[JDEV] scaling with jpolld (was JPOLLD)

[Oliver Jones]

At 08:00 PM 5/28/01 -0700, Kong Putra Yohanes wrote:
>I have set jabber server host name as digimon.com
>(that's my computer name's, before that i set to
>192.0.0.24) like this :
><host><jabberd:cmdline
>flag="h">digimon.com</jabberd:cmdline></host>

If I understand what you are saying, you want your Jabber users to connect 
to your server at digimon.com, and you want their Jabber identifiers to be 
like kong at digimon.com.

This means incoming client connect requests will be coming to digimon.com, 
port 5222.

So you must, as you write above, tell the jabberd server that its hostname 
is digimon.com.

Next, you have to contrive to get a program to listen to port 5222 on the 
machine whose IP address comes from looking up digimon.com.  That you can 
do with jpolld.

Third, if I understand you right, you are attempting to run jpolld and 
jabberd on the same machine.  That's fine, but you have to prevent jabberd 
from trying to listen to port 5222, or it will conflict with jpolld.

So, you'll want to run jpolld with a command line like this:

       jpolld -h 127.0.0.1 -d 5225 -n c2s -s test

This tells jpolld to initiate connection to jabberd at host:port 
127.0.0.1:5225.

Then, in jabber.xml (which needs to be named digmon.com.xml in your 
installation if you have things set up standard), you need to do two things.

1) make jabberd NOT listen on port 5222 for client connections.

2) make it listen on port 5225 for a jpolld connection.

To do the first of these things, remove this stanza from the XML file.
   <service id="c2s">
         ... yadda yadda yadda ...
   </service>

To do the second thing, add this stanza.  It tells jabberd to listen for a 
connection from a jpolld at 127.0.0.1:5225.

  <service id="c2s">
   <accept>
    <ip>127.0.0.1</ip>
    <secret>test</secret>
    <port>5225</port>
   </accept>
  </service>

Note well:  the jabberd software does NOT have to run on the same machine 
as jpolld, even though this example uses the localhost (127.0.0.1) IP 
number.  jpolld MUST be running on the machine whose name is digimon.com so 
users can connect, but jabberd can run anywhere.  Jabberd's configuration 
file should still tell jabberd that its server name is digimon.com, of course.

--------------------

Now, of course the point of jpolld is to let you run multiple 
jpollds.  This allows your jabber setup to accept larger number of 
connections.  You should plan for this I think (otherwise why mess about 
with jpolld at all? It just makes things more complex.)

The first part of your plan is to allocate a host name for your jabber 
server.  For example, jabber.digimon.com might be good in your case.

The second part is to get several different IP numbers to run the jpolld 
server on, and set up round robin DNS or some other load-distribution scheme.

The third part is to set up jabberd to run on a back-end machine; let's 
call that machine backend.digimon.com.  Suppose also that its IP number is 
192.168.1.1.

The fourth part is to run a separate jpolld on each server in the 
round-robin.  Here are the commands you'd use to run the two jpollds (one 
on each server).

       jpolld -h backend.digimon.com -d 6221 -n c2sa -s test
       jpolld -h backend.digimon.com -d 6222 -n c2sb -s test

The fifth part is to configure your XML file with these TWO stanzas, one 
for each jpolld.

  <!--  first jpolld -->
  <service id="c2sa">     <!-- service name matching jpolld's -n param -->
   <accept>
    <ip>192.168.1.1</ip>  <!-- IP matching jpolld's -h param -->
    <secret>test</secret> <!-- password matching jpolld's -s param -->
    <port>6221</port>     <!-- port matching jpolld's -d param -->
   </accept>
  </service>

  <!--  second jpolld -->
  <service id="c2sb">     <!-- service name matching jpolld's -n param -->
   <accept>
    <ip>192.168.1.1</ip>  <!-- IP matching jpolld's -h param -->
    <secret>test</secret> <!-- password matching jpolld's -s param -->
    <port>6222</port>     <!-- port matching jpolld's -d param -->
   </accept>
  </service>

-------------------------------

Take care that the jabberd starts before the jpollds.  If the jpollds can't 
find jabberd they will shut down right when they start.

--------------------------------

This should do the trick for you.  I got this working on March 29th, and my 
jabber setup has been running flawlessly since then and processed about a
quarter million messages.  I have seven jpollds talking to a single jabberd.

--------------------------------
You wrote:
>   <service id="c2s">
>     <host>jpolld.192.0.0.5</host>

Note your host name isn't valid here.  It isn't either a host name or an IP 
number.  Plus, you don't want to put a host name here anyhow.

>[1] Adding conn at 2
>[1] Max PFD: 2
>[1] Conn gone, mpfd: 1

This means your client connection is getting kicked out as soon as it 
arrives because of configuration errors.

Good luck!

Oliver Jones