On Fri, 3 Jul 2015 14:29:55 +0900 Christian Balzer wrote:
On Fri, 03 Jul 2015 07:05:43 +0200 Urban Loesch wrote:
Hi,
Am 03.07.2015 um 05:14 schrieb Christian Balzer:
- Here is where the fun starts. Each IMAP session that gets proxied to the real mailbox server needs a port for the outgoing connection. So to support 2 million sessions we need 40 IP addresses here. Ouch. And from a brief test having multiple IP addresses per server won't help either (Dovecot unsurprisingly picks the main IP when establishing a proxy session to the real mailbox), at least not with just one default GW.
To follow up on myself, with multiple IPs and appropriate(*) iproute rules this works as well.
(*) for each IP in "interfaces" add something like this:
up ip route add 192.168.1.0/24 dev eth0 src 192.168.1.109 table T2
up ip route add default via 192.168.1.1 table T2
up ip rule add from 192.168.1.109 table T2And the tables in "/etc/iproute/rt_tables".
Christian
If I remeber correctly there is a config option in dovecot 2.x where you can set the ip addresses which dovecot should use for outgoing proxy connections. Sorry, but I can't remeber the option.
Looking at the documentation on the Wiki I was going to say "That won't help", as it says address. http://wiki2.dovecot.org/PasswordDatabase/ExtraFields/Proxy
But since that page is rather terse, I looked up the changelog and found that it indeed was added for use cases like mine: http://www.dovecot.org/list/dovecot-cvs/2014-June/024574.html
Unfortunately the latest dovecot version in Debian is 2.2.13...
Additionally this still leaves the actual mailbox servers, which in my case will need to be able to handle more than 50k sessions as well.
Thanks for the info,
Christian
--
Christian Balzer Network/Systems Engineer
chibi@gol.com Global OnLine Japan/Fusion Communications
http://www.gol.com/