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From ESGLinux <esggru...@gmail.com>
Subject Re: Question about HA and Federation
Date Fri, 21 Dec 2012 07:45:12 GMT
Hi,

Finally I´m going to try this:

1 Machine: Active Name Node for NS1
1 Machine: Passive Name Node for NS1
1 Machine: NameNode for NS2 + NameNode for NS3
1 Machine: Secondary NameNode for NS2 + Secondary NameNode for NS3

Is this correct?

thanks,

ESGLinux

2012/12/20 Harsh J <harsh@cloudera.com>

> Btw, you can co-locate NameNodes (unique namespace ones) onto the same
> machine if you need to - the configs easily allow this via rpc/http
> port specifiers.
>
> On Thu, Dec 20, 2012 at 11:33 PM, ESGLinux <esggrupos@gmail.com> wrote:
> > Thank you very much,
> >
> > your answer have clarified me these concepts very much,
> >
> > I didn't understand how could I mix HA and Federation and how many nodes
> I
> > need....
> >
> > Kind Regards,
> >
> > ESGLinux,
> >
> > 2012/12/20 Harsh J <harsh@cloudera.com>
> >>
> >> Yes I think its safe to say that - sorry that I missed out SNNs in my
> >> first response (I counted only the regular serving namenodes) :)
> >>
> >> On Thu, Dec 20, 2012 at 11:25 PM, ESGLinux <esggrupos@gmail.com> wrote:
> >> > Hi again,
> >> >
> >> > So finally the number of nodes are these:
> >> >
> >> > 1 Active NameNode + 1 Passive NameNode (it does the work of the old
> >> > Secondary NameNode) for NS1 NameSpace (these are 2 diferent machines)
> >> > 1 NameNode for NS2 + 1 Secondary NameNode
> >> > 1 NameNode for NS3 + 1 Secondary NameNode
> >> >
> >> > We can say that we need 2 nodes per NameSpace, is that true?
> >> >
> >> > Thanks,
> >> >
> >> > ESGLinux
> >> >
> >> >
> >> >
> >> > 2012/12/20 Harsh J <harsh@cloudera.com>
> >> >>
> >> >> Hi,
> >> >>
> >> >> To put it simply: If you use a NameNode, you need a
> SecondaryNameNode.
> >> >> In HA-mode, a StandbyNameNode acts as a SecondaryNameNode (so you
> >> >> don't need to run an extra).
> >> >>
> >> >> Either way, you definitely need the checkpoint operation happening
> and
> >> >> being monitored for.
> >> >>
> >> >> On Thu, Dec 20, 2012 at 11:09 PM, ESGLinux <esggrupos@gmail.com>
> wrote:
> >> >> > Hi Harsh,
> >> >> >
> >> >> > First thank you very much for your answer,
> >> >> >
> >> >> > following your example:
> >> >> >
> >> >> > You have:
> >> >> >
> >> >> > 1 Active NameNode + 1 Passive NameNode (it does the work of the
old
> >> >> > Secondary NameNode) for NS1 NameSpace (these are 2 diferent
> machines)
> >> >> > 1 NameNode for NS2
> >> >> > 1 NameNode for NS3
> >> >> >
> >> >> > but what about the Secondary Name Nodes for NS2 and NS3? or I
don´t
> >> >> > need
> >> >> > it?
> >> >> > perhaps I´m mixing concepts....
> >> >> >
> >> >> > Thanks again,
> >> >> >
> >> >> > Greetings,
> >> >> >
> >> >> > ESGLinux
> >> >> >
> >> >> >
> >> >> >
> >> >> >
> >> >> > 2012/12/20 Harsh J <harsh@cloudera.com>
> >> >> >>
> >> >> >> Hi ESGLinux,
> >> >> >>
> >> >> >> Federation and HA are two distinct features that share some
common
> >> >> >> properties but nothing more. You can turn on HA for any selected
> >> >> >> Namespace but it is not necessarily needed to be that all
> Namespaces
> >> >> >> have HA.
> >> >> >>
> >> >> >> Perhaps an example will clear it up for you.
> >> >> >>
> >> >> >> I have a local instance that is configured to run several
> >> >> >> namespaces:
> >> >> >> ns1, ns2, and ns3 (Federated Namespaces).
> >> >> >> The namespace ns1 hosts my HBase tables and is critical to
me, so
> I
> >> >> >> have also turned on HA for this namespace alone.
> >> >> >> The other two namespaces ns2 and ns3 are used only for regular
> query
> >> >> >> jobs so its not yet very important for me to have HA on it.
So I
> run
> >> >> >> them without HA.
> >> >> >>
> >> >> >> Thus I have 4 NameNode processes in my cluster in all, given
my
> >> >> >> design
> >> >> >> above: (2 NNs under ns1, in HA mode) + (1 NN of ns2) + (1
NN of
> >> >> >> ns3).
> >> >> >>
> >> >> >> On Thu, Dec 20, 2012 at 10:00 PM, ESGLinux <esggrupos@gmail.com>
> >> >> >> wrote:
> >> >> >> > Hi All,
> >> >> >> >
> >> >> >> > I´m going to test a hadoop cluster and I have a doubt
about HA
> and
> >> >> >> > Federation.
> >> >> >> >
> >> >> >> > With federation I Have a NameNode per namespace and with
HA I
> have
> >> >> >> > an
> >> >> >> > Active
> >> >> >> > NameNode and a standby NameNode.
> >> >> >> >
> >> >> >> > so, as I have sevaral namespaces, do I need an Active
NameNode
> and
> >> >> >> > a
> >> >> >> > standby
> >> >> >> > nameNode per namespace?
> >> >> >> >
> >> >> >> > I have read this documentation but It´s not clear for
me :-(
> >> >> >> >
> >> >> >> >
> >> >> >> >
> >> >> >> >
> >> >> >> >
> https://ccp.cloudera.com/display/CDH4DOC/Introduction+to+Hadoop+High+Availability
> >> >> >> >
> >> >> >> >
> >> >> >> >
> >> >> >> >
> http://hadoop.apache.org/docs/r0.23.0/hadoop-yarn/hadoop-yarn-site/Federation.html
> >> >> >> >
> >> >> >> > Thanks in advance
> >> >> >> >
> >> >> >> > ESGLinux
> >> >> >> >
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >> --
> >> >> >> Harsh J
> >> >> >
> >> >> >
> >> >>
> >> >>
> >> >>
> >> >> --
> >> >> Harsh J
> >> >
> >> >
> >>
> >>
> >>
> >> --
> >> Harsh J
> >
> >
>
>
>
> --
> Harsh J
>

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