Open Stack

Hi all,

I just wanted to make a note about a couple things here. I'll also try to attend any meeting that is scheduled.

GLSB may be implemented a few ways.​ ​One method is via DNS, as Kunal mentioned. It's not very granular and unless you have very low TTL on your records and the ability to change your records rapidly at the edge, it can be difficult to control.

​A second way to implement ​GSLB is to use Layer 7 to redirect client traffic. Typically you'll tell a load balancer where to redirect traffic and it will do something like an HTTP redirect. I've used this implementation for things like site maintenance, or load based redirection. (I think A10 and F5 implement Layer 7 GSLB solutions in at least some of their products that offer GSLB?)

Something to keep in mind about a DNS based strategy is that recursive resolvers may not respect record order, some implement broken caching (ignoring authoritative TTL values), and that authoritative servers may not be queried evenly.
  
I'd be very happy to discuss specifics offline with anybody that might have questions about authoritative DNS operator quirks, implementations, or what they generally see behavior wise from recursive servers. Otherwise, I look forward to the meeting.

-- 
Tom Cameron  
Network Architect
Rackspace




From: Gandhi, Kunal <kunalhgandhi at gmail.com>
Sent: Friday, May 22, 2015 22:24
To: openstack-dev at lists.openstack.org
Cc: dougw at a10networks.com; v.jain007 at gmail.com
Subject: [openstack-dev] [designate] and [lbaas] - GSLB API and backend support
  
Hi All


I wanted to start a discussion about adding support for GSLB to neutron-lbaas and designate. To be brief for folks who are new to GLB, GLB stands for Global Load Balancing and we use it for load balancing traffic across various geographical regions.  A more detail description of GLB can be found at my talk at the summit this week here.


To my understanding, there are two sides to a GSLB - DNS side and LB side. 


DNS side
Most of the GSLB’s provided by various vendors are DNS servers and are authoritative for the GLB domains. The global fqdn’s that belong the GLB domains resolve to multiple public VIP’s  across various regions based on various configurations on the global fqdn on the GLB.


LBaaS side
A few of the common functionalities provided by a standard GSLB provides are health monitoring on the public VIP’s and the local LB’s on which these public VIP’s sit on. Some additional  features that a GSLB can provide are configuring admin status and weights on your public VIP’s. Based on these configurations and settings, the GLB returns the appropriate number of public VIP’s to any DNS resolve queries for the global fqdn’s.

I would like to have the designate and lbaas to start a discussion on GSLB and discuss the following topics:

What parts of GSLB belongs to Designate and LBaaS ?
Once we have an understanding of the above, my team at eBay/PayPal would like work with the community on submitting a blueprint for this.

To kick start this conversation, I would like to schedule an irc meeting regarding this with folks from designate and neutron-lbaas. Please let me know a time and day that works for you guys. I am available on Thursday and Friday next week.


Regards
Kunal