Cloud Ping-Pong: Passing VM Workloads from Cloud to Cloud Will Hurt
Douglas Gourlay wrote an excellent post yesterday over on Cisco’s Data Center blog about what doesn’t work in the current cloud model. He had two great points. Point one:
And the most important point, about Cloud Computing is that it is in the cloud. and the cloud is the Internet.
This, to me, is one of the fundabmental problems with cloud computing that we need to address from the get-go, and why initiatives like Infrastructure 2.0 are catching on so quickly. We’re moving critical applications — and the back-end tools to mange them — out of our isolated, sadboxed, controllable enterprise data centers and on to the public internet. When someone in the office needs to access their newly-clouded sales app, they’re competing with upstream bandwidth against everyone else in the office catching up on YouTube and Twitter.
And the 2nd is in the comments:
Many people are astounded at the amount of data transmitted to support video, but that may be dwarfed by the movement of VMs.
Wow, that may be the best example to sum up the challenges with portable workloads I’ve read. Video streams content in a very deliberate way, video can buffer, video has bandwidth negotiation built in; copying straight VMs over TCP doesn’t, barring a technology on top of the connection for rate shaping. Pushing fully bundled vApps from vCloud to vCloud, with clusters of GB-sized VMDKs, across the public network is going to bring a whole new scale to “Start copy, get coffee.” How these issues are dealt with from the DR and SLA perspective is going to be interesting.
Check out the rest of Doug’s post for the details. I’m exercising brevity on this cold Friday morning.
January 9th, 2009 at 8:54 am
Nice Post! This does a great job describing the potential pitfall of moving virtual machines to the cloud.
January 10th, 2009 at 3:41 am
These are certainly issues that will need to be addressed.
From the bandwidth to the cloud side managing traffic quality is a mature technology. Industry already is doing this for much more difficult protocols such as VoIP. Also Internet may not always be the access medium to the Cloud, we will see a lot of dedicated networks too. This is also why we will see a greater reliance on WAN acceleration technologies which Cisco are pushing as import to pair with Cloud adoption.
Certainly very true on the bandwidth side and I don’t want to distract from that. However in the early generations we are probably not going to see VMotion and dynamic and move of workloads around across clouds. This is certainly not what the vCloud API will provide. What we will see though is cloud providers who will may do it internally for you, for purposes of DR and their own backend scale. They can do it because they probably own the carriage. In future generations we may see this start to occur, but bandwidth is going to have to catch up. Just think back 5 years and what bandwidth we were all living with. Remember 128K frame relay links, don’t see them much any more.
Great discussion.