Re: High-volume server settings

[Xueshan Feng <sfeng@stanford.edu>]

----- "Dmitry S. Makovey" <dmitry@athabascau.ca> wrote:

| On February 17, 2009, Xueshan Feng wrote:
| > Dmitry,
| >
| > We have 8 mailbox servers, 3 ldap severs. Each server has around
| 5000
| > accounts. Hardware is on Dell 1950 with 16GB memory. Our Zimbra
| store and
| > backup partitions are on NetAPP SAN disks.
| >
| > Since you got http errors, you might want to look specifically  if
| you have
| > lots of ldap timeout in /opt/zimbra/log/mailbox.log file.
| 
| that was a great suggestion which I went and checked out right away. 
| Unfortunately the only thing in the logs that seems to be related to
| LDAP is 
| Zimbra's fall-back to internal Auth. Do you, by any chance have
| message 
| you've seen handy, or maybe remember what it was about? Ours
| definitely has 
| nothing with word LDAP in it that is of any value.


It's lot of Java errors with key words like this:

com.zimbra.common.service.ServiceException: system failure: ZimbraLdapContext
....
...

Caused by: javax.naming.NamingException: LDAP response read timed out, timeout used:30000ms

Also, if you use what your tcp stack, you will lots of TCP established connections hanging around, won't go away.

Xueshan


| 
| > In our load testing, we ran into ldap timeout issue which translated
| to
| > http errors.  We ended up turning off tls between Zimbra mailservers
| and
| > Zimbra ldap servers ( zmlocalconfig -e ldap_starttls_supported=0 ).
| Because
| > Openldap connection pooling is not supported for TLS connections,
| tuning
| > TLS off enables connection pooling and gives better performance
| there.
| 
| doesn't seem to be the case *now* but it's a great tip for the future
| 
| references, thanks.
| 
| > Also, "zmstat-chart" is very useful for trouble-shooting
| performance
| > problem. We run it every 20 minutes and the chart is automatically
| posted
| > on a website to help analyze problems and to measure tunning
| result.
| 
| so far we can't find a single thing to pin our problems on. Even with
| 
| zmstat-chart - things seem to be well within their limits (well at
| least in 
| comparison to what we had prior to migration)
| 
| > Here is our configuration script:
| 
| big thanks for that. That is definitely something I was looking for 
| to "compare notes" on installation and setup.
| 
| 
| -- 
| Dmitry Makovey
| Web Systems Administrator
| Athabasca University
| (780) 675-6245