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<DIV><FONT face=Arial size=2>You may achieve this using following
steps:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1) Open your local host file -- for windows
that would be under C:\WINDOWS\system32\drivers\etc\hosts (make sure that you're
using the right HOSTS file)</FONT></DIV>
<DIV><FONT face=Arial size=2>2) Add an alias to the localhost and save
changes i.e.</FONT></DIV>
<DIV><FONT face=Arial size=2>
127.0.0.1 localhost theErlangHost</FONT></DIV>
<DIV><FONT face=Arial size=2>3) Start erlang using:</FONT></DIV>
<DIV><FONT face=Arial size=2> erl -sname <A
href="mailto:node1@theErlangHost">node1@theErlangHost</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>This will force any other local erlang node to
connect using 127.0.0.1</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>In order to allow remote nodes to connect as well,
you would need to configure remote host file like this:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>192.168.0.30 theErlangHost</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>which will allow remote nodes to come in using the
LAN interface.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>EXPLANATION:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>If you run command "epmd -names" the epmd
will return list of names and associated port numbers, for example:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>epmd: up and running on port 4369 with
data:<BR>name node1 at port 3527<BR>name node2 at port
3513</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>If you then go and chack the listeners for these
ports, you're likely to find something like this:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>TCP
0.0.0.0:3513
0.0.0.0:0
LISTENING</FONT></DIV>
<DIV>
<DIV><FONT face=Arial size=2>TCP
0.0.0.0:3527
0.0.0.0:0
LISTENING</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>This means that transport layer supports any
available incoming interface, thus everything is in address
resolution:</FONT></DIV>
<DIV><FONT face=Arial size=2>Local node will resolve theErlangHost as 127.0.0.1,
whislt remote shall use 192.168.0.30.</FONT></DIV>
<DIV><FONT face=Arial size=2>The important thing is to keep the symbolic host
name the same, as it is used by net-kernel. (It is interesting though, that
hidden C-nodes are not required to use the symbolic host names -- plain IP
address does the trick).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The same is true for other operating systems as
well.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Tell me if this makes any sense to
you.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Valentin.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>PS</FONT></DIV>
<DIV><FONT face=Arial size=2>Funny thing is that I've been discussing similar
(yet completely different thing) with Francesco yesterday, and he
suggested startup syntax erl -sname <A
href="mailto:sys@Host">sys@Host</A>.</FONT></DIV>
<DIV><FONT face=Arial size=2>It did not help me solve my problem -- no
matter what I've tried it resulted in failure. However, the consequences of
these failure is the above -- I'd be very pleased if it can help
you.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>BTW: anybody knows how to force a single erlang
run-time to support two, or more internal hostnames, i.e.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>If I have two interfaces:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>10.0.0.2
host_private</FONT></DIV>
<DIV><FONT face=Arial size=2>198.1.2.3 host_public</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>How can I start node1 in such a way that both
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>rpc:call( <A
href="mailto:'node1@host_private'">'node1@host_private'</A>, os, type,
[]).</FONT></DIV>
<DIV><FONT face=Arial size=2>and</FONT></DIV>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>rpc:call( <A
href="mailto:'node1@host_public'">'node1@host_public'</A>, os, type,
[]).</FONT></DIV>
<DIV> </DIV>
<DIV>connect to the same node1?</DIV>
<DIV> </DIV>
<DIV> </DIV></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> </FONT></DIV></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=erlang@inswitch.us href="mailto:erlang@inswitch.us">Inswitch
Solutions - Erlang Evaluation</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=erlang-questions@erlang.org
href="mailto:erlang-questions@erlang.org">erlang-questions@erlang.org</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, October 01, 2004 2:36
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Linking two Pids of nodes
that are in the same machine - noconnection signal!</DIV>
<DIV><FONT face=Arial size=2></FONT><FONT face=Arial size=2></FONT><FONT
face=Arial size=2></FONT><FONT face=Arial size=2></FONT><FONT face=Arial
size=2></FONT><FONT face=Arial size=2></FONT><BR></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I'll try to explain the problem from
another point of view.</FONT></DIV>
<DIV><FONT face=Arial size=2>The machine I'm using is named design
(IP=192.168.0.30).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>In Windows 2000:</FONT></DIV>
<DIV><FONT face=Arial size=2>With LAN cable disconnected:</FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2>ping design</FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2>Response from <FONT
color=#ff0000>127.0.0.1</FONT>: bytes=32 tieme<10ms
TTL=128<BR></FONT></DIV>
<DIV><FONT face=Arial size=2>With LAN cable connected:</DIV></FONT>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial color=#0000ff size=2>ping design</FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2>Response from <FONT
color=#ff0000>192.168.0.30</FONT>: bytes=32 tieme<10ms
TTL=128<BR></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><FONT
color=#000000></FONT> </DIV></FONT>
<DIV><FONT face=Arial size=2>Having two Erlang nodes in the same machine the
TCP socket connections are different:</FONT></DIV>
<DIV>1- if LAN cable disconnected the connection between nodes is
established using 127.0.0.1:PORT </DIV>
<DIV>
<DIV>2- if LAN cable connected the connection between nodes is
established using 192.168.0.30:PORT</DIV>
<DIV> </DIV>
<DIV>The problem is that in situation 2) and then if the LAN cable
is disconnected the connections established with 192.168.0.30:PORT are lost.
This can be also verified when "ping design" in W2000 command
prompt.</DIV>
<DIV> </DIV>
<DIV>- Can I force Erlang to use 127.0.0.1 for local nodes connection instead
of 192.168.0.30 ?</DIV></DIV>
<DIV>
<DIV>- How can I solve this problem so not to lose local connections in
any case?</DIV>
<DIV>- Does the same behaviour happen in other OS?</DIV></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>thanks in advance,</FONT></DIV>
<DIV><FONT face=Arial size=2>Eduardo Figoli</FONT></DIV>
<DIV><FONT face=Arial size=2>INSwitch Solutions</FONT></DIV>
<DIV><FONT face=Arial size=2> </DIV></FONT></FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=erlang@inswitch.us href="mailto:erlang@inswitch.us">Inswitch
Solutions - Erlang Evaluation</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=erlang-questions@erlang.org
href="mailto:erlang-questions@erlang.org">erlang-questions@erlang.org</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, September 30, 2004
10:46 AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Linking two Pids of nodes that
are in the same machine - noconnection signal!</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The attached code links to pids of nodes
that are in the same machine and I don't know why I receive a noconnection
signal when the LAN cable is disconnected. This does no happen when running
the code with the LAN cable disconnected and connecting/disconnecting it
later.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>If someone wants to give a try, I send a
code to test this situation and y</FONT><FONT face=Arial size=2>ou
should modify on node1.erl the blue text line below:</FONT></DIV>
<DIV><FONT face=Arial size=2>{node2Pid, <FONT
color=#0000ff>node2@design</FONT>} ! {self()},</FONT></DIV>
<DIV><FONT face=Arial size=2>with the corresponding machine name where you
will run it</FONT><FONT face=Arial size=2>.</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2><STRONG>On the same machine do the
following:</STRONG></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>1 - "erl -sname node2"</FONT></DIV>
<DIV><FONT face=Arial size=2>2 - "node2:start()."</FONT></DIV>
<DIV> </DIV></FONT></DIV>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>2 - "erl -sname node1"</FONT></DIV>
<DIV><FONT face=Arial size=2>3 - "node1:start()."</FONT></DIV></FONT><FONT
face=Arial size=2> </FONT></DIV>
<DIV><FONT face=Arial size=2>4 - The pid is linked and a message is
shown on node1.</FONT></DIV>
<DIV><FONT face=Arial size=2>5 - node2Pid shows a message every 1 sec while
checking the queue message</FONT></DIV>
<DIV><FONT face=Arial size=2>6 - node1 process loops checking the queue
message </FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>7 - Disconnect LAN cable</FONT></DIV>
<DIV><FONT face=Arial color=#ff0000 size=2>8 - node2Pid receives a
noconnection signal</FONT></DIV>
<DIV><FONT face=Arial color=#ff0000 size=2>9 - node1 process receives an
{'EXIT',Pid,noconnection}</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>- When linking Pids of different nodes that are
in the same machine why do I receive a "noconnection" signal?</FONT></DIV>
<DIV><FONT face=Arial size=2>- Having the LAN cable disconnected
and doing steps 1..6 8..9, if I connect/disconnect the LAN cable the
"noconnection" signal is never received (correct behaviour). </FONT></DIV>
<DIV><FONT face=Arial size=2>- If in the source code I do not use
"process_flag(trap_exit, true)," the processes </FONT><FONT
face=Arial size=2>terminate, why is this happenning as no kill signal is
sent?</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>thanks in advance,</FONT></DIV>
<DIV><FONT face=Arial size=2>Eduardo Figoli</FONT></DIV>
<DIV><FONT face=Arial size=2>INSwitch Solutions</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
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