Hybrid Clouds Require Significant Network Attention!
When an enterprise adopts a Hybrid Cloud configuration and positions compute and storage resources in the cloud, the network connecting the cloud to the enterprise LAN becomes a critical link. The Cloud can be viewed as another data center location for the enterprise from a network perspective. So, the connectivity to that data center needs to be:
1. Highly Available
2.Highly Performant – minimal latency
To achieve High Availability, the enterprise needs to implement a multipath configuration using separate network providers on disparate physical paths. This will eliminate any single point of failure and the disparate physical paths will protect against the errant backhoe accident! The firewall configuration should also be redundant with intelligence to provide automatic failover from one path to the other in the event of connectivity loss.
For performance, the enterprise needs to keep two principles in mind:
1.Keep the processing instances as close to the data as possible
2.Move the data as little as possible
Ideally, the bulk of the network traffic between the cloud and the enterprise LAN will be user/client traffic. Most applications use a browser interface today, so that traffic will be predominantly HTTP sessions between the user’s browser and the processing instance in the cloud.
Some amount of data may be generated on the enterprise LAN and must eventually be processed by cloud instances. In that scenario the data should be moved to the cloud before processing. That can be accomplished most efficiently using storage based replication scheduled for off-hours or with a local cache that continuously moves data to the cloud as small transactional amounts in a net-change model.
With the cloud serving as a data center, the enterprise also needs to consider the TCP/IP addressing model at the outset. The cloud is typically connected to the enterprise LAN with persistent VPN connections, so the TCI/IP addressing for the cloud instances must be compatible with the enterprise LAN TCP/IP addressing model – just as if the data center were actually on premises and part of the enterprise LAN.
The Cloud can be an efficient and flexible data center for the enterprise but must be planned as if it were on premises. With mission critical applications residing in the Cloud, the connectivity model must also eliminate single points of failure to ensure uninterrupted business processing.