Multiple A Records for IMAP service
Hello All,
I have a quick question.
I have 2 MX servers each with a Dovecot Instances (2.2.6). These 2 Dovecot Instances are replicated by using Dsync... All works well.
The questions is, Can I have 2 A records for my imap.mydomain.tld? The Idea being, if for any reason, one of the Dovecot IMAP instances are unreachable, the client can connect to the other Instance. (this is purely a fail over scenario).
If it matters, The clients are Thunderbird, Android Native (default) Mail client, iOS Mail Client.
-Thanks in advance Vijay
Hi Vijay,
No, this will not work properly. 50% of the time the client will still try to connect to the downed server.
You need something like keepalived or corosync/pacemaker.
Cheers
Alex
On 29/08/14 11:52, Vijay Rajah wrote:
Hello All,
I have a quick question.
I have 2 MX servers each with a Dovecot Instances (2.2.6). These 2 Dovecot Instances are replicated by using Dsync... All works well.
The questions is, Can I have 2 A records for my imap.mydomain.tld? The Idea being, if for any reason, one of the Dovecot IMAP instances are unreachable, the client can connect to the other Instance. (this is purely a fail over scenario).
If it matters, The clients are Thunderbird, Android Native (default) Mail client, iOS Mail Client.
-Thanks in advance Vijay
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On 29.8.2014 13:00, Alex Crow wrote:
Hi Vijay,
No, this will not work properly. 50% of the time the client will still try to connect to the downed server.
You need something like keepalived or corosync/pacemaker.
Cheers
Alex
AFAIK some clients - with Thunderbird among them - will try the other IP address before reporting an error to the user.
I agree with Alex and Jiri.
Here I have the same scenario, DNS round-robin and 2 dovecot instances. It works well, but depends on the client implementation.
I think keepalived or corosync/pacemaker is a more elegant solution too. I can help you implement.
On 08/29/2014 08:34 AM, Jiri Bourek wrote:
On 29.8.2014 13:00, Alex Crow wrote:
Hi Vijay,
No, this will not work properly. 50% of the time the client will still try to connect to the downed server.
You need something like keepalived or corosync/pacemaker.
Cheers
Alex
AFAIK some clients - with Thunderbird among them - will try the other IP address before reporting an error to the user.
On 2014-08-29 12:52, Vijay Rajah wrote:
The questions is, Can I have 2 A records for my imap.mydomain.tld? The Idea being, if for any reason, one of the Dovecot IMAP instances are unreachable, the client can connect to the other Instance. (this is purely a fail over scenario).
I can confirm that these clients work very well:
Mail client, iOS Mail Client.
Those clients will take any available server. Switching from one server to the other will take place unnoticed to the client user.
Regards, Michael
participants (5)
-
Alex Crow
-
Eduardo Ramos
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Jiri Bourek
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Michael Grimm
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Vijay Rajah