Hacker Newsnew | comments | ask | jobs | submitlogin
bmohlenhoff 1058 days ago | link | parent

It sounds like a neat project, but I think describing it as "real time" is misleading if you're not also providing information on latency. The majority of the provided use cases seem to indicate a high level of scalability and durability, as well as a high level of throughput, but these are not necessary characteristics of a true real time system.

It's a common misconception. A real time system doesn't have to be fast, efficient, or fault tolerant. A real time system must guarantee with 100% certainty that in all cases it will respond to input X within a time period of Y.

I would be interested to learn the timing issues driving the development of this system and how you've guaranteed such a response time, especially given that it's running on top of the JVM and must therefore deal with a non-deterministic garbage collection process.



scott_s 1058 days ago | link

You described a hard real-time system. That exists for things like the controllers on a jet. What's becoming much more prevalent are soft real-time systems that perform analytics. There won't be any catastrophic failure if deadlines aren't meant - and there may not even be any expressed deadline - it's just understood that the data must be processed and analyzed as fast as possible to be useful.

-----

bmohlenhoff 1058 days ago | link

I certainly did describe a hard real-time system. It's nice to see that other people recognize the distinction.

Every time I see a post describing a "real time" system I always read into it hoping that what they are describing is a hard real time system, because they are neat, but they never are, probably because they are so difficult and expensive to build. Also I guess they aren't the most relevant type of system for the majority of people here, who are dealing (as you say) with customer-facing front ends.

-----

nathanmarz 1058 days ago | link

Yes, Storm is more intended for soft realtime problems.

-----




Lists | RSS | Bookmarklet | Guidelines | FAQ | DMCA | News News | Feature Requests | Bugs | Y Combinator | Apply | Library

Search: