[Dovecot] Dovecot performance under high load (vs. Courier)

[Ed W]

On 23/06/2012 09:22, Wojciech Puchar wrote:
>>> Nearly all of them are non-caching. (I don't know of any caching ones.)
>>
>> At least roundcube (v0.7.1 here) has some caching options:
>>
>> ------------------[excerpt from roundcubes main.inc.php]-------------
>> // Type of IMAP indexes cache. Supported values: 'db', 'apc' and 
>> 'memcache'.
>> $rcmail_config['imap_cache'] = null;
>>
>> // Enables messages cache. Only 'db' cache is supported.
>> $rcmail_config['messages_cache'] = false;
>> -------------------------[end]----------------------------------------
>>
>> But I don't know, whether this is the sort of caching you are 
>> referring to.
>
> what's a point of caching imap, except your webmail service is not 
> locally connected (localhost or LAN) to imap server?

Asking for items 600-615 from a threaded list, sorted by something, can 
be an expensive operation, especially if you just asked for items 
585-600 a moment ago?

Ed