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Hive >> mail # user >> sqoop import into hive shows more rows RE: sqoop, hive and lzo and cdh3u3 - not creating in index automatically


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sqoop import into hive shows more rows RE: sqoop, hive and lzo and cdh3u3 - not creating in index automatically
Hi,

When sqoop importing into hive with snappy compression and as sequence file, the number of rows imported is shown correctly in the logging(12/06/21 09:34:24 INFO mapreduce.ImportJobBase: Retrieved 10000 records.) but when I do count(*) on the hive table I get 13714 rows.  Also the data when I do select * from table limit 100; gives garbage.

What am I not setting right?
Thanks,
Chalcy

-----Original Message-----
From: Chalcy Raja [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 19, 2012 8:23 AM
To: [EMAIL PROTECTED]; '[EMAIL PROTECTED]'
Subject: RE: sqoop, hive and lzo and cdh3u3 - not creating in index automatically

Describe formatted tablename is a great DDL.  

For one table sqoop imported into hive table as sequence file, I see the metadata starts with "SEQ-!".  

I created another table like the one which shows SEQ in the metafile and loaded data into this table and I do not see SEQ in the meta data.  I'll try head command and see what is going on.

Thanks,
Chalcy

-----Original Message-----
From: Bejoy KS [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 19, 2012 2:59 AM
To: [EMAIL PROTECTED]
Subject: Re: sqoop, hive and lzo and cdh3u3 - not creating in index automatically

Hi Chalcy

When you create a table you do specify the format of how the data is stored in hdfs. This value can be determined using , describe extended or describe formatted at any later point.

Try out
Describe formatted <tableName>;

To ensure the file in hdfs is in SequenceFileFormat, you can check the metadata. Meta data contains information like the compression codec used etc, from the first few characters of a Sequence file . Try linux head command on the sequence file to get those details.
Regards
Bejoy KS

Sent from handheld, please excuse typos.

-----Original Message-----
From: Chalcy Raja <[EMAIL PROTECTED]>
Date: Tue, 19 Jun 2012 01:32:52
To: [EMAIL PROTECTED]<[EMAIL PROTECTED]>; '[EMAIL PROTECTED]'<[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
Subject: RE: sqoop, hive and lzo and cdh3u3 - not creating in index  automatically

I did figure out how to compress data from an uncomressed data in hive table.  I also created a table as sequence file format.  

Is there a way to know if a hive table (hdfs file underneath) is in sequence file format?  Describe extended table does not give the file format.

Thanks,
Chalcy

-----Original Message-----
From: Chalcy Raja [mailto:[EMAIL PROTECTED]]
Sent: Monday, June 18, 2012 3:28 PM
To: [EMAIL PROTECTED]; '[EMAIL PROTECTED]'
Subject: RE: sqoop, hive and lzo and cdh3u3 - not creating in index automatically

Snappy with sequence file works well for us.  We'll have to decide which one suits our needs.  

Is there a way to convert exiting hdfs in text format to convert to sequence files?

Thanks for all your input,
Chalcy  

-----Original Message-----
From: Chalcy Raja [mailto:[EMAIL PROTECTED]]
Sent: Monday, June 18, 2012 1:47 PM
To: [EMAIL PROTECTED]; '[EMAIL PROTECTED]'
Subject: RE: sqoop, hive and lzo and cdh3u3 - not creating in index automatically

It is there.  I have io.compression.codecs in core-site.xml.  There is not error or warn in the sqoop to hive import which indicates anything.  

The only reason we want to go to lzo is because snappy is not splittable.  

Thanks,
Chalcy

-----Original Message-----
From: Bejoy KS [mailto:[EMAIL PROTECTED]]
Sent: Monday, June 18, 2012 10:39 AM
To: [EMAIL PROTECTED]
Subject: Re: sqoop, hive and lzo and cdh3u3 - not creating in index automatically

Hi Chalcy

Lzo indexing not working, Is Lzo codec class available in 'io.compression.codec' property in core-site.xml?

Snappy is not splittable on its own. But sequence files are splittable so when used together snappy gains the advantage of splittability.

Regards
Bejoy KS

Sent from handheld, please excuse typos.

-----Original Message-----
From: Chalcy Raja <[EMAIL PROTECTED]>
Date: Mon, 18 Jun 2012 14:31:36
To: [EMAIL PROTECTED]<[EMAIL PROTECTED]>; '[EMAIL PROTECTED]'<[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
Subject: RE: sqoop, hive and lzo and cdh3u3 - not creating in index  automatically

Hi Bejoy,

The weird thing is I did not get any errors.  The sqoop import will not go to the second phase where it creates lzo index.

We did deploy the native libraries, except hadoop-lzo lib which we copied after we built in another machine.  We did the same thing on the test machine also.  

I'll try snappy with sequence file also.  Will snappy with sequence file is naturally splittable on the block (one mapper per block)?

Yes, it is cumbersome to create lzo library, then create the file and then create index.

Thanks,
Chalcy

From: Bejoy KS [mailto:[EMAIL PROTECTED]]
Sent: Monday, June 18, 2012 10:04 AM
To: [EMAIL PROTECTED]
Subject: Re: sqoop, hive and lzo and cdh3u3 - not creating in index automatically

Hi Chalcy

Did you notice any warnings related to lzo codec on your mapreduce task logs or on sqoop logs?

It could be because LZO libs are not available on the TaskTracker nodes. These are native libs and are tied to OS, so if you have done an OS upgrade then you need to rebuild and deploy these native libs as well (a simple copy of native libs based older OS may not work as desired).

Like Edward suggested, snappy + sequence is a great combination.

Regards
Bejoy KS

Sent from handheld, please excuse typos.

From: Edward Capriolo <[EMAIL PROTECTED]>
Date: Mon, 18 Jun 2012 09:32:01
To: <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
Subject: Re: sqoop, hive and lzo and cdh3u3 - not creating in index automatically

Have you considered switching to sequence files using snappy compression (or lzo). IIRC the process of generating LZO files and then generating an index on top of these is cumbersome. When sequence files are directly splittable.

On Mon, Jun 18, 2012 at 9:16 AM, Chalcy Raja <[EMAIL PROTECTED]> wrote:
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB