isGoodTarget() in ReplicationTargetChooser.java judge if a node is a good
node, it will consider the disk space , load , and the rack which it located
has too much nodes or not .Thanks!
At 2011-12-07 13:01:26,"Harsh J" <ha...@cloudera.com> wrote:
>Moving discussion to hdfs-dev.
>
>DataNodes report disk usage (space) and current transfer thread counts (load)
>periodically to the NameNode. NameNode uses this information to make a
>decision while building the pipeline DNs for your client request. I believe
>the class is called something like ReplicationTargetChooser (off the top of my
>mind), and you can take a look at the logic involved there in selecting any
>form of node (isGoodTarget or summat). Then work your way downwards to see how
>the information flows.
>
>On 07-Dec-2011, at 8:36 AM, 郭冲 wrote:
>
>> Hadoop:The Definitive Guide said that when the client is out of the
>> cluster, hadoop will select the storage position of a block randomly,but it
>> will not select the datanode which is too busy or too full.
>>
>> so i want to kown that how hadoop judge or measure a datanode is full or
>> not?
>
