Simply changing auth_cache_size to a non-zero number enables caching, correct?
How big is too big?
Where does it cache it?
Here is what I set:
auth_cache_size = 1048576
I was hoping for 1GB worth of cache.
I have 16GB of memory on the system, so memory is not an issue if it
stores it in memory as opposed to disk.
Dave
Quoting David Cunningham <[EMAIL PROTECTED]>:
Thank you, I will try the caching.
Dave
Quoting Timo Sirainen <[EMAIL PROTECTED]>:
On Wed, 2008-10-08 at 10:48 -0400, David Cunningham wrote:
I agree. In fact, I may have found a DNS issue that may have been
causing login sessions to hang and thus reach max too quickly. The
last few hours have been stable. So, I am keeping my fingers crossed.
I have also recompiled dovecot and changed the setting in db-ldap.h
that reads:
#define DB_LDAP_MAX_QUEUE_SIZE 1024
to
#define DB_LDAP_MAX_QUEUE_SIZE 8192
If you're getting more than 1024 requests queued, something's wrong or
you have hundreds or logins per second. Which one is it? (5000 users
logging in once per minute is still only 83/sec)
The queue keeps increasing if the LDAP server isn't replying to old
requests. So have you looked at the LDAP server side if it's running too
slow?
Anyway two things you could do here:
1) Enable auth cache with large enough size so Dovecot doesn't consult
LDAP server nearly as much.
2) Increase the number of auth processes (auth { .. count=5 }), so that
you'll use more connections and hopefully the LDAP server likes that
better than one connection sending lots of requests. Or maybe not.
