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From Gary Helmling <ghelml...@gmail.com>
Subject Re: Themis : implements cross-row/corss-table transaction on HBase.
Date Tue, 08 Jul 2014 17:04:54 GMT
Hi Jianwei,

You may also want to take a look at the generic client transaction API
being proposed in HBASE-11447:
https://issues.apache.org/jira/browse/HBASE-11447

I think it would be useful to have the Themis perspective there, and
whether the proposed API meets your needs and requirements.



On Tue, Jul 8, 2014 at 9:10 AM, Ted Yu <yuzhihong@gmail.com> wrote:

> Jianwei:
> You may want to update the comment for ThemisScan :
>
> //a wrapper class of Put in HBase which not expose timestamp to user
> public class ThemisScan extends ThemisRead {
>
> Is there plan to support append / increment as part of the transaction ?
>
> Currently Themis depends on 0.94.11
> Is there plan to support 0.96+ releases ?
>
> Thanks
>
>
> On Tue, Jul 8, 2014 at 12:34 AM, 崔建伟 <cuijianwei@xiaomi.com> wrote:
>
> > Hi everyone, I want to introduce our open-source project Themis which
> > implements cross-row/corss-table transaction on HBase.
> >
> > Themis follows google's percolator algorithm(
> > http://research.google.com/pubs/pub36726.html), which provides
> > ACID-compliant transaction and snapshot isolation. The cross-row
> > transaction is based on HBase's single-row atomic semantics and doesn't
> use
> > a central transaction server, so that supports linear-scalability.
> >
> > Themis depends on a timestamp server to provides global strictly
> > incremental timestamp to define the order of transactions, which will be
> > used to resolve the write-write and read-write conflicts. The timestamp
> > server is lightweight and could achieve hight throughput(500, 000 + qps),
> > and Themis will batch timestamp requests across transactions in one Rpc,
> so
> > that it won't become the bottleneck of the system even when processing
> > billions of transactions every day.
> >
> > Although Themis could be implemented totally in client-side, we adopt
> > coprocessor framework of HBase to achieve higher performance. Themis
> > includes a client-side library to provides transaction APIs, such as
> > themisPut/themisGet/themisScan/themisDelete, and a coprocessor library
> > loaded on regionserver. Therefore, Themis could be used without changing
> > the code and logic of HBase.
> >
> > We have been validating the correctness of Themis for a few months by a
> > AccountTransfer simulation program, which concurrently does cross-row
> > transactions by transferring money among different accounts(each account
> is
> > a row in HBase) and verifies total money of all accounts doesn't change
> in
> > the simulation. We have also run Themis on our production environment.
> >
> > We test the performance of Themis and get comparable result as
> percolator.
> > The single-column transaction represents the worst performance case for
> > Themis compared with HBase, the result is:
> > 1) For read, the performance of percolator is 90% of HBase;
> > 2) For write, the performance of percolator is 23% of HBase.
> > The write performance drops a lot because Themis uses two-phase commit
> > protocol to achieve ACID of transaction. For multi-row write, we improve
> > the performance by paralleling all writes of pre-write phase. For
> > single-row write, we are optimizing two-phase commit protocol to achieve
> > better performance and will update the result when it is ready. The
> details
> > of performance result could be found in github.
> >
> > The repository and introduction of Themis include:
> > 1. Themis github: https://github.com/XiaoMi/themis/. The source code,
> > performance test result and user guide could be found here.
> > 2. Themis jira : https://issues.apache.org/jira/browse/HBASE-10999
> > 3. Chronos github: https://github.com/XiaoMi/chronos. Chronos is our
> > open-source high-availability, high-performance timestamp server to
> provide
> > global strictly incremental timestamp for Themis.
> >
> > If you find Themis interesting, please leave us comment in the mail, jira
> > or github.
> >
> > Best
> > cuijianwei
> >
>

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