dovecot - Mar 2012 - imaptest: performance testing

Dear Folks,

Using head of imaptest with dovecot 2.1, I am attempting to put a
heavy load on the server, with insufficient success.

I made 15000 user accounts, put them in to a file, one per line.  Then
I ran imaptest with

./imaptest userfile=../../imap-test-userlist-15001.txt clients=15001
pass=SECRETPASSWORD

But CPU load is only reaching 20.

I put an mbox containing 67 messages into ~/mail/dovecot-crlf

So what is the best way to put a really heavy load on an imap server?
The documentation describes testing correctness of the server without
really emphasising performance.

I would like to do something like dnsperf, which adds a linearly
increasing load until the server is unable to cope.

This machine has 24G RAM and 8 cores.  I'll be grateful for any
constructive suggestions.
-- 
Nick Urbanik             http://nicku.org           nicku at nicku.org
GPG: 7FFA CDC7 5A77 0558 DC7A 790A 16DF EC5B BB9D 2C24 ID: BB9D2C24

On 16.3.2012, at 12.08, Nick Urbanik wrote:
> Using head of imaptest with dovecot 2.1, I am attempting to put a
> heavy load on the server, with insufficient success.
> 
> I made 15000 user accounts, put them in to a file, one per line.  Then
> I ran imaptest with
> 
> ./imaptest userfile=../../imap-test-userlist-15001.txt clients=15001
> pass=SECRETPASSWORD
A single imaptest process can't handle that many simultaneous clients.
You'd need to run multiple imaptests in parallel.
> So what is the best way to put a really heavy load on an imap server?
> The documentation describes testing correctness of the server without
> really emphasising performance.
Yes, imaptest is mainly meant to test server correctness (i.e. for me to test
that Dovecot is bugfree). It spends a lot of time checking and tracking things
that is irrelevant when you simply want to load the server. You could add
no_tracking parameter to get rid of some of it.

On 2012-03-16 9:17 AM, Timo Sirainen <tss at iki.fi>
wrote:
> imaptest is mainly meant to test server correctness (i.e. for me to
> test that Dovecot is bugfree). It spends a lot of time checking and
> tracking things that is irrelevant when you simply want to load the
> server. You could add no_tracking parameter to get rid of some of it.
Maybe imaptest could be duped+modified somehow to produce a new 
imap_load_test utility...?

-- 

Best regards,

Charles