View source for Flux multi-user server

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== Definition ==

Flux multi-user server (alis Hydra) is ''Open Virtual Worlds Web Server'' made by [http://www.mediamachines.com/ Media Machines]. Currently in alpha/early beta - 19:33, 6 July 2007 (MEST)

For the moment, this page is only of interest to ''technical'' folks. Hydra is not ready for the masses on July 2007.

== Installation ==

[[User:Daniel K. Schneider|Daniel K. Schneider]] tried on his personal Linux Desktop (Ubuntu 6.10). Disclaimer: I am not a programmer nor a sysadmin. Also, I use root to do command-line installations (can't get myself to type sudo in repetition).

=== Downlods ===

# Get the [http://www.hawksoft.com/hawknl/  Hawk Network Library version 1.7 by Phil Frisbie] (LGPL). You can find it in the downloads section.
# Get [http://www.mediamachines.com/hydra/ Hydra], Flux Multi-User
# Get MySQL development libraries and MySQL is you don't have these (see below)
# Also install [http://www.mediamachines.com/make.php Flux Player 2.1] if you don't have it already.

=== Preparation of installation ===

; MySQL

* Install MySQL '''and''' the development libararies !
* Use Synaptic Package Manger or apt-get and install these
I took:
 mysql-server
 libmysqlclient15-dev

If don't want to type command-lines to mysql, you also may want to install a mysql administration client. I tried (but then only used it to change the root password of the mysql server).
 mysqladmin

This tool then will show up under Applications/Systems tools. First time you connect you can use 'root' without password.

Then, open a terminal and become root:
 su

; Hydras (files)
Currently (July 2007) you have to compile Hydras and HawkNL it yourself. 

* unzip into a folder, e.g. I used
 /usr/local/flux/hydra

; Modify some source code

* I suggest to make a change to scenemodel.c (else you will have to use database, user and password for MySQL... Change line 51 from:
 (&hydra_db, "localhost", "user", "password", "database", 0, NULL, 0) != NULL);
to:
  (&hydra_db, "localhost", "hydrausr", "SECRET", "hydra", 0, NULL, 0) != NULL);

* Edit hydras.c, i.e. replace
 char *url = "http://worlds.webers.org/content/testbed/";
by something of your own

; HawkNL

* Put it in a folder named "HawkNL" at the same level as the folder containing the Hydra sources. E.g. I used 
 /usr/local/flux/HawkNL

  unzip HawkNL17b1src.zip [-d "flux directory"]
  cd "flux directory"
  ln -s HawkNL1.70 HawkNL

; Result is something like this

 /usr/local/flux
 lrwxrwxrwx  1 root root   10 2007-07-06 15:28 HawkNL -> HawkNL1.70
 drwxr-xr-x  7 root root 4096 2007-07-06 15:27 HawkNL1.70
 drwxr-xr-x  2 root root 4096 2007-07-06 15:40 hydra
 drwxr-xr-x  2 root root 4096 2007-07-06 15:39 src

=== Compilation ===

; HawNL

  cd HawkNL
  make -f makefile.linux
  make -f makefile.linux install

It will also copy the libraries in /usr/local/lib and header to  /usr/local/include/nl.h

; Hydras

* On Windows, load the hydras.sln or hydrac.sln solution files into MSVC 2003 or later (not tested)
* On Linux (I used Ubuntu) run make on the Makefile with gcc installed.

 cd hydra
 make

Result:
 gcc -I/usr/include/mysql -DUSE_MYSQL -c scenemodel.c
 gcc -I/usr/include/mysql -DUSE_MYSQL -c netcontroller.c
 gcc -c netview.c
 gcc -c -ggdb swamp.c
 gcc -o hydras -pthread hydras.o clients.o scenemodel.o netcontroller.o  netview.o swamp.o ../HawkNL/src/libNL.a -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient
 gcc -c -ggdb hydrac.c
 gcc -o hydrac -pthread hydrac.o swamp.o ../HawkNL/src/libNL.a
 hydrac.o: In function `printErrorExit':
 /usr/local/flux/hydra/hydrac.c:76: warning: the `gets' function is dangerous and should not be used.
 make: *** No rule to make target `hydrabot', needed by `all'.  Stop.

This doesn't seem to be harmful (for the moment) since hydras (the server) is built.

=== MySQL database ===

I presuppose that both MySQL and your Hydra will run on the same machine.

; Create a hydra database and a user (same as in scenemodel.c)

I used the command line since I couldn't figure out how to use the GUI ;)
 mysql -p

* You have to create a hydra_db databse called <code>hydra</code>

 mysql> create database hydra;

* Then create the user called hydrausr (change secret of course)

 mysql> create user hydrausr identified by 'secret';

* Then give it rights to the hydra database
 mysql > GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP ON hydra.* TO 'hydrausr'@'localhost';

* Then reload the privileges
 mysql > flush privileges;

; Create a User table
This is needed for avatars, else you get something like:
 Client connected with yourid=1, mytoken=/MM-6-12345678, uid=6
 SELECT login_name,avatar FROM users WHERE uid=6
 wrote 61 bytes to 1
 Segmentation fault (core dumped)

So you go:

 mysql -p
 use hydra
Copy/paste this:
 CREATE TABLE `users` (
 `login_name` varchar(32) default NULL,
 `password_hash` varchar(128) default NULL,
 `uid` int(10) unsigned NOT NULL auto_increment,
 `avatar` varchar(128) default NULL,
 `email` varchar(255) default NULL,
 `iconurl` varchar(255) default '/users/media/defaulticon.jpg',
 terms smallint unsigned default 0, /* signifies which terms user agreed to, should  always be > 0 */
 mailings smallint unsigned default 0, /* signifies the level of mailings user agreed to,  0 is only essential */
 PRIMARY KEY (`uid`)
 );

To check it:
 mysqlshow hydra -p
 Enter password: 
 Database: hydra
 +--------+
 | Tables |
 +--------+
 | users  |
 +--------+

 mysqlshow hydra users -p
 .....
 
=== Run it to test if it may work ===

Type: hypdras
 ./hydras

You may see:
 port is 13214
 url is http://tecfa.unige.ch/guides/x3d/ex/hydra/testbed.html
 connected to database
 Listening on 13214

Note: if you didn't edit the *.c files as told above, you will get
  url is http://worlds.webers.org/content/testbed/

From another terminal you also may launch a text client.
 ./hydrac -d
You may see:
 read 4 bytes, messlen is 6
 read 6 bytes, messlen is 6
 hello yourid=0, mytoken=NA

... though I can't figure out how one could use this to test other things.

=== Run it with your own stuff ===

To test, get the [http://www.mediamachines.com/source/fluxmutests.zip Flux Multi-user test files] from [http://www.mediamachines.com/hydra/ media machines] and dezip on some webserver.

Then edit files localplane.x3d and testbed.x3d etc. and change from:
  url="'swmp://localhost:13214/MM-6-12345678'"/>
to the URL of your Hydra server (not the webserver !)

The try with a Flux Player. E.g. enter a URL like
 http://tecfa.unige.ch/guides/x3d/ex/hydra/localplane.html
 http://tecfa.unige.ch/guides/x3d/ex/hydra/testbed.html

Note: The hydra URL runs on my desktop and will be mostly down ... So don't bet on the files / server I installed.

If you correctly created the MySQL ''users'' table you'll see something like:
 ./hydras -d
 port is 13214
 url is http://tecfa.unige.ch/guides/x3d/ex/hydra/testbed.html
 connected to database
 Listening on 13214
 Client connected from 129.194.112.101:1032 on socket 1
 read 18 bytes from 1
 wrote 6 bytes to 1
 Client connected with yourid=1, mytoken=/MM-6-12345678, uid=6
 SELECT login_name,avatar FROM users WHERE uid=6
 wrote 61 bytes to 1
 read 35 bytes from 1
 read 35 bytes from 1
 read 35 bytes from 1
 .....

=== Conclusion ===

I think I got it working somewhat. But the test scene has missing files and is sluggish (even on a good Dell XPS II LapTop). I seem to wake up in the middle of an avatar etc. At some point I think I have seen 2 avatars, but it may have been a Fata Morgana.

Maybe something to do with client stuff like avatars being identical from 2 different machines or so .... will look at it again at some point. Maybe something not correctly installed.

== Links ==

; Mediamachines
* http://www.mediamachines.com/
* [http://www.mediamachines.com/hydra/ Flux Multi-User] ('''essential''' reading)


; Help for installation

* [http://planet-earth.org/smam/fluxServerInstallRun.html Experience installing, compiling and running Flux server and client] by DragonMage, really useful !
* [http://community.mediamachines.com/categories.php Developer Forums]

[[Category: Technologies]]
[[Category: Virtual environments]]