I have left some comments behind on the jira.
We could argue over what's the right thing to do (and we will on the
Jira) - but the higher level problem is that this is another case
where
backwards compatibility with existing semantics of this option was
not
carried over. Neither was there any notification to admins about this
change. The change notes just do not convey the import of this
change to
existing deployments (incidentally 1463 was classified as 'Bug Fix' -
not that putting under 'Incompatible Fix' would have helped imho).
Would request the board/committers to consider setting up something
along the lines of:
1. have something better than Change Notes to convey interface
changes
2. a field in the JIRA that marks it out as important from interface
change point of view (with notes on what's changing). This could
be used
to auto-populate #1
3. Some way of auto-subscribing to bugs that are causing interface
changes (even an email filter on the jira mails would do).
As Hadoop user base keeps growing - and gets used for 'production'
tasks
- I think it's absolutely essential that users/admins can keep in
tune
with changes that affect their deployments. Otherwise - any
organization
other than Yahoo would have tough time upgrading.
(I am new to open-source - but surely this has been solved before?)
Joydeep
-----Original Message-----
From: Hairong Kuang [mailto:[EMAIL PROTECTED]
Sent: Monday, March 10, 2008 5:17 PM
To: [email protected]
Subject: Re: Does Hadoop Honor Reserved Space?
I think you have a misunderstanding of the reserved parameter. As I
commented on hadoop-1463, remember that dfs.du.reserve is the
space for
non-dfs usage, including the space for map/reduce, other
application, fs
meta-data etc. In your case since /usr already takes 45GB, it far
exceeds
the reserved limit 1G. You should set the reserved space to be 50G.
Hairong
On 3/10/08 4:54 PM, "Joydeep Sen Sarma" <[EMAIL PROTECTED]> wrote:
Filed https://issues.apache.org/jira/browse/HADOOP-2991
-----Original Message-----
From: Joydeep Sen Sarma [mailto:[EMAIL PROTECTED]
Sent: Monday, March 10, 2008 12:56 PM
To: [email protected]; [email protected]
Cc: Pete Wyckoff
Subject: RE: Does Hadoop Honor Reserved Space?
folks - Jimmy is right - as we have unfortunately hit it as well:
https://issues.apache.org/jira/browse/HADOOP-1463 caused a
regression.
we have left some comments on the bug - but can't reopen it.
this is going to be affecting all 0.15 and 0.16 deployments!
-----Original Message-----
From: Hairong Kuang [mailto:[EMAIL PROTECTED]
Sent: Thu 3/6/2008 2:01 PM
To: [email protected]
Subject: Re: Does Hadoop Honor Reserved Space?
In addition to the version, could you please send us a copy of the
datanode
report by running the command bin/hadoop dfsadmin -report?
Thanks,
Hairong
On 3/6/08 11:56 AM, "Joydeep Sen Sarma" <[EMAIL PROTECTED]>
wrote:
but intermediate data is stored in a different directory from
dfs/data
(something like mapred/local by default i think).
what version are u running?
-----Original Message-----
From: Ashwinder Ahluwalia on behalf of [EMAIL PROTECTED]
Sent: Thu 3/6/2008 10:14 AM
To: [email protected]
Subject: RE: Does Hadoop Honor Reserved Space?
I've run into a similar issue in the past. From what I understand,
this
parameter only controls the HDFS space usage. However, the
intermediate data
in
the map reduce job is stored on the local file system (not HDFS)
and
is not
subject to this configuration.
In the past I have used mapred.local.dir.minspacekill and
mapred.local.dir.minspacestart to control the amount of space
that is
allowable
for use by this temporary data.
Not sure if that is the best approach though, so I'd love to hear
what
other
people have done. In your case, you have a map-red job that will
consume too
much space (without setting a limit, you didn't have enough disk
capacity for
the job), so looking at mapred.output.compress and
mapred.compress.map.output
might be useful to decrease the job's disk requirements.
--Ash
-----Original Message-----
From: Jimmy Wan [mailto:[EMAIL PROTECTED]
Sent: Thursday, March 06, 2008 9:56 AM
To: [email protected]
Subject: Does Hadoop Honor Reserved Space?
I've got 2 datanodes setup with the following configuration
parameter:
<property>
<name>dfs.datanode.du.reserved</name>
<value>429496729600</value>
<description>Reserved space in bytes per volume. Always leave this
much
space free for non dfs use.
</description>
</property>
Both are housed on 800GB volumes, so I thought this would keep
about
half
the volume free for non-HDFS usage.
After some long running jobs last night, both disk volumes were
completely
filled. The bulk of the data was in:
${my.hadoop.tmp.dir}/hadoop-hadoop/dfs/data
This is running as the user hadoop.
Am I interpretting these parameters incorrectly?
I noticed this issue, but it is marked as closed:
http://issues.apache.org/jira/browse/HADOOP-2549
