Racing to Zero Latency - blog.gigaspaces.com 

If the definition of the term 'latency' is the overhead of the underlying infrastructure, and the definition of the term zero is that it is a number that is not necessarily zero, then indeed, we can conclude that the impossible goal of zero latency has been achieved.

In fairness, Gigaspaces Shay Hassidim demonstrates how a memory based data store (IMDG) can wipe the floor with more traditional disc-based access systems when it comes to minimizing latency. 

"Relational databases are designed and optimized for commodity disk drives. Even if you run a relational database in-memory, the code and internal structures are not optimized for operation in an in-memory distributed environment.

"There is some progress lately leveraging Solid-state drive (SSD) products, as alternatives to the commodity disk devices, but, still, relational databases are monolithic servers which can't operate in a distributed environment taking advantage of the entire network resources and scale in an elastic manner."

Obviously, the comparison is a bit self-serving, coming from a company that prides itself on delivering a highly competitive product in the memory based data store space, but the self-serving nature doesn't diminish the validity of the results.

"When taking into consideration the average time is takes to consume data from the IMDG, the time it takes the business logic to process the incoming data and digest it into meaningful output data, and later to preserve it to survive system failures, we see that the actual impact of the IMDG on the overall business transaction latency is between 2-10 percent (around one millisecond). This is a constant overhead regardless the IMDG size, application size or the data model complexity.

"Comparing this overhead to a file based system where the overhead starts with 20ms and can end up with 5000 ms latency (3 orders of magnitude larger than IMDG!), we can say we have almost zero latency overhead with the IMDG. Thus, the zero latency "impossibility" is now a reality!"

I'm sure a logician would have an issue with the final conclusion. "We have almost zero...thus zero is now a reality." Still, the demonstration of the power of IMDG is noteworthy.

Racing to Zero Latency - blog.gigaspaces.com