hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Praveen Sripati <praveensrip...@gmail.com>
Subject Re: Re: how to select the position of a block
Date Wed, 07 Dec 2011 16:58:57 GMT
Not sure why, but I was able to find ReplicationTargetChooser.java only in
branch-1.0 and not in trunk, 21, 22 and 23.

Regards,
Praveen

2011/12/7 郭冲 <guochonghenu@126.com>

>
>
> 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" <harsh@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?
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message