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<p>presumably, you would have the same database parameters on
different hosts, so only adding an additional "host=" parameter
should suffice. i would only add the additional parameters that
are unique or different, and that should work.</p>
<p>connect = "host=<dbserver1> host=<dbserver2>
dbname=<dbname> user=<dbuser> password=<dbpass>"</p>
<p>sorry to hear your going to test this in Prod. :(<br>
</p>
<div class="moz-cite-prefix">On 8/30/22 6:10 PM, Jack Snodgrass
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:8cde94a1-e4cd-8945-bf37-7c6660d59369@mylinuxguy.net">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<p><br>
I prefer to use a 2 db approach where I specify 2 different
Database servers as opposed to HAproxy. <br>
</p>
<p><br>
</p>
<p>I see on: <a class="moz-txt-link-freetext"
href="http://url7179.mylinuxguy.net/ls/click?upn=qw3mUGlvypxOIEjnzoVznczKsajdyZbXY6uGLmuK5J6I8VjNhJjPybLy8wVGpS-2Bj0XbXGjmYqz5kJ-2FqxxfqOlD5-2FM5yJRqhCXliHjUJoMpE-3Di253_5qhfSnrBXIaXI7rIewPfzICYfubUoDIKRg6-2F2vb7-2BoHPlQu-2FfbGVKyxQX-2F2MK4nxWkxmetPK3bISYq-2B3vMMCqg0OvFazMQP6kieDgzySn3CxXosvGvmxmnaV8gXFIELIwC0p6Z0DD1bjbNKHnx962D5GbY3WllOadyCtSiaOHgFtg3Bl1e1T2WPo2YFLuLkM-2BTim9nrs0zpBRq5fOgwlhw-3D-3D"
moz-do-not-send="true">https://doc.dovecot.org/configuration_manual/authentication/sql</a>
where it says: <br>
</p>
<p><b>You can add multiple host parameters to the SQL connect
string. Dovecot will do round robin load balancing between
them. If one of them goes down, the others will handle the
traffic.</b><br>
<br>
it would be really nice if that was expanded opon in the
docs.... I am not sure WHO to ask that that be clarified. <br>
</p>
<p>I currently have: <br>
</p>
<p>connect = "host=<dbserver> dbname=<dbname>
user=<dbuser> password=<dbpass>"</p>
<p>... would I use: <br>
</p>
<p>connect = "host=<dbserver> dbname=<dbname>
user=<dbuser> password=<dbpass>
host=<dbserver2> dbname=<dbname2>
user=<dbuser2> password=<dbpass2>" <br>
</p>
<p>and the system would just see host/host, dbname/dbname
user/user password/password and automatically map the correct
dbname/user/password to the correct host or it is assumed that
the 2nd host is the only thing that changes and the
dbname/user/password are the same? or do I use: <br>
</p>
<p>connect = "host=<dbserver> dbname=<dbname>
user=<dbuser> password=<dbpass>
host2=<dbserver> dbname2=<dbname>
user2=<dbuser> password2=<dbpass>" <br>
</p>
<p>to specify the host and host2 info? <br>
</p>
<p><br>
</p>
<p>"You can add multiple host parameters to the SQL connect
string." is a bit lacking in info when you think about the
possibility of having a different user/pass or dbname for the
2nd host instance. <br>
<br>
I am going to play around with this on my production box... but
having a bit more info in the docs would be preferred. <br>
</p>
<p><br>
</p>
<p>- jack <br>
</p>
<p><br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 8/30/22 07:57 AM, Brendan Kearney
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:ed259a7f-4e6a-a198-d8c0-6a813e34503b@gmail.com">
<meta http-equiv="Content-Type" content="text/html;
charset=UTF-8">
<p>per <a class="moz-txt-link-freetext"
href="http://url7179.mylinuxguy.net/ls/click?upn=qw3mUGlvypxOIEjnzoVznczKsajdyZbXY6uGLmuK5J6I8VjNhJjPybLy8wVGpS-2Bj0XbXGjmYqz5kJ-2FqxxfqOlD5-2FM5yJRqhCXliHjUJoMpE-3DKmhV_5qhfSnrBXIaXI7rIewPfzICYfubUoDIKRg6-2F2vb7-2BoHPlQu-2FfbGVKyxQX-2F2MK4nxPqq-2BxqulnD7vrxF869qXLsnUwNVtKImZgjhrrc8-2BgQcto-2FlJJcOMywfxCTc2-2BxoPX7HPBMfNvES9Vhh3H7JdildFpXiixy8xTdPoXwp7cMdcphsBsaaKDR5kjS91YmrjyCMVCsJQUtzWCgnHHGTxxg-3D-3D"
moz-do-not-send="true">https://doc.dovecot.org/configuration_manual/authentication/sql/</a>,
you can add more than one "host=" parameter in the "connect"
directive, and leave dovecot to do round-robin load
balancing. there will probably be a delay in processing while
a failed database connection attempt times out.</p>
<p>or you can use a load balanced database footprint, using
something like haproxy. its not as simple as putting multiple
databases behind haproxy and calling it done. i use mariadb,
which via galera, can do multi-primary HA, where all 3 primary
instances can take write or read events. you need to
configure each mariadb instance with galara replication and
then setup haproxy to properly attach to the databases and
perform a service check.</p>
<p>postgresql or other databases may require different
mechanisms to achieve fault tolerant HA.<br>
</p>
<div class="moz-cite-prefix">On 8/30/22 4:18 AM, Sami Ketola
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:701B07A6-6F15-412B-9A6A-A8B60ED9B581@ketola.io">
<meta http-equiv="Content-Type" content="text/html;
charset=UTF-8">
<br class="">
<div><br class="">
<blockquote type="cite" class="">
<div class="">On 30. Aug 2022, at 5.13, Jack Snodgrass
<<a href="mailto:jack@mylinuxguy.net"
class="moz-txt-link-freetext" moz-do-not-send="true">jack@mylinuxguy.net</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<meta http-equiv="content-type" content="text/html;
charset=UTF-8" class="">
<div class="">
<p class=""><br class="">
</p>
<p class="">I am using this file: <br class="">
</p>
<p class="">dovecot-sql.conf.ext</p>
<p class="">and in there I have a <br class="">
</p>
<p class="">connect = "host=<dbserver>
dbname=<dbname> user=<dbuser>
password=<dbpass>"</p>
<p class=""><br class="">
</p>
<p class="">My <dbserver> was down and I lost
mail access for a few days before I realized that
there was an issue. How can I specify a backup
server so that if my primary sql server goes down, a
backup sql server will be queried?<br class="">
</p>
</div>
</div>
</blockquote>
<br class="">
</div>
<div>Use haproxy.</div>
<div><br class="">
</div>
<div>Sami</div>
<div><br class="">
</div>
<br class="">
</blockquote>
</blockquote>
<div class="moz-signature"
signature-switch-id="f495ce62-5c58-4122-b492-559481da1cf6">-- <br>
jack - Southlake Texas - <a
href="http://url7179.mylinuxguy.net/ls/click?upn=qw3mUGlvypxOIEjnzoVznaPhh1QZR9rdwcvCQ0qavLA-3DUiiX_5qhfSnrBXIaXI7rIewPfzICYfubUoDIKRg6-2F2vb7-2BoHPlQu-2FfbGVKyxQX-2F2MK4nxxMgskp-2B7lkCgnLNSC-2BkHg-2BIZivmGnYzgw6K5Dw5Rkff8q-2FIoZHz2vWzOlfXpUNTznP1U4-2FAL3aStk0Rg0h6GpRg4at3NFRAD3w1S5-2B-2BXy4ne0c-2FXuQOKNksIOpgzzBd5FuBUlJpA0KfWocho2TNHnA-3D-3D"
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