What's the status of IPv6 support?

[Andrew Pennebaker <ap...@42six.com>]

When will Hadoop get better IPv6 support? It would be nice if Ubuntu users
didn't have to disable IPv6 in order to get Hadoop working.

Re: What's the status of IPv6 support?

[Eli Collins <el...@cloudera.com>]

On Friday, August 16, 2013, Steve Loughran wrote:

> On 16 August 2013 10:05, Andrew Pennebaker <apennebaker@42six.com<javascript:;>>
> wrote:
>
> > Thanks for the link!
> >
> > I understand a lack of support *for* IPv6, what I don't understand is why
> > IPv6 must be disabled in order for Hadoop to work. On systems with both
> > IPv4 and IPv6, I thought IPv4 apps could ignore IPv6 as if it weren't
> > available. I suppose that's not quite right.
> >
>
>
> historically the JVM IPv6 support on Linux has been pretty troublesome -I
> don't know if it's better now, because we all avoid it.
>
> I'm not sure you have to disable it as long as all java processes get
> started with "-Djava.net.preferIPv4Stack=true" as a JVM arg


That's correct, I've run Hadoop clusters with ipv6 enabled using these
options (they were checked in by default awhile back).



>
> If you don't say that then the JVM keeps trying to create sockets at the
> IPv6 level and then fallback to IPv4 if it can't connect, which adds
> overhead to all connections.
>
> -steve
>
>
> >
> > On Fri, Aug 16, 2013 at 12:44 PM, Eli Collins <eli@cloudera.com<javascript:;>>
> wrote:
> >
> > > Hey Andrew,
> > >
> > > I'm not aware of anyone working on IPv6 support.
> > >
> > > The following looks up to date and may be helpful:
> > > http://wiki.apache.org/hadoop/HadoopIPv6
> > >
> > > Thanks,
> > > Eli
> > >
> > > On Fri, Aug 16, 2013 at 8:27 AM, Andrew Pennebaker
> > > <apennebaker@42six.com <javascript:;>> wrote:
> > > > When will Hadoop get better IPv6 support? It would be nice if Ubuntu
> > > users
> > > > didn't have to disable IPv6 in order to get Hadoop working.
> > >
> >
>
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Re: What's the status of IPv6 support?

[Steve Loughran <st...@hortonworks.com>]

On 16 August 2013 10:05, Andrew Pennebaker <ap...@42six.com> wrote:

> Thanks for the link!
>
> I understand a lack of support *for* IPv6, what I don't understand is why
> IPv6 must be disabled in order for Hadoop to work. On systems with both
> IPv4 and IPv6, I thought IPv4 apps could ignore IPv6 as if it weren't
> available. I suppose that's not quite right.
>


historically the JVM IPv6 support on Linux has been pretty troublesome -I
don't know if it's better now, because we all avoid it.

I'm not sure you have to disable it as long as all java processes get
started with "-Djava.net.preferIPv4Stack=true" as a JVM arg

If you don't say that then the JVM keeps trying to create sockets at the
IPv6 level and then fallback to IPv4 if it can't connect, which adds
overhead to all connections.

-steve


>
> On Fri, Aug 16, 2013 at 12:44 PM, Eli Collins <el...@cloudera.com> wrote:
>
> > Hey Andrew,
> >
> > I'm not aware of anyone working on IPv6 support.
> >
> > The following looks up to date and may be helpful:
> > http://wiki.apache.org/hadoop/HadoopIPv6
> >
> > Thanks,
> > Eli
> >
> > On Fri, Aug 16, 2013 at 8:27 AM, Andrew Pennebaker
> > <ap...@42six.com> wrote:
> > > When will Hadoop get better IPv6 support? It would be nice if Ubuntu
> > users
> > > didn't have to disable IPv6 in order to get Hadoop working.
> >
>

-- 
CONFIDENTIALITY NOTICE
NOTICE: This message is intended for the use of the individual or entity to 
which it is addressed and may contain information that is confidential, 
privileged and exempt from disclosure under applicable law. If the reader 
of this message is not the intended recipient, you are hereby notified that 
any printing, copying, dissemination, distribution, disclosure or 
forwarding of this communication is strictly prohibited. If you have 
received this communication in error, please contact the sender immediately 
and delete it from your system. Thank You.

Re: What's the status of IPv6 support?

[Andrew Pennebaker <ap...@42six.com>]

Thanks for the link!

I understand a lack of support *for* IPv6, what I don't understand is why
IPv6 must be disabled in order for Hadoop to work. On systems with both
IPv4 and IPv6, I thought IPv4 apps could ignore IPv6 as if it weren't
available. I suppose that's not quite right.


On Fri, Aug 16, 2013 at 12:44 PM, Eli Collins <el...@cloudera.com> wrote:

> Hey Andrew,
>
> I'm not aware of anyone working on IPv6 support.
>
> The following looks up to date and may be helpful:
> http://wiki.apache.org/hadoop/HadoopIPv6
>
> Thanks,
> Eli
>
> On Fri, Aug 16, 2013 at 8:27 AM, Andrew Pennebaker
> <ap...@42six.com> wrote:
> > When will Hadoop get better IPv6 support? It would be nice if Ubuntu
> users
> > didn't have to disable IPv6 in order to get Hadoop working.
>

Re: What's the status of IPv6 support?

[Eli Collins <el...@cloudera.com>]

Hey Andrew,

I'm not aware of anyone working on IPv6 support.

The following looks up to date and may be helpful:
http://wiki.apache.org/hadoop/HadoopIPv6

Thanks,
Eli

On Fri, Aug 16, 2013 at 8:27 AM, Andrew Pennebaker
<ap...@42six.com> wrote:
> When will Hadoop get better IPv6 support? It would be nice if Ubuntu users
> didn't have to disable IPv6 in order to get Hadoop working.