hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Dmitriy Lyubimov <dlie...@gmail.com>
Subject Re: 0.90 latency performance, cdh3b4
Date Wed, 20 Apr 2011 20:38:51 GMT
btw, Ted, your version of YCSB in github should show TTLBs, right?

On Wed, Apr 20, 2011 at 1:14 PM, Ted Dunning <tdunning@maprtech.com> wrote:
> 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
View raw message