Web, Email & MySQL Database Cluster : server2 doesn't handle DNS

Hi all,

Well I've setup (4 years ago) a configuration similar to this one : https://www.howtoforge.com/tutorial...abase-cluster-on-debian-8.4-with-ispconfig-3/
(except that I was using unison instead of Dovecot to sync emails)

Databases, emails and sites were all well synched on server2.
server1 turned out to be offline.

Bad thing is that all DNS zones were assigned to server1 in ISPConfig (on server2), ie :
Client Server Zone NS Email
client1 server1.domain.tld zone1.tld ns1.zone1.tld. [email protected].
client2 server1.domain.tld zone2.tld ns1.zone2.tld. [email protected].
So I was able to change the DNS values, but they were assigned to server1 (offline).
There is no DNS inputs for server2.domain.tld

Is that a normal case ?
I had to manually edit every bind zone file to make DNS working (and stopping ISPConfig cronjob that would revert changes)
Thanks a lot for your time.

 

Hi,
Thanks for your answer !
I know that a failover IP would be the best way (but in this case the 2 servers are not hired by the same companies, so I can't share an IP between them).
What hurts me is that (now that server1 is offline) when I connect to server2 ISPConfig GUI, DNS :
All listed zones are assigned to server1.domain.tld and there isn't any other option (server2.domain.tld) in the 'server' dropdown list.
I thought I could simply assign all zones to server2 and update the DNS entries (via the API).

 

That is what I have done, but changes are NOT applied to server2 ....
Basically nearly all DNS sites input (A) were pointing to server1 IP.
When server1 has gone offline, I ran the API script I wrote to update all DNS sites entries to server2 IP.
But server2 bind files are NOT modified.

 

In a cluster setup, each server has its own database :
server1 -> dbispconfig1
server2 -> dbispconfig2
in this case : server2 has only access to dbispconfig1 database (server1 one, that if offline)
I'm in a hurry to make this setup working again, I'll keep you informed

 

Are you trying to fix A record (the ip address) replicated in server 2 to server 2 ip?

A script to search and replace plus a dns resync afterwards seems the only way to do so.

 

Hi,
Yes, that's what my script is doing.
Bad thing is that server2 only has access (from Ispconfig GUI) to server1 database.

 

If you run a mirror-setup, the slave-servers are always excluded from the server-list.

 

Good if you already have the script ready for that. I hope you can share the script and/or its how to.

No sure about the ISPConfig Control Panel access, but I think server1 mainly accesses dbispconfig1 and server2 mainly accesses dbispconfig2, and they are both available in both servers (automatically resynced and updated if both are working); so you may just need to enable ISPConfig control panel (GUI) from server2 in case server1 cannot be accessed?

 

Thanks Florian and Till for your answers.
Yes that's a mirror-setup (server2 is mirror of server1).
Server1 is offline.
Server2 can only access server1 database.
So it is impossible to make any change via Ispconfig GUI on server2 ...
Is it a normal case ?

 

It requires a bit time reading the API doc, I'll post it later (on phone right now) .

 

OK Till, thanks for for explanation.
And what about master server can't be up again ?
Is there any possible master-master solution ?

 

In this particular case (Master won't be online) :
Will a simple untick 'is a mirror of' on slave live server suit ?
(thanks again for your helpfull replies, I think these details should be mentionned in the how-to)

 

May be in the future you could try this dns settings with your mirrorred dns server:

 

ahrasis, thanks for your inputs,
I'll try
(but sincerely future setup won't be 'mirror' as it doesn't suit my HA dreams)