The issue appears to be related to zimbraHttpNumThreads which was set to 250. We have increased this to 500 and performed a restart of the Zimbra service on the server concerned. We have also implemented an additional MRTG graph to monitor this metric. Our servers are performance tuned in accordance with Zimbra's best practise guidelines, although this specific setting is not manditory and the guidelines are slightly ambiguous as to what value is most appropriate.
We have received reports from two resellers that Outlook users are experiencing connection issues. At this stage we are unable to recreate these problems, but beleive that it might be related to Zimbra Proxy - a service which we enabled some weeks ago and which manages the distribution of incoming connections to the appropriate backend mailbox server. We are currently running extended debug logging to attempt to identify this issue. In the mean time, please ensure that your users access via the correct server name as defined in the set-up instructions.
On Saturday the 28th of March at 9PM (GMT) we will be installing a new SSL certificate on our Zimbra platform. This certificate will replace the current one which is due to expire in early April. Zimbra will be unavailable for a short period of time during the installation.
Maintenance Start: 21:00 (GMT) 28th March 2009
Maintenance End: 21:30 (GMT) 28th March 2009
Although 30 minutes has been set aside, installation should take no more than a few minutes.
During the maintenance window all incoming email will be queued, access to the Zimbra servers will be restricted and Zimbra customers will not be able to access their mailboxes.
All maintenance announcements, service issues and notifications will be published here. There are various ways to monitor this information - you can subscribe to this blog, follow @itnet_noc on Twitter or subscribe by RSS. Whenever we publish something here, it will also be auto posted to our corresponding Twitter timeline.
