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Topic: High availability

dear ZhangHuanBin and all the others,
i am working on my project for the final year of diploma in computer engineering, as a part of the project i have also taken up load balancing of the mail server and was looking forward to make use of iRedMail for the same... i have been constantly trying.. As far as the load balancing is concerned, im sure it would work but the issue is with the high availability..
This is exactly what i did..
a) setup iredmail 0.8.4 on both the servers with mysql 5.5 as the backend and its working.
b) Add 2-3 test users on one server and tried sending mails to the users on the same server. IT worked.
c) i dumped sql data from 1st server to 2nd and the from 2nd to first so that both have same data!
d) setup unison for 2 way synchronization of /var/vmail//
according to me this should have worked, at this instance atleast i should have been able to login with the same ids from both the servers and view mails which earlier existed on server1..
but instead the system turned totally unstable.
On one of the servers roundcube displayed message could not connect to the database server and the second server displayed could not connect to the storage server... any idea about what might have gone wrong?
is there anything else i need to look into? please help asap

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Re: High availability

amol_shandilya wrote:

dear ZhangHuanBin and all the others,
i am working on my project for the final year of diploma in computer engineering, as a part of the project i have also taken up load balancing of the mail server and was looking forward to make use of iRedMail for the same... i have been constantly trying.. As far as the load balancing is concerned, im sure it would work but the issue is with the high availability..
This is exactly what i did..
a) setup iredmail 0.8.4 on both the servers with mysql 5.5 as the backend and its working.
b) Add 2-3 test users on one server and tried sending mails to the users on the same server. IT worked.
c) i dumped sql data from 1st server to 2nd and the from 2nd to first so that both have same data!
d) setup unison for 2 way synchronization of /var/vmail//
according to me this should have worked, at this instance atleast i should have been able to login with the same ids from both the servers and view mails which earlier existed on server1..
but instead the system turned totally unstable.
On one of the servers roundcube displayed message could not connect to the database server and the second server displayed could not connect to the storage server... any idea about what might have gone wrong?
is there anything else i need to look into? please help asap

I think this leads to httpd session errors in roundcube... how do you do the load-balance? round-robin?
There should be a session-aware load-balancing tool, I've read something a few months ago, but can't find it right now...

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Re: High availability

First of all, please always creating new forum topic for your own questions instead of hijacking others'.

amol_shandilya wrote:

c) i dumped sql data from 1st server to 2nd and the from 2nd to first so that both have same data!

MySQL replication is better. But manually dumping is ok for testing.

amol_shandilya wrote:

d) setup unison for 2 way synchronization of /var/vmail/

May i know how you sync it on two servers?
A shared storage is better if possible. For example, NAS storage, NFS sharing, DRBD, etc.

amol_shandilya wrote:

On one of the servers roundcube displayed message could not connect to the database server and the second server displayed could not connect to the storage server

*) Roundcube cannot connect to the db server, you should check whether MySQL server is running. And the SQL username/password configured in Roundcube config file config/db.inc.php.

*) Roundcube cannot connect to storage server, please check managesieve service in Dovecot config file, and Roundcube plugin: plugins/managesieve/config.inc.php. e.g. listen port.