Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Plain View
HBase, mail # user - Hbase scans taking a lot of time


+
Vibhav Mundra 2013-01-25, 09:10
Copy link to this message
-
Re: Hbase scans taking a lot of time
Luke Lu 2013-01-25, 17:31
You'll have this problem if you have a large number of column families
being scanned/populated at the same time. Make sure the data you
scan/populate frequently are in the same column family (you can have many
columns in a column family). Unlike BigTable/Hypertable which has the
concept of locality/access groups, HBase always stores column families in
separate files, essentially making column family not only a logic grouping
mechanism but also a physical locality group.
On Fri, Jan 25, 2013 at 1:10 AM, Vibhav Mundra <[EMAIL PROTECTED]> wrote:

> I am facing a very strange problem with HBase.
>
> This what I did:
> a) Create a table, using pre partioned splits.
> b) Also the column familes are zipped with lzo compression.
> c) Using the above configuration I am able to populate 2 million row per
> min in the Hbase.
> d) I have created a table with 300 million odd rows, which roughy took me 3
> hours to populate and the data size is of 25GB.
>
> e) But when I query for data the performance I am getting is very bad.
>    Basically this is what I am seeing: High CPU, no disk I/O and network
> I/O is happening at the rate of 6~7MB secs.
>
>
> Because of this, if I scan the entries of the table using Hive it is taking
> ages.
> Basically it is taking around 24 hours to scan the table. Any idea, of how
> to debug.
>
>
> -Vibhav
>
+
Vibhav Mundra 2013-01-25, 17:59
+
Adrien Mogenet 2013-01-25, 18:04
+
Jean-Marc Spaggiari 2013-01-25, 18:06
+
Vibhav Mundra 2013-01-25, 18:14
+
Jean-Marc Spaggiari 2013-01-25, 18:23
+
lars hofhansl 2013-01-25, 22:00
+
lars hofhansl 2013-01-25, 23:56
+
Alok Kumar 2013-01-26, 06:07
+
Shashwat Shriparv 2013-01-25, 19:13
+
Vibhav Mundra 2013-01-25, 19:25
+
Shashwat Shriparv 2013-01-25, 19:31
+
Vibhav Mundra 2013-01-25, 19:37