similar to: Anyone using object storage ceph?

I just read this blog: https://mrotaru.wordpress.com/2013/10/10/scaling-to-12-million-concurrent-connections-how-migratorydata-did-it/ <https://mrotaru.wordpress.com/2013/10/10/scaling-to-12-million-concurrent-connections-how-migratorydata-did-it/> about scaling to 12 Million Concurrent Connections on a single server and it got me thinking. Would it be possible to scale Dovecot IMAP server

> 1. 256GB of real RAM, swap is for chums. Are you sure that 100,000 IMAP sessions wouldn?t work well with SWAP, especially with fast SSD storage (which is a lot cheaper than RAM)? Seems that these IMAP processes are long lived processes (idling most of the time) that don?t need that much of the contents of real memory available for much of the life of the process. I use a database proxy in

> 1500 IMAP sessions will eat up about 3GB alone. Are you saying that Dovecot needs 2MB of physical memory per IMAP session? If I want to support a max 100,000 IMAP sessions per server, I should configure the server to have at least 200GBs of SWAP? > On Feb 10, 2017, at 3:58 AM, Christian Balzer <chibi at gol.com> wrote: > > On Fri, 10 Feb 2017 01:13:20 +0530 Rajesh M wrote:

Hi, I've very old Dovecot version so I'm trying to migrate new disk and current version of dovecot. But POP3 accounts have "version 1" .INBOX/dovecot-uidlist files so clients download the messages again. How can achieve not to download to mailbox after copy to new disk? Is there any script or something to migrate index v1 to v3? thanks for your suggestions.

Thanks for the info. I do have one further question for you. On your servers that are currently handling 50k IMAP sessions, how many users does that correspond to? Since many users will have multiple IMAP sessions on multiple devices, I?d like to hear about some real-world numbers that could be used for budgeting a new project like mine. Also, do you use Dovecot IMAP proxies in front of your

thanks for your help happy to say that the performance dramatically improved after i use the high performance settings from here http://wiki.dovecot.org/LoginProcess grep Login: /var/log/mail.log.1 |wc -l with the mail.log being of a typical, busy day. 412992 i also picked up the imap and pop3 connections during peak hours [root at ns1 domains]# doveadm who | awk

Hello, On Thu, 6 Apr 2017 09:24:23 +0300 Aki Tuomi wrote: > On 06.04.2017 07:02, Christian Balzer wrote: > > > > Hello, > > > > this is on Debian Jessie box, dovecot 2.2.27 from backports, > > imap-hibernate obviously enabled. > > > > I've been seeing a few of these since starting this cluster (see previous > > mail), they all follow the

Hello, Dovecot 2.2.27 (Debian Jessie backports). When issuing a "doveadm kick" for a specific user I was greeted by: --- "warning: other connections would also be kicked from following users:" --- and a list of 22odd thousand users. As it turns out, kick wants to smack the hibernation proces(ses) that have hibernated sessions for this user, obviously the wrong approach here.

christian the servers i currently own are dell servers. The servers i plan to buy are Dell R530, 2U rack servers with 8 x 3.5 inch drives, with 64 gb ram each, Hardware raid. I am thinking of 2 X 300 gb ssds raid1 and 6 x 2 tb drives in raid10 for data. I do not have any experience in setting up drdb (that would be my next step) ... primarily using standalone servers with hardware level

Daniel, thanks so much for the detailed pointers. So it turns out to be both the evil that is systemd and an overzealous upgrade script. Apollon, should I raise a Debian bug for this? As for reasons, how do 50k proxy session on the proxy servers and 25k imap processes on the mailbox servers sound? Even on a server with just 6k users and 7k imap processes that causes a massive load spike and a

On 6 Apr 2017, at 21.14, Mark Moseley <moseleymark at gmail.com> wrote: > >> >> imap-hibernate processes are similar to imap-login processes in that they >> should be able to handle thousands or even tens of thousands of connections >> per process. >> > > TL;DR: In a director/proxy setup, what's a good client_limit for >

Hello, We've got a pretty substantial dovecot installation (versions 2.1.7 and 2.2.13 on the backends, but tested with 2.2.24 as well) and this is the relevant config snippet from 10-master.conf: --- default_process_limit = 1024 default_client_limit = 16384 [...] service imap { # Most of the memory goes to mmap()ing files. You may need to increase this # limit if you have huge

On 6 Apr 2017, at 9.56, Christian Balzer <chibi at gol.com> wrote: > >> For no particular reason besides wanting to start conservatively, we've got >> client_limit set to 50 on the hibernate procs (with 1100 total hibernated >> connections on the box I'm looking at). At only a little over a meg each, >> I'm fine with those extra processes. >>

Hello, as the tin says. I have several servers running 2.2.27 (Debian stretch) and am adding new ones with 2.3.4.1 (Debian buster). The configs were upgraded where needed but neither 10-mail.conf nor 15-mailboxes.conf were changed. 15-mailboxes is all commented out (I guess the default is auto-create, which isn't documented anywhere I could find) and the only non-comments in 10-mail.conf are

Hello, this is on Debian Jessie box, dovecot 2.2.27 from backports, imap-hibernate obviously enabled. I've been seeing a few of these since starting this cluster (see previous mail), they all follow the same pattern, a user who accesses their mailbox with both POP3 and IMAP deletes mails with POP3 and the IMAP (imap-hibernate really) is getting confused and upset about this: --- Apr 6

Hello, Both the examples on the Push Notification wiki page and the XAPS plugin docs seem to suggest or state that LMTP/LDA is required. However IMAP IDLE notifications work without either of these (please no religious discussion of why Dovecot LMTP is the best thing since sliced bread and that everybody should use it). The LUA part of the push notification docs however states that events other

Am 30.08.19 um 10:00 schrieb Christian Balzer via dovecot: > When upgrading on Debian Stretch with the security fix packages all > dovecot processes get killed and then restarted despite having > "shutdown_clients = no" set. This is systemd doing its "magic" (kill all control group processes), see https://dovecot.org/pipermail/dovecot/2016-June/104546.html for a

----- Original Message ----- From: Christian Balzer [mailto:chibi at gol.com] To: dovecot at dovecot.org Cc: 24x7server at 24x7server.net Sent: Fri, 10 Feb 2017 17:58:58 +0900 Subject: On Fri, 10 Feb 2017 01:13:20 +0530 Rajesh M wrote: > hello > > could somebody with experience let me know the dovecot config file settings to handle around 1500 simultaneous connections over pop3 and

"Rajesh M" <24x7server at 24x7server.net> writes: > during peak times here are the results for connections > > [root at ns1 domains]# doveadm who |grep imap |wc -l > username # proto (pids) (ips) > 631 > [root at ns1 domains]# doveadm who |grep pop3 |wc -l > username # proto (pids)

hello could somebody with experience let me know the dovecot config file settings to handle around 1500 simultaneous connections over pop3 and 1500 connection over imap simultaneously. my server server configuration hex core processor, 16 gb ram 1 X 600 gb 15 k rpm for main drive and 2 X 2000 gb hdd for data (No raid) thanks rajesh my current config file settings as such # 2.2.7: