylladb.com/techno >>>> logy/ycsb-cassandra-scylla/#re sults-of-3-scylla-nodes-vs-30- >>>> cassandra-nodes >>>> <http://www.scylladb.com/technology/ycsb-cassandra-scylla/#results-of-3-scylla-nodes-vs-30-cassandra-nodes> >>>> >>>> They are claiming a 10x improvement, is that a fair comparison or maybe >>>> a somewhat coloured view of a (micro)benchmark in a specific setup? Any >>>> pros/cons known? >>>> >>>> Best regards, >>>> >>>> Robin Verlangen >>>> Chief Data Architect >>>> >>>> Disclaimer: The information contained in this message and attachments >>>> is intended solely for the attention and use of the named addressee and may >>>> be confidential. If you are not the intended recipient, you are reminded >>>> that the information remains the property of the sender. You must not use, >>>> disclose, distribute, copy, print or rely on this e-mail. If you have >>>> received this message in error, please contact the sender immediately and >>>> irrevocably delete this message and any copies. >>>> >>>> On Wed, Dec 16, 2015 at 11:52 AM, Carlos Rolo >>>> <r...@pythian.com<mailto:rolo@ >>>> pythian.com <r...@pythian.com>>> wrote: >>>> No rain at all! But I almost had it running last weekend, but stopped >>>> short of installing it. Let's see if this one is for real! >>>> >>>> Regards, >>>> >>>> Carlos Juzarte Rolo >>>> Cassandra Consultant >>>> >>>> Pythian - Love your data >>>> >>>> rolo@pythian | Twitter: @cjrolo | Linkedin: linkedin.com/in/carlosjuzarter >>>> olo <http://linkedin.com/in/carlosjuzarterolo><http://linkedin.com/in/car >>>> losjuzarterolo <http://linkedin.com/in/carlosjuzarterolo>> >>>> Mobile: +351 91 891 81 00 <+351%20918%20918%20100>< >>>> tel:+351%20918%20918%20100 <+351%20918%20918%20100>> | Tel: +1 613 565 >>>> 8696 x1649 <+1%20613-565-8696><tel:+1%20613-565-8696 >>>> <+1%20613-565-8696>> >>>> www.pythian.com<http://www.pyt hian.com/ <http://www.pythian.com/>> >>>> >>>> On Wed, Dec 16, 2015 at 12:38 AM, Dani Traphagen < >>>> dani.trapha...@datastax.com<m ailto:dani.traphagen@datastax. com >>>> <dani.trapha...@datastax.com>>> wrote: >>>> You'll be the first Carlos. >>>> >>>> [Inline image 1] >>>> >>>> Had any rain lately? Curious how this went, if so. >>>> >>>> On Thu, Nov 12, 2015 at 4:36 AM, Jack Krupansky < >>>> jack.krupan...@gmail.com<mail to:jack.krupan...@gmail.com>> wrote: >>>> I just did a Twitter search on scylladb and did not see any tweets >>>> about actual use, so far. >>>> >>>> >>>> -- Jack Krupansky >>>> >>>> On Wed, Nov 11, 2015 at 10:54 AM, Carlos Alonso <i...@mrcalonso.com >>>> <mailto:inf o...@mrcalonso.com <i...@mrcalonso.com>>> wrote: >>>> Any update about this? >>>> >>>> @Carlos Rolo, did you tried it? Thoughts? >>>> >>>> Carlos Alonso | Software Engineer | @calonso<https://twitter.com/c >>>> alonso <https://twitter.com/calonso>> >>>> >>>> On 5 November 2015 at 14:07, Carlos Rolo <r...@pythian.com<mailto:rolo@ >>>> pythian.com <r...@pythian.com>>> wrote: >>>> Something to do on a expected rainy weekend. Thanks for the information. >>>> >>>> Regards, >>>> >>>> Carlos Juzarte Rolo >>>> Cassandra Consultant >>>> >>>> Pythian - Love your data >>>> >>>> rolo@pythian | Twitter: @cjrolo | Linkedin: linkedin.com/in/carlosjuzarter >>>> olo <http://linkedin.com/in/carlosjuzarterolo><http://linkedin.com/in/car >>>> losjuzarterolo <http://linkedin.com/in/carlosjuzarterolo>> >>>> Mobile: +351 91 891 81 00 >>>> <+351%20918%20918%20100><tel:%2B351%2091%20891%2081% >>>> 2000 <%2B351%2091%20891%2081%25%202000>> | Tel: +1 613 565 8696 x1649 >>>> <+1%20613-565-8696><tel:%2B1%20613%20565%208 696%20x1649 >>>> <%2B1%20613%20565%208%20696%20x1649>> >>>> www.pythian.com<http://www.pyt hian.com/ <http://www.pythian.com/>> >>>> >>>> On Thu, Nov 5, 2015 at 12:07 PM, Dani Traphagen < >>>> dani.trapha...@datastax.com<m ailto:dani.traphagen@datastax. com >>>> <dani.trapha...@datastax.com>>> wrote: >>>> As of two days ago, they say they've got it @cjrolo. >>>> >>>> https://github.com/scylladb/sc ylla/wiki/RELEASE-Scylla-0.11- Beta >>>> <https://github.com/scylladb/scylla/wiki/RELEASE-Scylla-0.11-Beta> >>>> >>>> >>>> On Thursday, November 5, 2015, Carlos Rolo <r...@pythian.com<mailto:rolo@ >>>> pythian.com <r...@pythian.com>>> wrote: >>>> I will not try until multi-DC is implemented. More than an month has >>>> passed since I looked for it, so it could possibly be in place, if so I may >>>> take some time to test it. >>>> >>>> Regards, >>>> >>>> Carlos Juzarte Rolo >>>> Cassandra Consultant >>>> >>>> Pythian - Love your data >>>> >>>> rolo@pythian | Twitter: @cjrolo | Linkedin: linkedin.com/in/carlosjuzarter >>>> olo <http://linkedin.com/in/carlosjuzarterolo><http://linkedin.com/in/car >>>> losjuzarterolo <http://linkedin.com/in/carlosjuzarterolo>> >>>> Mobile: +351 91 891 81 00 >>>> <+351%20918%20918%20100><tel:%2B351%2091%20891%2081% >>>> 2000 <%2B351%2091%20891%2081%25%202000>> | Tel: +1 613 565 8696 x1649 >>>> <+1%20613-565-8696><tel:%2B1%20613%20565%208 696%20x1649 >>>> <%2B1%20613%20565%208%20696%20x1649>> >>>> www.pythian.com<http://www.pyt hian.com/ <http://www.pythian.com/>> >>>> >>>> On Thu, Nov 5, 2015 at 9:37 AM, Jon Haddad <jonathan.had...@gmail.com> >>>> wrote: >>>> Nope, no one I know. Let me know if you try it I'd love to hear your >>>> feedback. >>>> >>>> > On Nov 5, 2015, at 9:22 AM, tommaso barbugli <tbarbu...@gmail.com> >>>> wrote: >>>> > >>>> > Hi guys, >>>> > >>>> > did anyone already try Scylladb (yet another fastest NoSQL database >>>> in town) and has some thoughts/hands-on experience to share? >>>> > >>>> > Cheers, >>>> > Tommaso >>>> >>>> >>>> >>>> >>>> -- >>>> >>>> >>>> >>>> >>>> -- >>>> Sent from mobile -- apologizes for brevity or errors. >>>> >>>> >>>> >>>> -- >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> -- >>>> [datastax_logo.png]<http://www .datastax.com/ >>>> <http://www.datastax.com/>> >>>> >>>> DANI TRAPHAGEN >>>> >>>> Technical Enablement Lead | dani.trapha...@datastax.com<ma >>>> ilto:dani.traphagen@datastax.c >>>> om <dani.trapha...@datastax.com>> >>>> >>>> [twitter.png]<https://twitter. com/dtrapezoid >>>> <https://twitter.com/dtrapezoid>> [linkedin.png] >>>> <https://www.linkedin.com/pub/ >>>> dani-traphagen/31/93b/b85 >>>> <https://www.linkedin.com/pub/dani-traphagen/31/93b/b85>> >>>> [https://lh5.googleusercontent >>>> .com/WcFJcWZHKXnxu01V6zJIQapcG onoazqsv8O7_DtfhW-qbTRHxDjfX2o >>>> wDNmQhgojRx5Y4mLEc-KiAeeTJjT0V mKiiIld8UP86AgQPJDK2o6oC6BhTmu >>>> b4NLZ_MO9-E7l9Q >>>> <https://lh5.googleusercontent.com/WcFJcWZHKXnxu01V6zJIQapcGonoazqsv8O7_DtfhW-qbTRHxDjfX2owDNmQhgojRx5Y4mLEc-KiAeeTJjT0VmKiiIld8UP86AgQPJDK2o6oC6BhTmub4NLZ_MO9-E7l9Q>] >>>> <https://github.com/dtrapezoid > >>>> >>>> [http://datastax.com/all/image s/cs_logo_color_sm.png >>>> <http://datastax.com/all/images/cs_logo_color_sm.png>] >>>> >>>> >>>> >>>> -- >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> -- >>>> >>>> -Richard L. Burton III >>>> >>>> @rburton >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>> >>> >> >
