[horde] Problem of slow with server-side sorting

[Rick Romero]

Quoting "Andrew Morgan" <morgan at orst.edu>:

> On Fri, 5 Jun 2009, Jose Luis Marin Perez wrote:
>
>> I increased the RAM to 2 GB and there is a small increase to  
>> improve service.
>>
>>
>> Based on the commentary of Andreas, I have noticed through IOSTAT (%
>> util) the Disk I / O is high and reaches 100 when using any of these
>> webmail accounts that have more than 1500 messages
>
> <snip>
>
>> The question is whether there is any special configuration in Horde  
>> or Courier-IMAP for not saturating the Disk I / O.
>>
>> If you increase the RAM can help with anything?
>
> Maybe this was already covered earlier in this thread - Do you see  
> the same poor performance with large mailboxes if they use a  
> stand-alone IMAP client, such as Thunderbird?  You should record  
> iostat numbers for that case as well.

The only problem with that test is some of those clients will store  
mail locally 'offline', creating their own indexes and such and  
offloading the job from the server.

>
> That might help us narrow down if the problem is caused by Horde or  
> if it is a problem with any IMAP client.

I think it's Courier-IMAP.  I had general slowness issues with large  
mailboxes using Courier until I upgraded to Dovecot.  Dovecot has an  
index for each folder, and the first time I did a search from Horde it  
came back almost immediately.  I was astonished at how fast a search  
was.  I was expecting it to take a while.

Rick