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Hadoop, mail # user - Warnings?


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Re: Warnings?
Kevin Burton 2013-04-29, 18:19
If it doesn't work what are my options? Is there source that I can download and compile?

On Apr 29, 2013, at 10:31 AM, Ted Xu <[EMAIL PROTECTED]> wrote:

> Hi Kevin,
>
> Native libraries are those implemented using C/C++, which only provide code level portability (instead of binary level portability, as Java do). That is to say, the binaries provided by CDH4 distribution will in most cases be broken in your environment.
>
> To check if your native libraries are working or not, you can follow the instructions I sent previously. Quote as following.
>
> <blockquote>
> During runtime, check the hadoop log files for your MapReduce tasks.
>
> If everything is all right, then: DEBUG util.NativeCodeLoader - Trying to load the custom-built native-hadoop library... INFO util.NativeCodeLoader - Loaded the native-hadoop library
> If something goes wrong, then: INFO util.NativeCodeLoader - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
> </blokquote>
>
>
> On Mon, Apr 29, 2013 at 10:21 AM, Kevin Burton <[EMAIL PROTECTED]> wrote:
>> I looked at the link you provided and found the Ubuntu is one of the “supported platforms” but it doesn’t give any information on how to obtain it or build it. Any idea why it is not includde as part of the Cloudera CDH4 distribution? I followed the installation instructions (mostly apt-get install . . . .) but I fail to see the libhadoop.so.  In order to avoid this warning do I need to download the Apache distribution? Which one?
>>
>>  
>>
>> For the warnings about the configuration I looked in my configuration and for this specific example I don’t see ‘session.id’ used anywhere. It must be used by default. If so why is the deprecated default being used?
>>
>>  
>>
>> As for the two warnings about counters. I know I have not implemented any code for counters so again this must be something internal. Is there something I am doing to trigger this?
>>
>>  
>>
>> So I can avoid them what are “hadoop generic options”?
>>
>>  
>>
>> Thanks again.
>>
>>  
>>
>> Kevin
>>
>>  
>>
>> From: Ted Xu [mailto:[EMAIL PROTECTED]]
>> Sent: Friday, April 26, 2013 10:49 PM
>> To: [EMAIL PROTECTED]
>> Subject: Re: Warnings?
>>
>>  
>>
>> Hi Kevin,
>>
>>  
>>
>> Please see my comments inline,
>>
>>  
>>
>> On Sat, Apr 27, 2013 at 11:24 AM, Kevin Burton <[EMAIL PROTECTED]> wrote:
>>
>> Is the native library not available for Ubuntu? If so how do I load it?
>>
>> Native libraries usually requires recompile, for more information please refer Native Libraries.
>>
>>  
>>
>>  
>>
>> Can I tell which key is off? Since I am just starting I would want to be as up to date as possible. It is out of date probably because I copied my examples from books and tutorials.
>>
>>  
>>
>> I think the warning messages are telling it already, "xxx is deprecated, use xxx instead...". In fact, most of the configure keys are changed from hadoop 1.x to 2.x. The compatibility change may later documented on http://wiki.apache.org/hadoop/Compatibility.
>>
>>  
>>
>> The main class does derive from Tool. Should I ignore this warning as it seems to be in error?
>>
>> Of course you can ignore this warning as long as you don't use hadoop generic options.
>>
>>  
>>
>>  
>>
>> Thank you.
>>
>>
>> On Apr 26, 2013, at 7:49 PM, Ted Xu <[EMAIL PROTECTED]> wrote:
>>
>> Hi,
>>
>>  
>>
>> First warning is saying hadoop cannot load native library, usually a compression codec. In that case, hadoop will use java implementation instead, which is slower.
>>
>>  
>>
>> Second is caused by hadoop 1.x/2.x configuration key change. You're using a 1.x style key under 2.x, yet hadoop still guarantees backward compatibility.
>>
>>  
>>
>> Third is saying that the main class of a hadoop application is recommanded to implement org.apache.hadoop.util.Tool, or else generic command line options (e.g., -D options) will not supported.  
>>
>>  
>>
>> On Sat, Apr 27, 2013 at 5:51 AM, <[EMAIL PROTECTED]> wrote: