Comments for Sujee Maniyam's Blog

Comment on Performance testing a HBase cluster by Sujee Maniyam

Sujee Maniyam — Mon, 19 Sep 2011 17:57:08 +0000

1) Using hbase shell you can see the data in a table.
on terminal, bring up hbase shell
# hbase shell
> scan ‘table’
this will print out all entries in the table.

If you just want to see a few, then use LIMIT
> scan ‘table’ , {LIMIT => 10}
see first 10 rows

2) To monitor activity, use Hbase UI (http://hmaster:60010)
you will see requests for each region server

Comment on Performance testing a HBase cluster by vamshi

vamshi — Sun, 18 Sep 2011 10:11:15 +0000

Hi, this post is very good.But i have one basic doubt, all the inserted data by clients go to which place in hbase?? How can we see that inserted data in the hbase? One more thing is , during its operation of random read/random write, the namenode,tasktracker, Jobtracker web UI is not showing anything..But i can see the results and working on the console.
Can you help me how to check the above mentioned things?
Thank you

Comment on [tech] Hbase Map Reduce Example by giri

giri — Thu, 28 Jul 2011 18:31:34 +0000

Hi Sujee ,

really very good doc …..

thanks

Comment on Amazon Elastic Map Reduce (EMR): Beyond Basics by James Carter

James Carter — Sat, 16 Jul 2011 19:44:03 +0000

This article is a great one. It describes all clearly. I really liked it. It’s very helpful. I was looking for such articles. I have read a article here “http://www.techyv.com/article/amazon-elastic-mapreduce-cloud-computing” which is almost like this.

Comment on [tech] Hbase Map Reduce Example by Amarjeet

Amarjeet — Tue, 12 Jul 2011 09:14:29 +0000

Hi Sujee,

by memory data I dont mean ‘DATA JOINS’.

I Mean:
lets take this example in your blog -
you are reading input from Hbase table – ‘access_logs’ and then process it and put your output in ‘summary’ table.

What I want is:
I wish I could take input from some Map or list (present in-memory only or create myself in code).

I hope you understand now.

Comment on [tech] Hbase Map Reduce Example by admin

admin — Mon, 11 Jul 2011 17:38:55 +0000

@Amarjeet
not sure what do you mean by using-memory data as Mapreduce input. are you talking about doing ‘data joins’ ?
If that is the case, then you might try this:
- load your data xref data into a memory cache like memcached (this can be done in the driver code of mapreduce)
- in your mapper, access memcached to xref

Comment on [tech] Hbase Map Reduce Example by Amarjeet

Amarjeet — Mon, 11 Jul 2011 11:07:40 +0000

Hi Sujee,

Thanks for great tutorial!!

I am able to run the mapreduce application using HDFS and HBase both.

But now I want to use in memory data to be used as input to MapReduce application.

e.g. – I have few data maps in my memory and want to use those in spite of Hbase table as input.

Could you please guide me for this??

Timely reply will be appreciated very much.

Thanks in advance!!

Comment on Membase Java tutorial [Tech] by admin

admin — Fri, 08 Jul 2011 22:41:26 +0000

@Matthew
look at Membase dashboard, it will show items in memory / disk …etc.

Also you can shutdown membase, bring it back up and try to read the values you set previously.

Comment on Membase Java tutorial [Tech] by Matthew

Matthew — Fri, 08 Jul 2011 05:32:49 +0000

Hi ,

Very neat tutorial! but when I tried running the code, I felt that the data dint get committed to the disk, rather it was the memcached that was getting used though I specified the Membase port in the memcachedClient instance. Please let me know how to confirm whether Membase was actually used (data persistence).

Comment on [tech] Hbase Map Reduce Example by admin

admin — Wed, 15 Jun 2011 22:01:09 +0000

@Anil
the table will split as it exceeds the ‘region max size’ (default 256M, I think).