Web Hosting Maintenance - Proxy Server Change

Thu, 10/28/2010 - 13:41 — Sean Yo

Web Solutions will be making changes to our web proxy service this coming Saturday.   These changes will make our organizational web hosting service more reliable and scalable.

NB: Historically we’ve called this service the web proxy service, which doesn’t differentiate between  proxy and reverse proxy.  This service is a reverse proxy, also known as a web gateway; for better clarity and precision we will now be referring to this service as the “web gateway service”. 

What is a web gateway server?

  • A web gateway server sits in front of our backend web servers and allows us to direct traffic with server configuration, which is able to update immediately.  This lets us easily and quickly route requests to a backend server without needing the wait for a DNS update.  This service helps the web hosting service be very agile and very flexible.
  • This service allows us to
  • consolidate multiple servers behind a single or group of domains
  • centralizes configuration management
  • provides greater security by allowing public access only on the web gateway servers

What’s Happening?

  • The web gateway service on proxy.web.uoguelph.ca is being migrated a load balanced cluster.
  • The service name “proxy.web.uoguelph.ca” is being assigned to the Load Balancer service.
  • The Load Balancer service is run by the CCS Networking Services Team.  Our thanks to them for their help and support.
  • This will balance the load of web traffic for this service across all web gateway servers and removes a single point of failure from our web hosting service.
  • This service is being moved from physical hardware to virtual systems, providing additional benefit to the service’s reliability and scalability.
  • A new configuration process will be put in place which automates testing and deployment of our web gateway servers
     

How Is this being done?

  • We will be making a series of DNS changes to repoint proxy.web.uoguelph, and any Zone-Level domains with an ARECORD pointing to proxy.web’s IP address.  All of these domains will be configured to point to the CCS Load Balancer.
  • We have exhaustively tested this new configuration and have very high confidence in this migration
  • We will keep the previous hardware available to allow for a simple and very fast roll-back, if needed
  • We will be monitoring both the new and the old servers for several hours after the change and then intermittently over the remainder of the weekend and on Monday. 
     

What will look different after the change?

  • Nothing! 
  • These changes are to the infrastructure of the organizational web hosting service.  This service update has been design to not affect or impact any visible part of the web sites we host. 
  • What is changing is the robustness and failure-tolerance of this service.

What Do I need to do?

  • Nothing!
  • There are no required actions by campus web developers
  • If you are a campus web developer and would like to see your site on the new web gateway servers before the migration, contact Sean Yo (sean.yo@uoguelph.ca ext. 54315).  It is simple and will be boring – because nothing will look different :)
  • If you are a campus web developer and want to test your site after the migration, we will post to the CCS Service Updates, found on the front page of the CCS web site (http://www.uoguelph.ca/ccs/) when the migration is complete.  Please be aware that we will be testing every site on our service on our own.  However, you are welcome to conduct your own testing as well.  In the unlikely case you encounter a problem, please contact Sean Yo directly by email at sean.yo@uoguelph.ca