Virtualizing the Edge
There is no question WAN optimization technology was a game changer. It took away a major pain point for the most popular and common protocols that suffered noticeable performance degradation over WAN connections. While the technology has been very successful in optimizing specific traffic types, there are others that have remained underserved, most notable are write-intensive workloads such as CAD files and custom applications. Applications and data that cannot be optimized require local servers and storage at the branch. This creates a number of problems for IT in the area of security, support, and management. Enterprises looking to consolidate branch office equipment and centralize data for both security and control are stuck between a rock and a hard place.
On February 1st, Riverbed rolled out a new technology dubbed Granite. Granite looks to address these issues and herald in a new era in WAN optimization. Granite is not WAN optimization technology, but rather it is something new. It is a bridging technology that enables local storage caching of large chunks of data on edge servers in the branch while the data remains in the datacenter. Riverbed refers to this as its Edge Virtual Server Infrastructure (Edge-VSI). Riverbed Granite allows data to reside centrally, yet be available to edge servers as if it were local. Riverbed Granite tackles the problem low in the technology stack: at the block level using what Riverbed has trademarked BlockStream technology. Granite parallelizes interactions between the server and storage rather than relying on a sequential approach. A sequential approach requires sending one block at a time in sequential order. This can be slow and cause applications to time out over WAN links. The Granite approach uses a predictive algorithm that can send the entire batch of blocks at one time.
Granite consists of two components – one located at the datacenter and the other at the remote branch:
- Granite Core – a physical or virtual appliance that resides in the data center alongside centralized storage.
- Granite Edge – a service that resides at the remote branch and is available as a standalone appliance or bundled as a service on the new Riverbed Steelhead EX + Granite appliance.
Granite Core mounts LUNs provisioned in the data center and shares the storage resources with branch offices running Granite Edge. Granite Core inspects mounted LUNs and proactively streams data to the branch locations. Granite Edge ensures that data created in branch office locations is securely stored in the datacenter. The data between the Core and Edge solutions is encrypted. Granite Edge virtually presents iSCSI targets for use in the branch. The Granite Edge has a full working set of data, so there is a 100% hit rate on all reads and no cache misses. So if the WAN link goes down, users will still have access to the data. This is not LAN-like performance – it is LAN performance. Also, there is the option to proactively ‘pin’ a LUN on the Granite Edge device, so that driving application is linked to that storage LUN, thereby reducing the round trips between the branch and datacenter. The Granite Edge can hold up to 4TB of data (on both the hardware and software versions). The Granite Edge then pushes updates through a periodic sync back to the datacenter. So formal backup procedures are not necessary at the branch.
In addition to the Granite announcement, Riverbed introduced two new Steelhead models – the CX and EX. The CX is a dedicated WAN Optimization only, hardware appliance platform and the EX series is the multi-function, branch office appliance that will be a consolidation point of networking infrastructure at the branch. The EX model is evolving to be a consolidation point for the virtual compute platform, now called VSP (nee RSP) and Riverbed’s growing product portfolio. There is an additional model, the EX + Granite, which includes the Granite Edge service on the appliance. One important feature of the EX line is that they all have on-board solid-state disk, which is a requirement for the Granite data projection capabilities. The datacenter component Granite Core needs to be purchased separately. These new models are expected to begin shipping later this quarter.
It would appear in the near term that both network and branch virtualization will happen in bits and pieces. It is clearly going to take place in the form of consolidation first especially at the branch. Real estate in the branch is at a premium and with a directive to centralize data back in the datacenter infrastructure managers will be looking for ways to make that happen. Riverbed is willing to stand up and say in some cases WAN optimization, as we know it today, is not good enough – there are some use cases it does not address. Granite is more of a storage play than a network one, so Riverbed will need to continue to work with the major storage vendors to develop proof of concepts and win over a new audience. However, over the last two years Riverbed has clearly demonstrated their willingness to explore new tangential markets and push the envelope. The transition towards making Steelhead boxes a broader solution play in the branch has not been well received by all of Riverbed’s customers. The introduction of new models represents a separation of church and state, WAN only and multipurpose platform, to quell criticisms from purists who want WAN optimization only on their Steelhead appliance. It would appear that Riverbed is addressing some unrest in their customer base.
Granite is something new, Riverbed has applied for a patent on the technology, and it embodies both a new opportunity and a bit of a risk. Granite looks to address what has been a limitation to the existing WAN optimization techniques that Riverbed deploys. If Riverbed can make it work, it will be a boon to the business and open up new opportunities not previously available. If it is a bust, naysayers will have a field day. So far Granite has been well received in beta tests and these will give Riverbed a whole new set of use cases for their technology. It is not often we get to see innovation in a mature technology market. Granite is innovative and it can be a game changer for WAN optimization and help drive further branch consolidation. I look forward to seeing how this plays out.