Providing API for building applications that have transactions and help with idempotent producing is really exciting. This will help lower a lot of pains associated with building stream processing systems. Doing it with very little performance overhead is amazing.
I do feel that calling it "Exactly-once delivery with kafka" is slightly misleading as this requires the applications to be written in a certain way. The title makes is sound too general and borders on claiming something that is close to impossible. I dont want to be too critical here as the author was very honest with what this means in the blog post. Regardless of the title this is an amazing feature.
> calling it "Exactly-once delivery with kafka" is slightly misleading
Indeed. Idempotent operations is the mainstay of managing "at least once" message delivery. If you had a true "exactly once" system, idempotency would be unnecessary.
> Regardless of the title this is an amazing feature.
I feel it's a good iterative step forward, but nothing near the "revolutionary" that's being boasted.
The reasons this is "currently" impossible are:
- We cannot build communication infrastructures that are 100% reliable
- We build apps that actually crash.
I would not venture as far as to say this is impossible. If one day we are able to leverage quantum entanglement phenomenon in telecommunications network this would certainly be very much possible.
You've been downvoted, but the trick would be to convert asynchronous messaging to synchronous processing that proceeds at a predictable tick. That would make it possible to bypass the FLP result. I'm willing to imagine quantum entanglement could pull this off if we were able to entangle actual transistors. Dunno how plausible that is, but points for creativity if nothing else.
I don't really know a thing about that sort of network, but if you can assume a reliable network, the machine reading the packets going down shouldn't matter. The sender won't get an "ACK", will know the other machine is at fault and not the network, and can resend.
Given a "perfect network" I think exactly-once-delivery is possible, right?
And disks that fail and memory that bitflips and communication methods that are susceptible to random noise and machines dependent on failable power sources.
Yes, that's why I mentioned them. Sorry, if I was not clear, though they also generally have associated fees. So again, nominal breakeven is not the same as actual breakeven.
You do, but that's why dividends are becoming increasingly rare in the stock market. Many firms are preferring buybacks instead, which cause a pop in the stock price for remaining stockholders and so get taxed as capital gains.
I don't believe "dividends are becoming increasingly rare in the stock market". One measure of that is to compare the S&P 500 yield with treasury yield, the latter being near a historic low, but the S&P yield near a consistent 2% for over a decade, and quite attractive now relative to treasuries.
I got the link in an email. Not sure how to link to the email. Anyways the questions are specific to brokerage I dont think it is of any use to anyone other than them.
I think even those who are not worried about their next meal are not going to protest this. India has seen so many terror attacks labeled as intelligence failure that any move to beef up the intelligence infrastructure may even be welcomed. The sad thing is that the probability of this data being misused for political reasons is so much higher in India than in the USA.
In India corruption runs through all levels of government. This is a fact. So, yes, misuse is much more likely.
I understand that you may have wanted to express that it's less likely that the data is abused for political reasons _by the government_ to further certain political goals. This may be true, I don't know.
Given the volatility you may doubt the longevity of bitcoin as a currency, but since you can exchange it for some goods and services it looks like Real Money to me (at least right now).
If we get down to the basics I think anything that is a medium of exchange is a currency. So in some circles cigarettes and Tide work as currency. Though these "currencies" are not legal tender.
Money is a store of value, a medium of exchange, and a unit of account.
A store of value is something you could accept in payment for work and hold on to.
A medium of exchange is something a shoemaker can use to obtain bread from a baker who doesn't want shoes.
A unit of account is something with a value stable enough that you can measure the value of arbitrary goods with it; like the Bloomberg article says, it's what enables a cheesemaker to put a price tag on cheese without forcing her to become a currency speculator.
Bitcoins slipped into speculative realm a couple of weeks ago and probably after the crash the speculators will exit the market. A stable bitcoin can easily serve the three functions you listed above. As I said in my first comment this volatility raises questions about longvity of bitcoins but they have not ceased to be real money, at least for now.
It is just a 3-4 year old technology lets wait and watch how this plays out before writing it off completely.
I dont know if bitcoins will ever stabilize or go down to zero but I also believe that no one can be so sure about how a free market is going to behave to just write it off at this moment.
The words "free market" are not a talisman that dispels common sense. Currencies are fundamentally backed by trust. Trust in the US Dollar is based on the status quo (the Nash equilibria of our adoption of the currency, &c), the degree to which our interests are aligned with those of the government (not 100%, not 0%) and the basic economics of taxation that is dollar denominated, a gigantic federal payroll that is dollar denominated, and the fact that the federal government --- the world's largest buyer of everything --- conducts all its business in dollars.
Bitcoin has none of this; it appears to substitute the moral equivalent of a Yahoo stock message board.
I think the volume/unit time during the crash is generally higher than during the bubble phase. This can be seen in the steeper slope of price-time graph during declining phase compared to the rising phase of most bubbles. I guess fear is a quicker call to action than greed in financial markets.
