aphyr

43 ms·

391.
by aphyr 14y ago
Ah, I didn't intend for this post to reach Hacker News absent context. If you haven't been tracking Riemann, this post might not make sense. ;-) Riemann is not an HTTP server, or anything analogous. It's an event processor, and reacts to in
392.
by aphyr 14y ago
This is good advice in general, but Rails used the wrong kind of parser for this kind of data. JSON is not YAML. A YAML parser does not provide the same guarantees as a JSON parser about its output. It doesn't matter if both parsers are c
393.
by aphyr 14y ago
by the open admission of sexuality I agree with you; "partner" has an unusual feel in conversation, and I'm never sure what to make of it. I think for some folks this is a sore spot--that the phrase "wife", spoken by a man, is also an o
394.
by aphyr 14y ago
Riemann is a giant ball of mutable state and IO, and makes extensive use of the STM: https://github.com/aphyr/riemann/blob/master/src/riemann/str... The critical thing, as you observed, is to separate IO from retryable STM transactions wi
395.
by aphyr 14y ago
I'd like to contrast this: if your application is heavily dependent on state, especially state which is shared between threads, Clojure offers a concise, safe, and uniform way to understand and organize state transformations--at the cost
396.
by aphyr 14y ago
I know you're being sarcastic, but this is a wonderful thing about science! Commonly held, intuitive, time-honored ideas about temperature, space, mass, time, turn out to break down in edge cases, and those breakdowns drive the development
397.
by aphyr 14y ago
No. Temperature is just the relationship between entropy and energy: ∂S/∂E. This relationship can be negative.
398.
by aphyr 14y ago
No, it's not... really nonsense--it's just really confusing if you haven't worked with entropy and canonical ensembles before. See my comment above, or http://en.wikipedia.org/wiki/Thermodynamic_beta .
399.
by aphyr 14y ago
Temperature is conventionally defined as the average kinetic energy of a collection of particles. Many thermo and statmech texts will use this phrase as an operational definition for temperature in idealized kinetic models, but the conven
400.
by aphyr 14y ago
There are protobuf bindings for many languages, though I hear node.js was a bit of a pain. Check the clients page and see if the language you need is there; I can help you build one if not. For pulling from other tools, I usually write a li
401.
by aphyr 14y ago
Thank you. :)
402.
by aphyr 14y ago
Ah, yeah I should standardize the docs a bit. It'll be clearer when you've looked at the stock config: (streams ...) just denotes the section of the config where streams live. Since most streams are composable, I sometimes omit the context.
403.
by aphyr 14y ago
Riemann originated as a system for discrete calculus over metric streams; e.g. Riemann sums.
404.
by aphyr 14y ago
1. The dashboard is in a rough spot right now--I haven't quite finished the transition to the next-gen dash--but it does do "realtime" visualization of events matching arbitrary queries with under 50-ms end-to-end latency. It'll push about
405.
by aphyr 14y ago
You're right to be concerned about complexity: simple things are easy to understand, easy to predict, and easy to change. That said, I think you'll find many of the ideas in Riemann to be radically simple. The config file is just a Clojure
406.
by aphyr 14y ago
I'd like to add to this: Riemann is more opinionated than Esper. While you can use it as a general event processing system, it makes some assumptions about event structure which are geared towards application monitoring. For instance, Riem
407.
by aphyr 14y ago
Thanks for your interest everyone. I'll try to answer any questions here. Going through some rough health stuff at the moment so I won't be on IRC, but I do read the backlog and will respond when I get a chance. Cheers! :)
408.
by aphyr 14y ago
Hi, I'm the author of Riemann. This part of the documentation is aimed at people who already know what Riemann is, so your confusion is completely understandable! :) In short, Riemann is a complex event processor, driven by Clojure configur
409.
by aphyr 14y ago
7 times sounds atypical; perhaps by changing your driving behavior you could reduce your risk. You might try decelerating slowly, keeping 2-4 seconds of following distance, checking your rear-view while braking, and leaving extra space in f
410.
by aphyr 14y ago
CSRF won't protect against traffic sniffing; only third parties constructing URLs.
411.
by aphyr 14y ago
AOL does a lot of weird things. Last year, jrecursive actually observed that their servers would make an HTTP GET for any URL passed over an AIM conversation. Looks like that doesn't happen any more, though.
412.
by aphyr 14y ago
The walkthrough took me through finding a correlation between voting preference and neuroticism. Great! But it's also worth noting that this dataset shows larger effect sizes at similar CIs for the correlation between [preference and age]
413.
by aphyr 14y ago
I answered "Ruby" on the survey without question: in my case, it has significantly broader applicability than Erlang. In more general terms: no, I don't see this as a critical methodological error. Could it be "Pick your top n"? Sure, might
414.
by aphyr 14y ago
Different techniques are useful for different problems. Sometimes you really want a powerful type system: it makes invariants for safety, concision, and speed available that you can't get any other way. Other times you want a more dynamic
415.
by aphyr 14y ago
Prior to Clojure, my primary languages were Ruby and Erlang. Where Clojure or Java libraries are available, Clojure is typically a functional superset of Ruby. Blocks are used as weak macros, that sort of thing. Erlang/OTP is pretty unique
416.
by aphyr 14y ago
The idea of having a primary language honestly comes off to me as a sign that the developer hasn't spent much time programming yet: the real world has so many languages in it, and many times the practical choice is constrained by that of t
417.
by aphyr 14y ago
Minor note: Clojure's STM applies to any number of variables.
418.
by aphyr 14y ago
I agree. The future of server programming is also not spawning multiple child processes. The question I have is how far off is that future? I know that most of my web applications today simply run in multiple spawned OS processes. Barring
419.
by aphyr 14y ago
Erlang and Clojure are multithreaded. Clojure offers full access to Java-style (Thread. (fn [] ...)), j.u.c Executors, and Clojure-specific threadpools for agents and futures, including differentiation between CPU and IO intensive threads.
420.
by aphyr 14y ago
Note--think I'm wrong about these types of process switches requiring a TLB shootdown. It think it's just cache invalidation.

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