Is there any error messages on your TaskTracker logs related to compression like 'Codec not found' or so ?
Bejoy K S
From handheld, Please excuse typos.
From: Juwei Shi <[EMAIL PROTECTED]>
Date: Fri, 17 Feb 2012 17:48:08
To: <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
Subject: Re: reduce output compression of Terasort
We use LZO, so the value is
mapred.output.compression.codec = com.hadoop.compression.lzo.LzoCodec
No compressed file in HDFS.
2012/2/17 Bejoy Ks <[EMAIL PROTECTED]>
> Hi Juwei
> What is the value for mapred.output.compression.codec? It'd be
> better to determine whether the output files are compressed by getting the
> codec of the same and not just from the size of files.
> On Fri, Feb 17, 2012 at 12:07 PM, Juwei Shi <[EMAIL PROTECTED]> wrote:
>> I am benchmarking the cluster using the Terasort package of Hadoop
>> 0.20.2. I enabled compression for both map output (*
>> mapred.compress.map.output*) and reduce output (*mapred.output.compress*).
>> I checked the parameter in Job.xml, both are true. I can see that the
>> compression for Map output works, but it seems that the compression for
>> reduce output does not work. The output of the job on HDFS is also 1TB.
>> - Juwei
- Juwei Shi (史巨伟)