ZCS Administrator Guide 8.0

Open Source Edition

Proxy Architecture and Flow

The following sequence describes the architecture and flow of Zimbra Proxy.

1.	End clients connect to Zimbra Proxy using a POP or IMAP or HTTP requests to a backend server. Nginx handles the incoming POP and IMAP requests.

2.	When Zimbra Proxy receives an incoming connection, Nginx sends an HTTP request to the Route Lookup Handler, a servlet located on the mailbox server. this servlet processes the server and port informatin of the user account.

3.	The Route Lookup Handler locates the route information for the account and returns this information to Nginx.

4.	The Memcached component stores the route information for a configured period of time. By default, this time is one hour. Nginx uses this route information until the time expires, instead of querying the Route Lookup Handler.

5.	Nginx uses the route information to connect to Zimbra Mailbox.

6.	Zimbra Proxy connects to Zimbra Mailbox and initiates the mail proxy session. The end client behaves as if it is connecting directly to Zimbra Mailbox.