Memory-Based Architectures and the Cloud

Todd Hoff at HighScalability.com published another excellent article entitled Are Cloud-Based Memory Architectures the Next Big Thing? Chock full of analysis, data, links, examples and references. IMHO, it's a must-read piece for developers and architects.

As I noted in the comments to Todd's post, in addition to the many benefits of memory-based architectures which Todd lists, there is also the cost benefits in the cloud, which I discussed in Cloud Pricing and Application Architecture.

An excerpt from Todd's piece:

       

RAM = High Bandwidth and Low Latency

Why are Memory Based Architectures so attractive? Compared to disk RAM is a high bandwidth and low latency storage medium. Depending on who you ask the bandwidth of RAM is 5 GB/s. The bandwidth of disk is about 100 MB/s. RAM bandwidth is many hundreds of times faster. RAM wins. Modern hard drives have latencies under 13 milliseconds. When many applications are queued for disk reads latencies can easily be in the many second range. Memory latency is in the 5 nanosecond range. Memory latency is 2,000 times faster. RAM wins again.

       

RAM is the New Disk

The superiority of RAM is at the heart of the RAM is the New Disk paradigm. As an architecture it combines the holy quadrinity of computing:

Performance is better because data is accessed from memory instead of through a database to a disk.

Scalability is linear because as more servers are added data is transparently load balanced across the servers so there is an automated in-memory sharding.

Availability is higher because multiple copies of data are kept in memory and the entire system reroutes on failure.

Application development is faster because there’s only one layer of software to deal with, the cache, and its API is simple. All the complexity is hidden from the programmer which means all a developer has to do is get and put data.

Read the whole thing.