Re: Dovecot Director upgrade from 2.2 to 2.3

[Alessio Cecchi via dovecot]

Il 22/07/19 18:49, Timo Sirainen ha scritto:

On 22 Jul 2019, at 17.45, Alessio Cecchi > wrote:


one server of the ring is now running Dovecot 2.3.7 and works fine 
with the others Dovecot 2.2 since 3 days.


I notice only that the load avarage of this CentOS 7 server is higher 
compared with CentOS 6 and Dovecot 2.2, but I don't know if is 
related to the new operating system or Dovecot (hardware is the same).


How much higher? Can you check the individual dovecot processes' CPU 
usage? I guess mainly director, imap-login and pop3-login. The 
director code should be pretty much the same though.


The SSL code in login processes changed in v2.3, so I wonder if the 
new code has some performance issues.


Just for info,

I have upgraded all directors ring to Dovecot 2.3 but maintaining CentOS 
6 and the load average is the same, so the increase of load during the 
first upgrade was caused by CentOS 7, not by Dovecot 2.3.


Ciao

--
Alessio Cecchi
Postmaster @ http://www.qboxmail.it
https://www.linkedin.com/in/alessice

Re: Dovecot Director upgrade from 2.2 to 2.3

[Timo Sirainen via dovecot]

On 31 Jul 2019, at 15.41, Alessio Cecchi via dovecot  
wrote:
> 
> Hi Timo,
> 
> here you can see two images with the load average and CPU usage with Dovecot 
> 2.2 (Centos 6) and 2.3 (Centos 7) on the same hardware and same configuration:
> 
> https://imgur.com/a/1hsItlc 
> Load average increment is relevant but CPU usage is similar.
> 

Load average changes can be rather difficult to debug if it's not because of 
any CPU usages or disk IO, and in your graphs those hadn't really changed. One 
more possibility could be to look at context switches, but do you have those 
from before the upgrade? (sar database?) Also since you changed CentOS 6 -> 7 
it could be possible that it has nothing to do with Dovecot at all.

Re: Dovecot Director upgrade from 2.2 to 2.3

[Alessio Cecchi via dovecot]

Hi Timo,

here you can see two images with the load average and CPU usage with 
Dovecot 2.2 (Centos 6) and 2.3 (Centos 7) on the same hardware and same 
configuration:


https://imgur.com/a/1hsItlc

Load average increment is relevant but CPU usage is similar.

Il 22/07/19 18:49, Timo Sirainen ha scritto:

On 22 Jul 2019, at 17.45, Alessio Cecchi > wrote:


one server of the ring is now running Dovecot 2.3.7 and works fine 
with the others Dovecot 2.2 since 3 days.


I notice only that the load avarage of this CentOS 7 server is higher 
compared with CentOS 6 and Dovecot 2.2, but I don't know if is 
related to the new operating system or Dovecot (hardware is the same).


How much higher? Can you check the individual dovecot processes' CPU 
usage? I guess mainly director, imap-login and pop3-login. The 
director code should be pretty much the same though.


The SSL code in login processes changed in v2.3, so I wonder if the 
new code has some performance issues.



--
Alessio Cecchi
Postmaster @ http://www.qboxmail.it
https://www.linkedin.com/in/alessice

Re: Dovecot Director upgrade from 2.2 to 2.3

[Timo Sirainen via dovecot]

On 22 Jul 2019, at 17.45, Alessio Cecchi  wrote:
> 
> one server of the ring is now running Dovecot 2.3.7 and works fine with the 
> others Dovecot 2.2 since 3 days.
> I notice only that the load avarage of this CentOS 7 server is higher 
> compared with CentOS 6 and Dovecot 2.2, but I don't know if is related to the 
> new operating system or Dovecot (hardware is the same).
> 
How much higher? Can you check the individual dovecot processes' CPU usage? I 
guess mainly director, imap-login and pop3-login. The director code should be 
pretty much the same though.

The SSL code in login processes changed in v2.3, so I wonder if the new code 
has some performance issues.

Re: Dovecot Director upgrade from 2.2 to 2.3

[Alessio Cecchi via dovecot]

Il 18/07/19 21:42, Timo Sirainen ha scritto:
On 18 Jul 2019, at 11.44, Alessio Cecchi via dovecot 
mailto:dovecot@dovecot.org>> wrote:


Hi,

I have a setup with 3 Dovecot Director v2.2.36 and 
director_consistent_hashing = yes ;-)


Now I would like to upgrade to 2.3.7, first only Director and after 
also Backend.


Can works fine a ring of director with mixed 2.2 and 2.3 version?

Mi idea is to setup a new Director server with 2.3, stop one server 
with 2.2 and insert the new 2.3 in the current ring to check if works 
fine.


If all works fine I will replace all Director 2.2 with 2.3 version.



There's no known reason why it wouldn't work. But be prepared in case 
there is an unknown reason.


Hi,

one server of the ring is now running Dovecot 2.3.7 and works fine with 
the others Dovecot 2.2 since 3 days.


I notice only that the load avarage of this CentOS 7 server is higher 
compared with CentOS 6 and Dovecot 2.2, but I don't know if is related 
to the new operating system or Dovecot (hardware is the same).


If I do not encounter problems in the next days I will also update the 
other Directors.


Thanks

--
Alessio Cecchi
Postmaster @ http://www.qboxmail.it
https://www.linkedin.com/in/alessice

Re: Dovecot Director upgrade from 2.2 to 2.3

[Timo Sirainen via dovecot]

On 18 Jul 2019, at 11.44, Alessio Cecchi via dovecot  
wrote:
> 
> Hi,
> 
> I have a setup with 3 Dovecot Director v2.2.36 and 
> director_consistent_hashing = yes ;-)
> 
> Now I would like to upgrade to 2.3.7, first only Director and after also 
> Backend.
> 
> Can works fine a ring of director with mixed 2.2 and 2.3 version?
> 
> Mi idea is to setup a new Director server with 2.3, stop one server with 2.2 
> and insert the new 2.3 in the current ring to check if works fine.
> 
> If all works fine I will replace all Director 2.2 with 2.3 version.
> 

There's no known reason why it wouldn't work. But be prepared in case there is 
an unknown reason.