b203 (u/b203) - Readit News

b203 commented on New Webb image captures clearest view of Neptune’s rings in decades nasa.gov/feature/goddard/... · Posted by u/pseudolus

causi · 3 years ago

JWST's infrared capability is good at showing previously invisible details but I find it very odd its images keep looking like they're lower resolution and less detailed in the visual spectrum than Hubble images. I realize the observation times are shorter but jeez the JWST photo of Jupiter was garbage compared to a telescope that launched 32 years ago.

b203 · 3 years ago

Roughly the angular reolution of a telescope is 1.22*wavelength/diameter. See https://en.wikipedia.org/wiki/Angular_resolution. Hubble uses visual light (0.5 um wavelength) while JWST uses IR (5 um wavelength) and beyond. So the wavelength for JWST is 10x larger than Hibble, but the diameter is only ~2.7X (Hubble 2.4m vs JWST 6.5m dia). So JWST resolution is 1.8x worse than Hubble.

b203 commented on What’s your API’s “Time To 200”? shkspr.mobi/blog/2021/05/... · Posted by u/edent

b203 · 5 years ago

Is it really that important that the time to get to 200 should be small? I understand that it may be frustrating to get started, but assuming I am stuck to this API for a long time, I am lot more worried about stability, quality, performance and availability of the system than time to onboard.

b203 commented on Raft Visualization thesecretlivesofdata.com/... · Posted by u/dedalus

the_arun · 5 years ago

Why RAFT is better? In other words, why do we need a concept of a leader?

b203 · 5 years ago

Basically if you want to replicate data across multiple nodes, all of them need to agree on the sequence of data updates. For example if I did [x=6, x=7], then the outcome of those ops is very different if I did it in the opposite order [x=7, x=6]. Easiest way to do this sequencing is to have a unique leader who will impose the unique order. Strict sequencing is not really serializability, but linearizability. For example, Cassandra doesn't by default have the concept of a leader and hence can't provide linearizability. Of course, there is a problem on how you decide who is the leader and what happens if two nodes think they are the leader at the same time. That's where the genius of Multi-Paxos/Raft comes in. You can read more about sequencing here

https://medium.com/swlh/replication-and-linearizability-in-d...

b203 commented on Raft Visualization thesecretlivesofdata.com/... · Posted by u/dedalus

the_arun · 5 years ago

Why RAFT is better? In other words, why do we need a concept of a leader?

b203 · 5 years ago

Consistent hashing is a routing algorithm, not a consensus algorithm.

https://en.wikipedia.org/wiki/Consistent_hashing

b203 commented on Raft Visualization thesecretlivesofdata.com/... · Posted by u/dedalus

zerr · 5 years ago

What are of the shelve solutions when it comes to actually using these protocols? Implementing these in-house doesn't make sense to me.

b203 · 5 years ago

Zookeeper is the standard one which has been around the oldest. Zookeeper is not based on raft, but it has similar semantics as etcd. So if you don't care about the impl, ZK may be good as well.

b203 commented on IBM is splitting itself into two public companies reuters.com/article/us-ib... · Posted by u/dredmorbius

2bitencryption · 5 years ago

question about the "smaller guys" in cloud (Oracle, IBM):

Do these companies operate their own data centers all over the world to make their cloud offerings work?

"Cloud" is kind of a magical handwavy way to say "don't worry about where the computers are, it will just work." With AWS and Azure I don't worry about where the computers are, because they're all over the world (and even under water, if you follow publicity stunts).

But where are the massive IBM/Oracle/etc data centers? Are they out there, and I just don't know about it?

b203 · 5 years ago

Oracle cloud is quite a thing. It's in 4th place behind AWS, Azure and GCP and has significant presence. For example zoom is a big customer:https://www.lastweekinaws.com/blog/why-zoom-chose-oracle-clo.... I assume under the new tiktok deal, tiktok might run on the Oracle cloud.

b203 commented on Why Your First House Is A Liability medium.com/@introvertmac/... · Posted by u/introvertmac

b203 · 6 years ago

The author's advice is country dependent. My assumption is that he is writing from the perspective of buying in India.

1) In India, rents are very low compared to mortgage payments. 2) Home value appreciation is low given the rate of inflation. 3) financial instruments like home equity line of credit are not available.

So yes, it probably is not a good decision to buy a house in a big city in India. Elsewhere? Do your own calculation.

b203 commented on Amazon Ion amzn.github.io/ion-docs/... · Posted by u/BerislavLopac

willvarfar · 6 years ago

How does this compare to protobuf, thrift, msgpack etc?

It’s roughly the same vintage as protobuf and thrift, from google and Facebook respectively, so perhaps it’s just Amazon’s equivalent, which they just never released as quick as the others did?

Obvious pros and cons, or yet another serialization format with no obvious benefits over anything else?

b203 · 6 years ago

There are some painpoints that are being addressed:

1) timestamp : I have had issues with a round-tripping timestamp representation quite a bit 2) decimal : currency is denoted in decimal rather than float and shows the Amazon retail heritage. This is very useful. 3) symbols : I've had cases where symbol table/dictionary would have made big difference in serialized size

Posted by u/b203 6 years ago

Replication and Linearizability in Distributed Systems medium.com/swlh/replicati...

u/b203

KarmaCake day41June 1, 2020View Original