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From Alberich de megres <alberich...@gmail.com>
Subject Re: HDFS Blockreport question
Date Tue, 06 Apr 2010 13:47:20 GMT
Thanks!

I'm already using eclipse to browse the code.
In this scenario, i could understand that java serializes the object
through the network and its parameters.  is that ok?

For example, if i want to make a pure C library (with no JNI
interfaces).. is it possible/feasible? or it will be like to freeze
the hell?

Thanks once again!!!


On Sat, Apr 3, 2010 at 1:54 AM, Ryan Rawson <ryanobjc@gmail.com> wrote:
> If you look at the getProxy code it passes an "Invoker" (or something
> like that) which the proxy code uses to delegate calls TO.  The
> Invoker will call another class "Client" which has sub-classes like
> Call, and Connection which wrap the actual java IO.  This all lives in
> the org.apache.hadoop.ipc package.
>
> Be sure to use a good IDE like IJ or Eclipse to browse the code, it
> makes following all this stuff much easier.
>
>
>
>
>
> On Fri, Apr 2, 2010 at 4:39 PM, Alberich de megres
> <alberich2k5@gmail.com> wrote:
>> Hi again!
>>
>> Anyone could help me?
>> I could not understand how RPC class works. For me, only tries to
>> instantiates a single interfaces with no declaration for some methods
>> like blockreport. But then it uses rpc.getproxy to get new class wich
>> send messages with name node.
>>
>> I'm sorry for this silly question, but i am really lost at this point.
>>
>> Thanks for the patience.
>>
>>
>>
>> On Fri, Apr 2, 2010 at 2:11 AM, Alberich de megres
>> <alberich2k5@gmail.com> wrote:
>>> Hi Jay!
>>>
>>> thanks for the answear but i'm asking for what it works it sends?
>>> blockreport is an interface in DatanodeProtocol that has no
>>> declaration.
>>>
>>> thanks!
>>>
>>>
>>>
>>> On Thu, Apr 1, 2010 at 5:50 PM, Jay Booth <jaybooth@gmail.com> wrote:
>>>> In DataNode:
>>>> public DatanodeProtocol namenode
>>>>
>>>> It's not a reference to an actual namenode, it's a wrapper for a network
>>>> protocol created by that RPC.waitForProxy call -- so when it calls
>>>> namenode.blockReport, it's sending that information over RPC to the namenode
>>>> instance over the network
>>>>
>>>> On Thu, Apr 1, 2010 at 5:50 AM, Alberich de megres <alberich2k5@gmail.com>wrote:
>>>>
>>>>> Hi everyone!
>>>>>
>>>>> sailing throught the hdfs source code that comes with hadoop 0.20.2,
i
>>>>> could not understand how hdfs sends blockreport to nameNode.
>>>>>
>>>>> As i can see, in
>>>>> src/hdfs/org/apache/hadoop/hdfs/server/datanode/DataNode.java we
>>>>> create this.namenode interface with RPC.waitForProxy call (wich i
>>>>> could not understand which class it instantiates, and how it works).
>>>>>
>>>>> After that, datanode generates block list report (blockListAsLongs)
>>>>> with data.getBlockReport, and call this.namenode.blockReport(..),
>>>>> inside namenode.blockReport it calls again namesystem.processReport.
>>>>> This leads to an update of block lists inside nameserver.
>>>>>
>>>>> But how it sends over the network this blockreport?
>>>>>
>>>>> Anyone can point me some light?
>>>>>
>>>>> thanks for all!
>>>>> (and sorry for the newbie question)
>>>>>
>>>>> Alberich
>>>>>
>>>>
>>>
>>
>

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