what updates are you referring to?
There are basically two types of updates:
- URL Filter, AV Engine, etc. These updates do not cause an outage, MWG will continue to serve requests. During the update an increased load and memory consumption may be possible, maybe you can share some more details about the used platform
- Appliance update, e.g. the MWG product and operating system. During this update the process is restarted and will not be able to serve requests for a short time. This can be avoided by having multiple boxes and setup a high availability environment
in this case i would suggest a HA Cluster environment. Additional i often deploy a virtual machine as the configuration master. In this case i do the update as followed.
- updating the virtual management appliance
- updating the proxies step-by-step
There is an additional problem with client connections when you are rebooting the appliance. During the shutdown the virtual IP is not removed and for some time internet access is also not possible. But i think there is an FMR for this.