4 ms·

I'm surprised that dynamic backend management is based on Redis. This seems very heavyweight. Why not just a simple HTTP API?

jerf 11y ago
While I'm sure someone, somewhere in the world has it, it would be an odd use case where the "heavyweightness" of the run-time configuration interface actually matters to anyone. And, well, actually, if I had to bet, I'd bet Redis is actually lighter weight than an HTTP request, honestly. HTTP is really quite inefficient for small requests, and requires a massive pile of code to deal with endless, endless corner cases than an application-specific protocol doesn't.
- 15155 11y ago
  > I'd bet Redis is actually lighter weight than an HTTP request It is. Here's a cool, non-relevant example of one implementing a Redis clone in Haskell (on HN a month or so ago): https://honza.ca/2015/09/building-a-redis-clone-in-haskell https://honza.ca/2015/09/building-a-redis-clone-in-haskell The relevant portion is where they parse the protocol, not bad at all (especially compared to HTTP)
  - derefr 11y ago
    I wouldn't compare Redis pub/sub on a persistent Redis socket to straight HTTP requests; it's more like an HTTP Server-Sent-Event stream, which looks pretty similar at the protocol level.
nicolaslem 11y ago
Redis in Pub/Sub is quite lightweight in fact. It's just a TCP connection between your application and the Redis database. Once opened, you can get notifications almost for free. I was thinking on adding a separate HTTP API to control the load balancer that would read and write to Redis, notifying the load balancer when changes should be applied.
- dave_ops 11y ago
  But it's a SPoF and an extra remote or local service that has to be configured, maintained, etc. The thing that's coming online has to publish a message to redis anyway, so why not just maintain the service map inside the Rust application and open up a socket that allows those things to speak straight to Nucleon for mutating its configuration?
  - michaelmior 11y ago
    That's more what I was getting at, not "heavyweight" in the sense that I see it as a performance concern.
  - michaelmior 11y ago
    That's more what I was getting at, not "heavyweight" in the sense that I see it as a performance concern.
- halayli 11y ago
  What happens if your connection to redis dropped and a pub was made in between?
jedisct1 11y ago
What not NATS instead? There's even a very nice Rust client library for NATS :)

jerf 11y ago

While I'm sure someone, somewhere in the world has it, it would be an odd use case where the "heavyweightness" of the run-time configuration interface actually matters to anyone. And, well, actually, if I had to bet, I'd bet Redis is actually lighter weight than an HTTP request, honestly. HTTP is really quite inefficient for small requests, and requires a massive pile of code to deal with endless, endless corner cases than an application-specific protocol doesn't.

15155 11y ago
> I'd bet Redis is actually lighter weight than an HTTP request It is. Here's a cool, non-relevant example of one implementing a Redis clone in Haskell (on HN a month or so ago): https://honza.ca/2015/09/building-a-redis-clone-in-haskell https://honza.ca/2015/09/building-a-redis-clone-in-haskell The relevant portion is where they parse the protocol, not bad at all (especially compared to HTTP)
- derefr 11y ago
  I wouldn't compare Redis pub/sub on a persistent Redis socket to straight HTTP requests; it's more like an HTTP Server-Sent-Event stream, which looks pretty similar at the protocol level.

nicolaslem 11y ago

Redis in Pub/Sub is quite lightweight in fact. It's just a TCP connection between your application and the Redis database. Once opened, you can get notifications almost for free. I was thinking on adding a separate HTTP API to control the load balancer that would read and write to Redis, notifying the load balancer when changes should be applied.

dave_ops 11y ago
But it's a SPoF and an extra remote or local service that has to be configured, maintained, etc. The thing that's coming online has to publish a message to redis anyway, so why not just maintain the service map inside the Rust application and open up a socket that allows those things to speak straight to Nucleon for mutating its configuration?
- michaelmior 11y ago
  That's more what I was getting at, not "heavyweight" in the sense that I see it as a performance concern.
- michaelmior 11y ago
  That's more what I was getting at, not "heavyweight" in the sense that I see it as a performance concern.
halayli 11y ago
What happens if your connection to redis dropped and a pub was made in between?

jedisct1 11y ago

What not NATS instead? There's even a very nice Rust client library for NATS :)