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. >> > Yeah, but 50 would be a tad too conservative for our purposes here. > I'll keep an eye on it and see how it goes, first checkpoint would be at > 1k hibernated sessions. ^_^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.
On Thu, 6 Apr 2017 13:10:03 +0300 Timo Sirainen wrote:> 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. > >> > > Yeah, but 50 would be a tad too conservative for our purposes here. > > I'll keep an eye on it and see how it goes, first checkpoint would be at > > 1k hibernated sessions. ^_^ > > 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. >I assume the config processes are in the same category, they are happy with 16k clients and using 169MB each, without any issues. ^.^ Christian -- Christian Balzer Network/Systems Engineer chibi at gol.com Global OnLine Japan/Rakuten Communications http://www.gol.com/
On Thu, Apr 6, 2017 at 3:10 AM, Timo Sirainen <tss at iki.fi> wrote:> 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. > >> > > Yeah, but 50 would be a tad too conservative for our purposes here. > > I'll keep an eye on it and see how it goes, first checkpoint would be at > > 1k hibernated sessions. ^_^ > > 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 imap-login/pop3-login? Would the same apply for imap-login when it's being used in proxy mode? I'm moving us to a director setup (cf. my other email about director rings getting wedged from a couple days ago) and, again, for the sake of starting conservatively, I've got imap-login set to a client limit of 20, since I figure that proxying is a lot more work than just doing IMAP logins. I'm doing auth to mysql at both stages (at the proxy level and at the backend level). On a sample director box, I've got 10000 imap connections, varying from 50mbit/sec to the backends up to 200mbit/sec. About a third of the connections are TLS, if that makes a diff. That's pretty normal from what I've seen. The director servers are usually 90-95% idle. Should I be able to handle a much higher client_limit for imap-login and pop3-login than 20?
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 > imap-login/pop3-login?You should have the same number of imap-login processes as the number of CPU cores, so they can use all the available CPU without doing unnecessary context switches. The client_limit is then large enough to handle all the concurrent connections you need, but not so large that it would bring down the whole system if it actually happens.> Would the same apply for imap-login when it's being used in proxy mode? I'm > moving us to a director setup (cf. my other email about director rings > getting wedged from a couple days ago) and, again, for the sake of starting > conservatively, I've got imap-login set to a client limit of 20, since I > figure that proxying is a lot more work than just doing IMAP logins. I'm > doing auth to mysql at both stages (at the proxy level and at the backend > level).Proxying isn't doing any disk IO or any other blocking operations. There's no benefit to having more processes. The only theoretical advantage would be if some client could trigger a lot of CPU work and cause delays to handling other clients, but I don't think that's possible (unless somehow via OpenSSL but I'd guess that would be a bug in it then).> Should I be able to handle a much higher client_limit for imap-login and > pop3-login than 20?Yeah.