[mythtv-users] Linux frontend database connection problems

[R. G. Newbury]

Piers Kittel wrote:
> Still have many woes with this... none of my Linux frontends will  
> connect to the backend - and I've moved the backend to new hardware,  
> still the same problem - OS X frontends doesn't have any problems,  
> but all Linux frontends cannot connect to the server - getting  
> extremely frustrated....  I even set up one computer and installed  
> the frontend on that... same problem...
> 
> I decided to do packet sniffing on one frontend, and found it sends  
> absolutely nothing to the backend at all... so it simply has to be a  
> local problem... but what?


Have you started at first principles?

Off the top of my head.

Can you cross ping between the machines?
Can you ssh from the frontends?  Needs /etc/host entries to be correct.
Can you nsf mount from the frontends? Needs stuff setup and running on 
the backend machine. If nsf works, then you have proved that all the 
required TCPIP is correct.

Now that leaves mysql access.
Make sure mysqld is OFF on each frontend and running on the backend.
Make sure that the mysql ports are open.  Fedora has a little program 
called 'lokkit' which is made for port opening/checking.

The backend needs a unique name/IP. Set it in each frontend in 
/etc/hosts. DHCP is a real problem here: use static IP addresses.
Mythtv-setup on the backend cannot use 127.0.0.1 !!!
At this point you should be able to ssh into the back from the fronts 
and vice versa. If you set up nfs then you should be able to mount the 
storage partition from the frontends.

Create a mysql user for each frontend machine by amending and re-running 
the mc.sql script which is in mythtv/database.
....(I'm not sure if mysql will work from multiple frontends using the 
same mysql user.)

At this point, running 'select host,user,password from user;' on the 
mysqld server (backend) machine, as root mysql user should list the 
various frontend machines by name, the mysql users and show the hash of 
the password. At this point you should be able to log into the mysql 
server from each frontend and run mysql queries as the frontend's user 
and as the root mysql user. If you cannot do this, myth will not be able 
to either.....

Run 'find' to check for duplicate copies of mysql.txt on each machine.
Fix the /home/mythtv frontend copy of mysql.txt to refer to the correct 
backend IP addess and the frontend mysql user name.
Cross your fingers.
Call your local witchdoctor about having the goat sacrificed *properly*...
Try, try again.


And remember:
If at first you don't succeed, sky-diving is nor recommended.

HTH

Geoff