Hello all, Although i'm aware that version 1.0.15 is rather old, that's what is used in Lenny, so... Either way, the setup is rather simple, regular dovecot install, with maildirs residing on a "local" ext3 filesystem accessed through FC to a SAN (2Gbps link). The server has 2 cores (with HT), so "almost" 4 cores and 3GB of ram. A couple weeks ago we had a major number of account migrations, from POP to IMAP. We started to notice that in times of peaks, specially after lunch hour, dovecot started to get REALLY slow and closing client connections. A restart to the service was enough to get things working again. Firstly i thought about the max fd number per process, but after checking it turned out it was already rather large, 8192 in our case. I cannot observe any concerning I/O load either. Besides upgrading, are there any suggestions? Regards, Hugo Monteiro. -- fct.unl.pt:~# cat .signature Hugo Monteiro Email : hugo.monteiro at fct.unl.pt Telefone : +351 212948300 Ext.15307 Web : http://hmonteiro.net Divis?o de Inform?tica Faculdade de Ci?ncias e Tecnologia da Universidade Nova de Lisboa Quinta da Torre 2829-516 Caparica Portugal Telefone: +351 212948596 Fax: +351 212948548 www.fct.unl.pt apoio at fct.unl.pt fct.unl.pt:~# _
On 10/08/2010 03:02 PM, Hugo Monteiro wrote:> Hello all, > > Although i'm aware that version 1.0.15 is rather old, that's what is > used in Lenny, so... > > Either way, the setup is rather simple, regular dovecot install, with > maildirs residing on a "local" ext3 filesystem accessed through FC to > a SAN (2Gbps link). The server has 2 cores (with HT), so "almost" 4 > cores and 3GB of ram. > > A couple weeks ago we had a major number of account migrations, from > POP to IMAP. We started to notice that in times of peaks, specially > after lunch hour, dovecot started to get REALLY slow and closing > client connections. A restart to the service was enough to get things > working again. > > Firstly i thought about the max fd number per process, but after > checking it turned out it was already rather large, 8192 in our case. > I cannot observe any concerning I/O load either. > > Besides upgrading, are there any suggestions? > > Regards, > > Hugo Monteiro. >I also forgot to mention that apart from a bug, i though that MAYBE the login_* options could influence in this matter, hence the subject of the message. The values i use are: login_process_per_connection = yes login_processes_count = 10 login_max_processes_count = 40 login_process_size = 64 Thanks again. -- fct.unl.pt:~# cat .signature Hugo Monteiro Email : hugo.monteiro at fct.unl.pt Telefone : +351 212948300 Ext.15307 Web : http://hmonteiro.net Divis?o de Inform?tica Faculdade de Ci?ncias e Tecnologia da Universidade Nova de Lisboa Quinta da Torre 2829-516 Caparica Portugal Telefone: +351 212948596 Fax: +351 212948548 www.fct.unl.pt apoio at fct.unl.pt fct.unl.pt:~# _
Hugo Monteiro wrote:> Although i'm aware that version 1.0.15 is rather old, that's what is > used in Lenny, so... >I expect you already know this, but Debian backports for Lenny does include version 1.2.13 for Dovecot http://packages.debian.org/lenny-backports/i386/dovecot-common/download On that page there are instructions - which I guess you already have - for adding the backport repositories to you software upgrade system. If you were minded to download the files directly, you would need the POP and IMAP programs as well; I'd just use the synaptic system, myself. <snip>> > Besides upgrading, are there any suggestions?Apologies for not being able to offer any 'real' help for your problem, but just I'd mention 1.2.13 on Debian in case it was helpful. regards, Ron
On 08/10/2010 15:02, Hugo Monteiro wrote:> Although i'm aware that version 1.0.15 is rather old, that's what is > used in Lenny, so...1.0.15 is ancient. Please consider upgrading to at least 1.2.x. There is a package for 1.2.13 available in Lenny backports http://packages.debian.org/lenny-backports/dovecot-common replete with binaries for 9 architectures. Bill
On 8.10.2010, at 17.26, Hugo Monteiro wrote:>> A couple weeks ago we had a major number of account migrations, from POP to IMAP. We started to notice that in times of peaks, specially after lunch hour, dovecot started to get REALLY slow and closing client connections. A restart to the service was enough to get things working again.Dunno.>> Firstly i thought about the max fd number per process, but after checking it turned out it was already rather large, 8192 in our case. I cannot observe any concerning I/O load either.If there was a problem with lack of fds, it would log errors.> login_process_per_connection = yes > login_processes_count = 10 > login_max_processes_count = 40 > login_process_size = 64Those are probably too low. Now you only make it possible to use 40 SSL connections at the same time. You should try high performance mode anyway: http://wiki.dovecot.org/LoginProcess