[horde] Apache Performance tuning with Horde

[lst_hoe02 at kwsoft.de]

Zitat von Patrick De Zordo <patrick at spamreducer.eu>:

> First:
> Our test server is located in a shared datacenter and we are using a shared
> SAN storage as our backend.
> We have checked the bandwidth of the storage using some simple tools like dd
> and htparm..
> The storage has a LOT of bandwidth and a lot of IOPS.. so there should be no
> problem.

Is this some consumer grade VPS or do you have a SLA?

Shared storage can be slow at unexpected times as it is shared, so it  
depends what others are doing

Shared storage is sometimes really fast for data in the cache but  
dreaded slow for not often used data

> Second:
> During the apache CPU load spikes we are monitoring our system with dstat
> and iotop and we can't see any big disk reads or writes.
> We just see our CPU going up to 100% for about 4-6 seconds after every
> little ActiveSync synchronization a client is making.

Do you have a dedicated vCPU or some shared container? (We have one  
cheap VPS with a vCPU limited to 380MHz...)
Is Apache the only one consuming high cpu percentage?
Is Horde configured to use caching?
What database do you use?

> For example, marking 10 messages as read will cause it. Clients Outlook is
> signaling waiting for server answer..
>

Outlook has numerous issues you can see in the list archive. What is  
happening with some mobile client?

Regards

Andreas