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HBase, mail # user - What could cause HBase's writes slower than reads?


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Re: What could cause HBase's writes slower than reads?
yun peng 2012-11-03, 14:09
Hi, the throughput for write-only workload is 450 ops/sec and for read-only
900 ops/sec. I am using the same machine (1-core CPU, 2G mem) for client to
drive workload into hbase/hdfs... one thread is used in client side. For
this workload, it looks client should not be the bottleneck... Btw, is
there anyway to verify this.
Thanks,
Yun

On Sat, Nov 3, 2012 at 1:04 AM, Mohit Anchlia <[EMAIL PROTECTED]>wrote:

> What load do you see on the system? I am wondering if bottleneck is on the
> client side.
>
> On Fri, Nov 2, 2012 at 9:07 PM, yun peng <[EMAIL PROTECTED]> wrote:
>
> > Hi, All,
> > In my HBase cluster, I observed Put() executes faster than a Get(). Since
> > HBase is optimized towards write, I wonder what may affect Put
> performance
> > in a distributed setting below.
> >
> > Hbase setup:
> > My HBase cluster are of three nodes, in which one hosts zookeeper and
> > HMaster, and two slaves. HBase cluster is attached to HDFS which resides
> on
> > a separated cluster. The machines are fairly commodity or lower end, with
> > 2G memory and 1-core CPU.
> >
> > Observed results:
> > I test the Put and Get latency on this setup, and find out Put runs
> slower
> > than Get (which is a bit surprising to me.) In case anyone is interested,
> > in my result, Put() takes around 3000us and Get only in 1000us (so I
> think
> > it does not touch disk).
> >
> > What could possibly slow dow Put() and speed up Get() performance in
> HBase?
> > Does this possibly have to do with distributed setting, like Put needs
> > update multiple (duplicated) copies while Gets only one..  I am quite
> > newbie to HBase internal and not familiar with HBase Put/Get code path,
> has
> > anyone here have similar experiences?
> >
> > Thanks,
> > Yun
> >
>