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Re: Picking an unused port number

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On 6/7/2016 09:28, Nigel Wade wrote:
> On 07/06/16 15:43, Knute Johnson wrote:
>> On 6/7/2016 01:43, Nigel Wade wrote:
>>> On 06/06/16 23:40, Knute Johnson wrote:
>>>> Any port works until there is a conflict.  It's what you do about it
>>>> then that separates the easy from the hard.
>>>>
>>>
>>> The best way to avoid conflicts is to allow the system to give you an
>>> unallocated port and then register that port using some method such as
>>> rpcbind, or in the Java world, rmiregistry. These two methods are
>>> primarily for registering remote procedures/methods, but can also be
>>> used for simply registering an assigned port to provide a named service.
>>>
>>> A client can query portmap or rmiregistry to find out what port a
>>> particular service is registered, and listening, on.
>>> The only port numbers which then need to be well defined are those used
>>> by portmap or rmiregistry. rpcbind/portmap is required by NFS and NIS
>>> (formerly YP). I use rmiregistry with some of my applications where I
>>> need to operate a server but don't wish to define a fixed port number
>>> (to avoid possible future conflicts).
>>>
>>
>> Nigel
>>
>> Do you know where I can get more detailed information on how to do
>> that?  I've never played with rmiregistry.
>>
>
> http://docs.oracle.com/javase/tutorial/rmi/index.html
> is a good place to start.
>
> This FAQ is something I used to use. The Java version does indicate how
> long ago it was that I last programmed RMI,
> http://docs.oracle.com/javase/1.5.0/docs/guide/rmi/faq.html#netcontact
> The code I have was mostly written in Java 1.4, so it's a bit out of date.
>
> In essence, RMI allows you to invoke remote methods on a server without
> having to worry about Sockets and ports and the low level nastiness
> normally associated with client/server communication. You declare your
> methods, parameters and return result as normal. The low level socket
> creation, object serialisation/deserialisation and method invocation is
> all taken care of for you.
>
> An RMI server extends some implementation of Remote, and registers it
> with rmiregistry using Naming or Registry bind/rebind methods. A client
> wishing to invoke remote methods on the server uses the Naming or
> Registry lookup method to locate the server, and receives a copy of the
> Remote object. The methods in the Remote object can be invoked just as
> if they were methods in a local class in the same JVM. I can't offhand
> remember why there is the duplication of Naming, Registry and
> LocateRegistry.
>
> It's not entirely as simple as that, but it's essentially all there is
> to it. Apart from classpaths, and locating the classes. That can be a
> bit more interesting, especially for the rmiregistry.
>
>

Thanks Nigel!

-- 

Knute Johnson

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Re: Picking an unused port number nathanturner369@gmail.com - 2016-06-04 08:24 -0700
  Re: Picking an unused port number Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2016-06-04 09:56 -0700
    Re: Picking an unused port number Eric Douglas <e.d.programmer@gmail.com> - 2016-06-06 05:28 -0700
      Re: Picking an unused port number Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2016-06-06 15:40 -0700
        Re: Picking an unused port number Nigel Wade <nmw@ion.le.ac.uk> - 2016-06-07 09:43 +0100
          Re: Picking an unused port number Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2016-06-07 07:43 -0700
            Re: Picking an unused port number Nigel Wade <nmw@ion.le.ac.uk> - 2016-06-07 17:28 +0100
              Re: Picking an unused port number Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2016-06-07 09:40 -0700
                Re: Picking an unused port number Nigel Wade <nmw@ion.le.ac.uk> - 2016-06-08 10:32 +0100
                Re: Picking an unused port number Eric Douglas <e.d.programmer@gmail.com> - 2016-06-08 06:45 -0700
                Re: Picking an unused port number Nigel Wade <nmw@ion.le.ac.uk> - 2016-06-08 15:06 +0100
                Re: Picking an unused port number Eric Douglas <e.d.programmer@gmail.com> - 2016-06-08 07:36 -0700
                Re: Picking an unused port number Martin Gregorie <martin@address-in-sig.invalid> - 2016-06-08 18:03 +0000
  Re: Picking an unused port number Jerry Stuckle <jstucklex@attglobal.net> - 2016-06-04 20:50 -0400
    Re: Picking an unused port number Wayne <wayne@nospam.invalid> - 2016-06-06 18:44 -0400
      Re: Picking an unused port number Jerry Stuckle <jstucklex@attglobal.net> - 2016-06-06 20:52 -0400
        Re: Picking an unused port number Arne Vajhøj <arne@vajhoej.dk> - 2016-06-06 21:28 -0400
          Re: Picking an unused port number Jerry Stuckle <jstucklex@attglobal.net> - 2016-06-06 21:45 -0400
            Re: Picking an unused port number Arne Vajhøj <arne@vajhoej.dk> - 2016-06-06 23:07 -0400
              Re: Picking an unused port number Jerry Stuckle <jstucklex@attglobal.net> - 2016-06-07 09:50 -0400
                Re: Picking an unused port number Lew <lewbloch@gmail.com> - 2016-06-07 13:46 -0700
                Re: Picking an unused port number Jerry Stuckle <jstucklex@attglobal.net> - 2016-06-07 19:31 -0400
                Re: Picking an unused port number Lew <lewbloch@gmail.com> - 2016-06-07 17:26 -0700
                Re: Picking an unused port number Jerry Stuckle <jstucklex@attglobal.net> - 2016-06-07 21:34 -0400
                Re: Picking an unused port number Lew <lewbloch@gmail.com> - 2016-06-08 13:52 -0700
                Re: Picking an unused port number Jerry Stuckle <jstucklex@attglobal.net> - 2016-06-08 17:49 -0400
                Re: Picking an unused port number Arne Vajhøj <arne@vajhoej.dk> - 2016-06-07 21:53 -0400
        Re: Picking an unused port number a.laforgia@gmail.com - 2016-06-07 00:11 -0700

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