[imp] New IMAP server, troubleshooting slow IMP performance

[Jan Schneider]

Zitat von Simon Wilson <simon at simonandkate.net>:

>>>> Hi Simon,
>>>>
>>>> On Wed, Jul 26, 2017 at 12:07:26PM +1000, Simon Wilson wrote:
>>>>> I've just moved over to a new IMAP server on my local network,  
>>>>> migrating IMAP
>>>>> from a CentOS 5 to a CentOS 7 server in the process.  
>>>>> Horde/apache are on a
>>>>> separate server on the same network as both the old and new IMAP servers.
>>>>>
>>>>> I'm trying to troubleshoot laggy performance in Imp since the move.
>>>>>
>>>>> For example, refreshing the mail list in Inbox and deleting an email each
>>>>> take 3 to 4 seconds before the Refresh circle stops spinning and  
>>>>> the list is
>>>>> updated. This is longer than it was before (1 to 2 seconds typically). It
>>>>> just means that overall Imp feels very slow.
>>>>
>>>> Just a few ideas:
>>>>
>>>> - Is your imap server respongding slow if you connect with another mail
>>>> client, for example Thunderbird?
>>>
>>> No - feels very snappy from Mailbird.
>>>
>>>> - Are other php scripts on your webserver where imp is running also
>>>> reacting slow?
>>>
>>> No. WordPress, which is hosted on the same server as Horde, is  
>>> performing as normal. I also have a custom PHP app running on that  
>>> box, and it's lightning fast. The Horde server is not highly  
>>> loaded, CPU usage avg < 5%.
>>>
>>>> - Are the cache settings for horde and imp the same as they were in the
>>>> old setup?
>>>
>>> I've not changed anything on the Horde server except pointing Imp  
>>> and Ingo backends.local.php to the new IMAP server address. I also  
>>> rebooted it.
>>>
>>>> - Are the network settings, especialy routing and DNS, on the new
>>>> webserver really OK?
>>>
>>> The web server has not changed at all, Horde and httpd are  
>>> unchanged (apart from the changed config to point to the new IMAP  
>>> server), only IMAP has moved. The server IMAP has moved to is  
>>> running well - again very low CPU, 4GB RAM. It runs postfix,  
>>> cyrus-imapd, associated mail filters, and nothing else. It's not a  
>>> high traffic mail server.
>>>
>>> It's only Imp that appears sluggish when pointing at the new IMAP  
>>> server, yet the transactions appear to be fast from the IMAP IMP  
>>> debug log. Maybe I'm imagining it... but my seat of the pants dyno  
>>> tells me it's slower... :)
>>
>> Did you try emptying the IMAP cache, assuming you have it enabled?
>>
>
> Jan - IMAP cache... the caching I had setup was:
>
> $servers['imap']['cache'] = sql;
>
> I just switched it to nosql to use the mongo nosql setup on the  
> server that is used for Horde cache - and the email times have  
> dropped to about 0.5s.
>
> Thanks Jan, that was the ticket. I think nosql is probably better  
> performance anyway?

Probably yes.

-- 
Jan Schneider
The Horde Project
https://www.horde.org/