accumulo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jeremy Kepner <kep...@ll.mit.edu>
Subject Re: HBase and Accumulo
Date Wed, 19 Aug 2015 21:32:12 GMT
Turning off the walog was mostly to shorten the benchmarking cycle
(it allowed us to go from zero to peak ingest in a few seconds).  BAH got
pretty much the same performance results in their paper,
it just took longer for their experiments to run.
So, in this case, we had two different teams doing things different
ways and getting the same result, which is what we like to see.

On Wed, Aug 19, 2015 at 03:27:07PM -0400, Josh Elser wrote:
> Alright, I have to ask... are you referring to the paper that cites
> Accumulo performance without write-ahead logs enabled? I have some
> serious reservations about the relevance of that paper to this
> conversation and just want to make sure people aren't led astray by
> what the actual takeaway should be.
> 
> Jeremy Kepner wrote:
> >A big difference between Accumulo and HBase is the published performance numbers.
> >The Accumulo community has done a good job of continuing to publish up-to-date performance
> >numbers in peer-reviewed venues which allow Accumulo to claim best in the world performance.
> >
> >The HBase community hasn't been doing that so much.  It would be great if they did
because
> >the HBase points on the graphs are old and it would be good to get new ones.
> >
> >
> >On Wed, Aug 19, 2015 at 02:30:58PM -0400, Josh Elser wrote:
> >>Like I've said many times now, it's relative to your actual problem.
> >>If you don't have that much data (or intend to grow into that much
> >>data), it's not an issue. Obviously, this is the case for you.
> >>
> >>However, it is an architectural difference between the two projects
> >>with known limitations for a single metadata region. It's a
> >>difference as what was asked for by Jerry.
> >>
> >>Ted Malaska wrote:
> >>>I've been doing HBase for a long time and never had an issue with region
> >>>count limits and I have clusters with 10s of billions of records.  Many
> >>>there would be issues around a couple Trillion records, but never got that
> >>>high yet.
> >>>
> >>>Ted Malaska
> >>>
> >>>On Wed, Aug 19, 2015 at 2:24 PM, Josh Elser<josh.elser@gmail.com> 
 wrote:
> >>>
> >>>>Oh, one other thing that I should mention (was prompted off-list).
> >>>>
> >>>>(definition time since cross-list now: HBase regions == Accumulo tablets)
> >>>>
> >>>>Accumulo will handle many more regions than HBase does now due to a
> >>>>splittable metadata table. While I was told this was a very long and
> >>>>arduous journey to implement correctly (WRT splitting, merges and bulk
> >>>>loading), users with "too many regions" problems are extremely few and
far
> >>>>between for Accumulo.
> >>>>
> >>>>I was very happy to see effort/design being put into this in HBase. And,
> >>>>just to be fair in criticism/praises, HBase does appear to me to do
> >>>>assignments of regions much faster than Accumulo does on a small cluster
> >>>>(~5-10 nodes). Accumulo may take a few seconds to notice and reassign
> >>>>tablets. I have yet to notice this with HBase (which also could be due
to
> >>>>lack of personal testing).
> >>>>
> >>>>
> >>>>Jerry He wrote:
> >>>>
> >>>>>Hi, folks
> >>>>>
> >>>>>We have people that are evaluating HBase vs Accumulo.
> >>>>>Security is an important factor.
> >>>>>
> >>>>>But I think after the Cell security was added in HBase, there is
no more
> >>>>>real gap compared to Accumulo.
> >>>>>
> >>>>>I know we have both HBase and Accumulo experts on this list.
> >>>>>Could someone shred more light?
> >>>>>I am looking for real gap comparing HBase to Accumulo if there is
any so
> >>>>>that I can be prepared to address them. This is not limited to the
> >>>>>security
> >>>>>area.
> >>>>>
> >>>>>There are differences in some features and implementations. But they
don't
> >>>>>see like real 'gaps'.
> >>>>>
> >>>>>Any comments and feedbacks are welcome.
> >>>>>
> >>>>>Thanks,
> >>>>>
> >>>>>Jerry
> >>>>>
> >>>>>

Mime
View raw message