hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ted Dunning <tdunn...@maprtech.com>
Subject Re: 0.90 latency performance, cdh3b4
Date Wed, 20 Apr 2011 20:14:29 GMT
FS latency shouldn't matter with your 99.9% cache hit rate as reported.

On Wed, Apr 20, 2011 at 12:55 PM, Dmitriy Lyubimov <dlieu.7@gmail.com>wrote:

> Yes -- I already looked thru 'regionserver' metrics some time ago in
> hbase book. And i am not sure there's a 'inner ttlb' metric.
>
> There are fs latency metrics there but nothing for the respons times.
> fs latency is essentially hdfs latency AFAICT and that would not be
> relevant to what i am asking for (for as long as we are hitting LRU
> block cache anyway). we are not hitting fs.
>
> Unless there are more metrics than listed in the Hbase Book?
>
>
> On Wed, Apr 20, 2011 at 12:46 PM, Stack <stack@duboce.net> wrote:
> > Enable rpc logging.  Will show in your ganglia.  See metrics article
> > on hbase home page.
> >
> > On Wed, Apr 20, 2011 at 12:44 PM, Dmitriy Lyubimov <dlieu.7@gmail.com>
> wrote:
> >> Is there any way to log 'inner' TTLB times the region server incurs for
> reads?
> >>
> >>
> >> On Wed, Apr 20, 2011 at 12:43 PM, Dmitriy Lyubimov <dlieu.7@gmail.com>
> wrote:
> >>> i just enabled debug logging for o.a.h.hbase logger in that particular
> >>> region server... so far not much except for LRUBlock cache spitting
> >>> metrics ..
> >>>
> >>> 2011-04-20 12:28:48,375 DEBUG
> >>> org.apache.hadoop.hbase.io.hfile.LruBlockCache: LRU Stats: total=8.26
> >>> MB, free=190.08 MB, max=198.34 MB, blocks=112, accesses=55732209,
> >>> hits=55732083, hitRatio=99.99%%, cachingAccesses=55732195,
> >>> cachingHits=55732083, cachingHitsRatio=99.99%%, evictions=0,
> >>> evicted=0, evictedPerRun=NaN
> >>> 2011-04-20 12:33:48,375 DEBUG
> >>> org.apache.hadoop.hbase.io.hfile.LruBlockCache: LRU Stats: total=8.26
> >>> MB, free=190.08 MB, max=198.34 MB, blocks=112, accesses=56703200,
> >>> hits=56703074, hitRatio=99.99%%, cachingAccesses=56703186,
> >>> cachingHits=56703074, cachingHitsRatio=99.99%%, evictions=0,
> >>> evicted=0, evictedPerRun=NaN
> >>> 2011-04-20 12:38:48,375 DEBUG
> >>> org.apache.hadoop.hbase.io.hfile.LruBlockCache: LRU Stats: total=8.26
> >>> MB, free=190.08 MB, max=198.34 MB, blocks=112, accesses=57708231,
> >>> hits=57708105, hitRatio=99.99%%, cachingAccesses=57708217,
> >>> cachingHits=57708105, cachingHitsRatio=99.99%%, evictions=0,
> >>> evicted=0, evictedPerRun=NaN
> >>>
> >>>
> >>> On Wed, Apr 20, 2011 at 12:35 PM, Stack <stack@duboce.net> wrote:
> >>>> If one region only, then its located on a single regionserver.  Tail
> >>>> that regionservers logs.  It might tell us something.
> >>>> St.Ack
> >>>>
> >>>> On Wed, Apr 20, 2011 at 12:25 PM, Stack <stack@duboce.net> wrote:
> >>>>> On Wed, Apr 20, 2011 at 12:25 PM, Stack <stack@duboce.net>
wrote:
> >>>>>> On Tue, Apr 19, 2011 at 4:46 PM, Dmitriy Lyubimov <
> dlyubimov@apache.org> wrote:
> >>>>>>> Right now i am shooting scans returning between 3 and 40
rows and
> >>>>>>> regardless of data size, approximately 500-400 QPS. The
data tables
> >>>>>>> are almost empty and in-memory, so they surely should fit
in those
> 40%
> >>>>>>> heap dedicated to them.
> >>>>>>>
> >>>>>>
> >>>>>> How many clients are going against the cluster?  If you use
less, do
> >>>>>> your numbers improve?
> >>>>>>
> >>>>>
> >>>>> And all these clients are going against a single 40 row table?
> >>>>> St.Ack
> >>>>>
> >>>>
> >>>
> >>
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message