reason to switch to 1.1

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reason to switch to 1.1

Cor Bosman
We've been running 1.1 on about half of our servers for about a week now.
Ive mailed before that I was pleasantly surprised by its better use of
resources. Here's a graph showing that fact. Server load in the last 10
days.

http://uwimages.smugmug.com/photos/286355874_9FNp2-L.png

Cor
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Re: reason to switch to 1.1

Anders-19
Cor Bosman wrote:

> We've been running 1.1 on about half of our servers for about a week now.
> Ive mailed before that I was pleasantly surprised by its better use of
> resources. Here's a graph showing that fact. Server load in the last 10
> days.

It may be good to list your hardware, user count, mailbox backend, and
file system information, as I suppose that this kind of improvement is not
universal.


Anders.


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Re: reason to switch to 1.1

Cor Bosman
> > We've been running 1.1 on about half of our servers for about a week now.
> > Ive mailed before that I was pleasantly surprised by its better use of
> > resources. Here's a graph showing that fact. Server load in the last 10
> > days.
>
> It may be good to list your hardware, user count, mailbox backend, and
> file system information, as I suppose that this kind of improvement is not
> universal.

This specific server is a dual core 2.8ghz xeon with hyperthreading
running on FreeBSD 6.2-STABLE. We have over 1 million mailboxes, with about
75,000 daily active users. At peak maybe 20,000 concurrent, in a mix of
webmail and direct imap.  (no POP, thats handled by different software).

The backend is a NetAPP 6070 with about 170 harddisks. All mail and
control files are on this netapp, but all indexes are on local disks, and
we try and make sure customers end up on the same imap server every time.
As soon as all servers are 1.1 I'll start experimenting with NFS indexes.

Cor
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Re: reason to switch to 1.1

Marc Perkel
In reply to this post by Cor Bosman
Very persuasive. So what is the conversion process like tp go to 1.1?

Cor Bosman wrote:

> We've been running 1.1 on about half of our servers for about a week now.
> Ive mailed before that I was pleasantly surprised by its better use of
> resources. Here's a graph showing that fact. Server load in the last 10
> days.
>
> http://uwimages.smugmug.com/photos/286355874_9FNp2-L.png
>
> Cor
>
>  
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Re: reason to switch to 1.1

Chris Laif
In reply to this post by Cor Bosman
On Mon, Apr 28, 2008 at 12:42 PM, Cor Bosman <[hidden email]> wrote:

>  > It may be good to list your hardware, user count, mailbox backend, and
>  > file system information, as I suppose that this kind of improvement is not
>  > universal.
>
>  This specific server is a dual core 2.8ghz xeon with hyperthreading
>  running on FreeBSD 6.2-STABLE. We have over 1 million mailboxes, with about
>  75,000 daily active users. At peak maybe 20,000 concurrent, in a mix of
>  webmail and direct imap.  (no POP, thats handled by different software).
>
>  The backend is a NetAPP 6070 with about 170 harddisks. All mail and
>  control files are on this netapp, but all indexes are on local disks, and
>  we try and make sure customers end up on the same imap server every time.
>  As soon as all servers are 1.1 I'll start experimenting with NFS indexes.
>

Just in case I understand you wrong: You're serving 20k concurrent
users with 1 (one) server?

What mailbox backend are you using? maildir?

Chris
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Re: reason to switch to 1.1

Cor Bosman
> >  This specific server is a dual core 2.8ghz xeon with hyperthreading
> >  running on FreeBSD 6.2-STABLE. We have over 1 million mailboxes, with about
> >  75,000 daily active users. At peak maybe 20,000 concurrent, in a mix of
> >  webmail and direct imap.  (no POP, thats handled by different software).
> >
> >  The backend is a NetAPP 6070 with about 170 harddisks. All mail and
> >  control files are on this netapp, but all indexes are on local disks, and
> >  we try and make sure customers end up on the same imap server every time.
> >  As soon as all servers are 1.1 I'll start experimenting with NFS indexes.
> >
>
> Just in case I understand you wrong: You're serving 20k concurrent
> users with 1 (one) server?
>
> What mailbox backend are you using? maildir?

Actually..it's 2 NetApp 6070s. But those are not just simple servers.
They are very expensive, dedicated NFS boxes each taking up a full rack
doing multiple terrabytes each, connected with multiple gbit links.

It's 99.99% maildir, with a very small hidden mbox legacy namespace.

Cor
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Re: reason to switch to 1.1

Cor Bosman
In reply to this post by Chris Laif
> Just in case I understand you wrong: You're serving 20k concurrent
> users with 1 (one) server?

Wait, I think I misunderstood you. We do not have just 1 imap server.
We have 30 imap servers (a little overdimensioned at this time).
I was just showing the graph of one of them. The others look similar.

Cor
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Re: reason to switch to 1.1

Geert Hendrickx
In reply to this post by Cor Bosman
On Tue, Apr 29, 2008 at 09:42:10AM +0200, Cor Bosman wrote:
> Actually..it's 2 NetApp 6070s. But those are not just simple servers.
> They are very expensive, dedicated NFS boxes each taking up a full rack
> doing multiple terrabytes each, connected with multiple gbit links.
>
> It's 99.99% maildir, with a very small hidden mbox legacy namespace.


How large are the (individual) mailboxes you're hosting there?

        Geert


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Re: reason to switch to 1.1

Chris Laif
In reply to this post by Cor Bosman
On Tue, Apr 29, 2008 at 10:31 AM, Cor Bosman <[hidden email]> wrote:
> > Just in case I understand you wrong: You're serving 20k concurrent
>  > users with 1 (one) server?
>
>  Wait, I think I misunderstood you. We do not have just 1 imap server.
>  We have 30 imap servers (a little overdimensioned at this time).
>  I was just showing the graph of one of them. The others look similar.
>

Thanks for the info.

I conclude that it is no problem to serve about 1000 concurrent users
per server (with dovecot 1.1 probably even lots more!).

Unfortunately I cannot compare this with our setup as we do not have
dedicated NFS-boxes (Netapp). Our servers have to do local hard disk
IO as well. I think this probably decreases performance (?).

Chris
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Re: reason to switch to 1.1

Cor Bosman
In reply to this post by Geert Hendrickx
> How large are the (individual) mailboxes you're hosting there?

Most of them are max 500MB, but average use is much less. It's a little
difficult to calculate because almost all POP users empty their mailbox.
We did some reports a few months ago where it showed that average mailbox
size for POP users is less than 5MB, while average mailbox usage for
IMAP was over 50MB.  

Cor
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Re: reason to switch to 1.1

Geert Hendrickx
On Tue, Apr 29, 2008 at 11:49:43AM +0200, Cor Bosman wrote:
> > How large are the (individual) mailboxes you're hosting there?
>
> Most of them are max 500MB, but average use is much less. It's a little
> difficult to calculate because almost all POP users empty their mailbox.
> We did some reports a few months ago where it showed that average mailbox
> size for POP users is less than 5MB, while average mailbox usage for IMAP
> was over 50MB.  


Ok, so you're probably not facing any filesystem bottlenecks w.r.t. number
of files in a Maildir folder?

        Geert