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From tommy xiao <xia...@gmail.com>
Subject Re: LIBPROCSES_IP
Date Sat, 15 Oct 2016 23:01:39 GMT
good point, +1

2016-10-13 0:27 GMT+08:00 Jie Yu <yujie.jay@gmail.com>:

> Stephan,
>
> I think the only time the framework needs to set LIBPROCESS_ADVERTISE_IP is
> when DNAT is necessary for the container (e.g., bridge). In that
> case, LIBPROCESS_ADVERTISE_IP should always be agent ip and
> the relevant host port allocated for the container. For other cases,
> framework should not do anything.
>
> - Jie
>
> On Wed, Oct 12, 2016 at 4:43 AM, Erb, Stephan <Stephan.Erb@blue-yonder.com
> >
> wrote:
>
> > >Framework should be the one that sets
> > >LIBPROCESS_ADVERTISE_IP and LIBPROCESS_ADVERTISE_PORT appropriately if
> it
> > >tries to launch another Mesos framework so that Master can reach the new
> > >framework.
> >
> > As a framework/executor author this is not possible in all scenarios:
> > There is no way to discover IP addresses assigned via CNI before the
> first
> > StatusUpdate has been received. It is therefore not possible to set
> > LIBPROCESS_ADVERTISE_IP appropriately at launch time.
> >
> > Please see https://issues.apache.org/jira/browse/MESOS-6281 for details.
> >
> >
> > On 12/10/16 06:42, "Avinash Sridharan" <avinash@mesosphere.io> wrote:
> >
> >     Valid point. Makes sense to drive this decision from the user and the
> >     framework.
> >
> >     On Tue, Oct 11, 2016 at 9:32 PM, Jie Yu <yujie.jay@gmail.com> wrote:
> >
> >     > >
> >     > > While I believe this particular logic of setting
> > LIBPROCESS_ADVERTISE_IP
> >     > > to agent IP can be done in the agent (it could look at the port
> > mapping
> >     > > as well)
> >     >
> >     >
> >     > What if there are multiple port mappings? How can the agent decide
> > which
> >     > port to be used as  LIBPROCESS_ADVERTISE_PORT?
> >     >
> >     > On Tue, Oct 11, 2016 at 9:27 PM, Avinash Sridharan <
> > avinash@mesosphere.io>
> >     > wrote:
> >     >
> >     > > Definitely a +1 for executor binding to 0.0.0.0, instead of
> doing a
> >     > > `gethostname` and `getaddrinfo`. But I am assuming this semantics
> > would
> >     > > kick in only if LIBPROCESS_IP is not set, which should be the
> norm.
> >     > >
> >     > > +1 for LIBPROCESS_ADVERTISE_IP and LIBPROCESS_ADVERTISE_PORT and
> > the onus
> >     > > being on the frameworks to set these variables. I guess the
> > framework can
> >     > > set the LIBPROCESS_ADVERTISE_IP to the agent IP and
> >     > > LIBPROCESS_ADVERTISE_PORT to the host port when it specifies a
> >     > > port-mapping. While I believe this particular logic of
> >     > > setting LIBPROCESS_ADVERTISE_IP to agent IP can be done in the
> > agent (it
> >     > > could look at the port mapping as well), when to actually set
> these
> >     > > variables (whether the executors even need to advertise their IP
> >     > addresses,
> >     > > is a decision that the Frameworks should be privy too and not
> left
> > to the
> >     > > agent.
> >     > >
> >     > > On Tue, Oct 11, 2016 at 7:31 PM, haosdent <haosdent@gmail.com>
> > wrote:
> >     > >
> >     > > > > libprocess should always bind to 0.0.0.0
> >     > > > + 1 for this
> >     > > >
> >     > > > On Wed, Oct 12, 2016 at 2:33 AM, Jie Yu <yujie.jay@gmail.com>
> > wrote:
> >     > > >
> >     > > > > Hi folks,
> >     > > > >
> >     > > > > I was in the process of cleaning up some tech debt related
to
> > env
> >     > > > variables
> >     > > > > in our code base. I created an epic ticket
> >     > > > > <https://issues.apache.org/jira/browse/MESOS-6341>
to
> track. I
> >     > > searched
> >     > > > > relevant tickets fired previously, and found MESOS-3740
> >     > > > > <https://issues.apache.org/jira/browse/MESOS-3740>.
I did
> some
> >     > digging
> >     > > > on
> >     > > > > how we handle LIBPROCESS_IP currently, and here are my
> > findings:
> >     > > > >
> >     > > > > 1) We always set LIBPROCESS_IP in the executor environment
> > variables:
> >     > > > > https://github.com/apache/mesos/blob/master/src/slave/
> >     > > > > slave.cpp#L6793-L6796
> >     > > > >
> >     > > > > This is not an issue for an executor that runs on host
> network.
> >     > > However,
> >     > > > if
> >     > > > > the executor wants to run on non-host network (e.g.,
> overlay),
> > this
> >     > > might
> >     > > > > be problematic, because libprocess for the executor will
try
> > to bind
> >     > to
> >     > > > > LIBPROCESS_IP, but the IP is not valid inside the container.
> >     > > > >
> >     > > > > 2) As mentioned in MESOS-3740
> >     > > > > <https://issues.apache.org/jira/browse/MESOS-3740>,
some
> user
> > wants
> >     > to
> >     > > > run
> >     > > > > a Mesos framework in a Mesos container. The old style
> framework
> >     > driver
> >     > > > > assumes a 2 way communication channel between the framework
> > and the
> >     > > Mesos
> >     > > > > master. In order for the master to reach the framework
> running
> >     > inside a
> >     > > > > Mesos container, the framework's libprocess should advertise
> > its ip
> >     > and
> >     > > > > port properly. This problem gets tricky because the
> networking
> > for
> >     > the
> >     > > > > Mesos container:
> >     > > > >
> >     > > > > 2.a) If the container uses host network, libprocess should
> > bind to
> >     > > > 0.0.0.0,
> >     > > > > and advertise itself using the agent ip and the relevant
port
> >     > > > > 2.b) If the container has a routable ip (e.g., using calico
> or
> >     > > overlay),
> >     > > > > libprocess should still bind to 0.0.0.0, and advertise itself
> > using
> >     > the
> >     > > > > container ip and the relevant port. Currently, it binds
to
> > agent ip
> >     > > > (which
> >     > > > > will fail), and advertise itself using agnet ip and the
port
> > in the
> >     > > > > container (which will fail as well)
> >     > > > > 2.c) If the container has a private ip (e.g., bridge),
> > libprocess
> >     > > should
> >     > > > > still bind to 0.0.0.0, and advertise itself using the agent
> ip
> > and
> >     > > > _mapped_
> >     > > > > host port. Currently, it binds to agent ip (which will fail),
> > and
> >     > > > advertise
> >     > > > > itself using agent ip and the port in the container (which
> > will fail
> >     > as
> >     > > > > well)
> >     > > > >
> >     > > > > Therefore, the workaround
> >     > > > > <https://github.com/mesosphere/mesos/commit/
> >     > > > b9c622b53b3ffcc27911fcdcefc37a
> >     > > > > 52ebe33bdd>
> >     > > > > suggested in MESOS-3740 <https://issues.apache.org/
> >     > > > jira/browse/MESOS-3740>
> >     > > > > is not ideal. It does not consider 2.b) and 2.c)
> >     > > > >
> >     > > > > Libprocess now supports both LIBPROCESS_IP and
> >     > LIBPROCESS_ADVERTISE_IP
> >     > > so
> >     > > > > the bind address does not have to be the address that is
> being
> >     > > > advertised.
> >     > > > >
> >     > > > > For the 2.c) case, Mesos don't have a way to determine the
> > advertise
> >     > > port
> >     > > > > (mapped port). This information is only known to the
> framework
> > (which
> >     > > > host
> >     > > > > port it'll use to serve as the mapped port for the
> libprocess).
> >     > > > >
> >     > > > > Given that, I think Mesos should not bindly set LIBPROCESS_IP
> > to
> >     > agent
> >     > > IP
> >     > > > > in executor environment variables. Framework should be the
> one
> > that
> >     > > sets
> >     > > > > LIBPROCESS_ADVERTISE_IP and LIBPROCESS_ADVERTISE_PORT
> > appropriately
> >     > if
> >     > > it
> >     > > > > tries to launch another Mesos framework so that Master can
> > reach the
> >     > > new
> >     > > > > framework. If the framework just wants to launch a regular
> > container
> >     > > that
> >     > > > > does not depends on libprocess, it should simply not set
> these
> > env
> >     > > > > variables.
> >     > > > >
> >     > > > > Also, I think libprocess should always bind to 0.0.0.0,
> rather
> > than
> >     > > > doing a
> >     > > > > hostname lookup and bind to the IP found for the hostname.
> >     > > > > LIBPROCESS_ADVERTISE_IP can be used to overwrite the ip
> > address it
> >     > > wants
> >     > > > to
> >     > > > > advertise to peers. If that's not specified, it'll try to
do
> a
> >     > hostname
> >     > > > > lookup to guess a routable ip.
> >     > > > >
> >     > > > > Thoughts?
> >     > > > > - Jie
> >     > > > >
> >     > > >
> >     > > >
> >     > > >
> >     > > > --
> >     > > > Best Regards,
> >     > > > Haosdent Huang
> >     > > >
> >     > >
> >     > >
> >     > >
> >     > > --
> >     > > Avinash Sridharan, Mesosphere
> >     > > +1 (323) 702 5245
> >     > >
> >     >
> >
> >
> >
> >     --
> >     Avinash Sridharan, Mesosphere
> >     +1 (323) 702 5245
> >
> >
> >
> >
>



-- 
Deshi Xiao
Twitter: xds2000
E-mail: xiaods(AT)gmail.com

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