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HBase >> mail # user >> Slow random reads, SocketTimeoutExceptions


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Re: Slow random reads, SocketTimeoutExceptions
A cell-size is about 300 bytes in my case. (row-key's length is 32 bytes)
In my current scenario, I generated 100 tables with a single column family.
I'm inserting between 100k and 300k rows per second, depending on my
settings - but it's not the purpose here, I'm mostly trying to get good
concurrent (random) read/write performances. My benchmark is running on 30
nodes.

On Wed, Jul 11, 2012 at 10:22 PM, Asaf Mesika <[EMAIL PROTECTED]> wrote:

> What's your cell value size?
> What do you mean by 100 tables in one column family?
> Can you please specify what was your insert rate and how many nodes you
> have?
>
> Sent from my iPhone
>
> On 11 ביול 2012, at 22:08, Adrien Mogenet <[EMAIL PROTECTED]>
> wrote:
>
> Hi there,
>
> I'm discovering HBase and comparing it with other distributed database I
> know much better. I am currently stressing my testing platform (servers
> with 32 GB Ram, 16 GB allocated to HBase JVM) and I'm observing strange
> performances... I'm putting tons of well-spred data (100 Tables of 100M
> rows in a single column family) and then I'm performing random reads. I get
> good read performances while the table does not have too much data in it,
> but in a big table, I only get around 100/300 qps. I'm not swapping, don't
> see any long pauses due to GC and insert rate is still very high, but
> nothing come from reads and it often results in a SocketTimeoutException
> (while waiting for channel to be ready for read exceptions, etc.).
>
> I noticed that certain StoreFile were very big (~120 GB) and I adjusted
> compaction strategy to no compact such big files (I don't know if it can be
> related to my issue).
>
> I noticed that when I'm stressing my cluster with Get requests, everything
> *looks* fine until a RegionServer does not yield a data locally and fetch
> it from HDFS, resulting in high and long network use, more than 60 seconds,
> that's throwing SocketTimeoutException).
>
> How does HBase handle data locality for random accesses ? Could it be a
> lead to solve this kind of issue ?
> My block cache of 5 GB is not full at all...
>
> --
> Adrien Mogenet
> http://www.mogenet.me
>

--
Adrien Mogenet
06.59.16.64.22
http://www.mogenet.me