dovecot - Jul 2021 - High Availability Dovecot / Roundcube / PostfixAdmin ?

This is a new setup, running on RHEL 8 with the latest everything.

Has anyone out there set up a high availability pair of Dovecot servers - with
Roundcube and PostfixAdmin - successfully ?

"Callahan's Law: Shared pain is lessened; shared joy, increased ? thus
do we refute entropy" (Spider Robinson)

I do that with two Debian 10 servers - Postfix, PostfixAdmin, Dovecot, MariaDB,
Keepalived.
MariaDB in active/active mode, each node accesses the DB via localhost, Dovecot
with dsync replication, Keepalived for a virtual ip.
The MX record points to each node, DNS A/PTR records for the clients pointing to
the virtual ip.

I separated Roundcube from the mail server and have them running on two separate
VM's as i didn't want to expose the webserver on the mail servers
to the Internet.
There is also keepalived on the two webmail VM's for a virtual ip where the
users connect to.
Both Roundcube instances connect to the DB or SMTP/LDAP server via the virtual
ip there.

Working since almost two years without issues.

On 7/9/21 11:15 AM, White, Daniel E. (GSFC-770.0)[NICS]
wrote:
> This is a new setup, running on RHEL 8 with the latest everything.
>
> Has anyone out there set up a high availability pair of Dovecot servers 
- with Roundcube and PostfixAdmin - successfully ?
>
> "Callahan's Law: Shared pain is lessened; shared joy, increased ? 
thus do we refute entropy" (Spider Robinson)
>
>
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On 09-07-2021 19:15, White, Daniel E. (GSFC-770.0)[NICS]
wrote:
> This is a new setup, running on RHEL 8 with the latest everything.
> 
> Has anyone out there set up a high availability pair of Dovecot
> servers - with Roundcube and PostfixAdmin - successfully ?
Yes. NFS or GlusterFS for shared storage, Keepalived, Percona 
XtraDB+ProxySQL as database backend, Postfix, Dovecot, nginx as reverse 
proxy for Apache w. PHP-FPM. Suggest you start from the bottom up and 
*please* add monitoring for all services, look at Nagios/NRPE w. Percona 
monitoring plugins, more often than not a life saver. If things can go 
pear-shaped they will :)
Cheers,

-- 
Adi Pircalabu