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From Jim Kellerman <...@powerset.com>
Subject RE: how to find out name node is running
Date Wed, 02 Apr 2008 16:13:13 GMT


---
Jim Kellerman, Senior Engineer; Powerset


> -----Original Message-----
> From: Ipraveen [mailto:praveen.jain@tarmin.com]
> Sent: Wednesday, April 02, 2008 2:57 AM
> To: core-dev@hadoop.apache.org
> Subject: RE: how to find out name node is running
>
>
> hi
>  i dont understand what u are saying,
> and still i am unable to find the namenode status, how would
> i find where it is running?

It is in the configuration.

> and how to i get configuration
> object that can have namenode refrences.?

Configuration conf = new Configuration();

>
>
>
>
> Jim Kellerman wrote:
> >
> > What we do in HBase is the following:
> >
> > this.fs = FileSystem.get(conf);
> > if (this.fs instanceof DistributedFileSystem) {
> >   // Make sure dfs is not in safe mode
> >   String message = "Waiting for dfs to exit safe mode...";
> >   while (((DistributedFileSystem) fs).setSafeMode(
> >     FSConstants.SafeModeAction.SAFEMODE_GET)) {
> >     LOG.info(message);
> >     try {
> >       Thread.sleep(this.threadWakeFrequency);
> >     } catch (InterruptedException e) {
> >       //continue
> >     }
> >   }
> > }
> >
> > In Hadoop 0.16, this will fail if you are running with privileges
> > enabled and your application is not running as Superuser. However,
> > querying the namenode state does not require privileges in
> Hadoop 0.17
> >
> >
> > ---
> > Jim Kellerman, Senior Engineer; Powerset
> >
> >
> >> -----Original Message-----
> >> From: Andy Li [mailto:annndy.lee@gmail.com]
> >> Sent: Tuesday, March 25, 2008 11:54 PM
> >> To: core-dev@hadoop.apache.org
> >> Subject: Re: how to find out name node is running
> >>
> >> I believe this class is the one you are looking for.
> >>
> >> org.apache.hadoop.dfs.namenode.metrics.NameNodeStatistics
> >>
> >> I just went through the API list from the website 0.16.0 and found
> >> this one.
> >> A blunt guess is that if you can invoke these method and get a
> >> response, then you can probably assume the namenode is alive.  But
> >> you will need to do some code hacking to figure out how to
> use it and
> >> study it a little bit to understand what is going on underneath to
> >> confirm.  Just a reference.
> >>
> >> -Andy
> >>
> >> On Tue, Mar 25, 2008 at 11:16 PM, Ipraveen
> <praveen.jain@tarmin.com>
> >> wrote:
> >>
> >> >
> >> > yes you are right Andy , i want to know is there is any
> >> hadoop library
> >> > api which can trace name node or datnode  ?
> >> >
> >> >
> >> > Andy Li-3 wrote:
> >> > >
> >> > > That's relying on Java Virtual Machine process status
> >> tool, similar
> >> > > to
> >> > 'ps
> >> > > aux|grep java' on a Linux?
> >> > >
> >> > > I think the question is whether there is any API from
> >> Hadoop library
> >> > which
> >> > > can monitor the namenode
> >> > > through a Java API without relying 3rd party utility
> >> tool.  Am I right?
> >> > >
> >> > > -Andy
> >> > >
> >> > > On Tue, Mar 25, 2008 at 6:26 AM, Zhu Huijun
> >> > > <nautilushj@gmail.com>
> >> > wrote:
> >> > >
> >> > >> Type the command "jps" in your command window. If your
> >> name node is
> >> > >> running, there will be an output item of "Namenode". Or
> >> check the
> >> > >> web page at http://localhost:50070 if you did not change the
> >> > >> default server host
> >> > and
> >> > >> port of the web.
> >> > >>
> >> > >> 2008/3/25, Ipraveen <praveen.jain@tarmin.com>:
> >> > >> >
> >> > >> >
> >> > >> > hi
> >> > >> > how would i know whether a name node is runnning or not?
> >> > >> > by using hadoop API for java.
> >> > >> >
> >> > >> > regards
> >> > >> > praveen jain
> >> > >> > --
> >> > >> > View this message in context:
> >> > >> >
> >> > >>
> >> >
> >>
> http://www.nabble.com/how-to-find-out-name-node-is-running-tp16274770
> >> p
> >> > 16274770.html
> >> > >> > Sent from the Hadoop core-dev mailing list archive at
> >> Nabble.com.
> >> > >> >
> >> > >> >
> >> > >>
> >> > >
> >> > >
> >> >
> >> > --
> >> > View this message in context:
> >> >
> >>
> http://www.nabble.com/how-to-find-out-name-node-is-running-tp16274770
> >> p
> >> > 16296276.html Sent from the Hadoop core-dev mailing list
> archive at
> >> > Nabble.com.
> >> >
> >> >
> >>
> >> No virus found in this incoming message.
> >> Checked by AVG.
> >> Version: 7.5.519 / Virus Database: 269.22.0/1344 - Release
> >> Date: 3/26/2008 8:52 AM
> >>
> >>
> >
> > No virus found in this outgoing message.
> > Checked by AVG.
> > Version: 7.5.519 / Virus Database: 269.22.0/1344 - Release Date:
> > 3/26/2008
> > 8:52 AM
> >
> >
> >
>
> --
> View this message in context:
> http://www.nabble.com/how-to-find-out-name-node-is-running-tp1
> 6274770p16446350.html
> Sent from the Hadoop core-dev mailing list archive at Nabble.com.
>
>
> No virus found in this incoming message.
> Checked by AVG.
> Version: 7.5.519 / Virus Database: 269.22.4/1355 - Release
> Date: 4/1/2008 5:37 PM
>
>

No virus found in this outgoing message.
Checked by AVG.
Version: 7.5.519 / Virus Database: 269.22.4/1355 - Release Date: 4/1/2008 5:37 PM


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