The article mentions that "Tokyo" DC was taken offline by disconnecting the data center from the "New York" and "Paris" DCs. Then writes were performed, Tokyo was reconnected, and the writes replayed, effectively re-syncing the DCs.
My question is: how was consistency maintained? What mechanism prevented the same record from being changed both in Tokyo and in New York while the network was split? Or, what mechanism resolved the conflicts? I think the article might be glossing over some details here. I'm guessing that either one side of the split was offline (or at least read-only) during the outage or that the writes were made without guarantees.
Cassandra allows you to specify the consistency of writes and reads per operation, so for these operations, it would be required to trade consistency for availability.
Conflict resolution is done using timestamps on each column. At first, this might seem too crude to work, but works well in production on real world applications.
When the datacenter link was healed, one of the 3 mechanisms used to repair consistency kicked in and data was restored to a consistent state: Hinted Handoff, Anti-Entropy, and Read Repair.
Why is it that people will hold against you an immature act that you did years ago, ignoring the fact that people tend to mature as they age?
Perhaps the timeline will help overcome this tendency. By making everyone's history more visible, maybe people will become less sensitive to seeing past examples of immaturity and therefore weigh them less when making judgements about a person.
First, even if natrius cannot answer your question, absence of a counter-example does not constitute proof of your argument. Second, I've been taking an ADD medication called Dexadrine for about 10 years now, and in my opinion the effect on me has not diminished.
I am not an expert, but when i read the other posts about Adderall(which is similar to Dexadrine afaik) it seems not problem free.
The article suggests Methylphenidate does not have positive long term implications, but here in Germany for example Dexadrine is not available as treatment for ADD. So you suggesting we have not access to the effective medication.
Just curious, did you stop it sometimes to check the difference? I was also diagnosed with ADD, but only took Ritalin over a short time when i was a kid.
I don't know how similar/dissimilar Dexadrine and Adderall are, but they have really different effects on me. Adderall made me feel high, and seemed to encourage me to focus like a laser beam on low-level details. Dexadrine, on the other hand, has a very subtle effect on me. I've never felt high when taking it. It's more like a gradual transition into being able to focus at will. When it wears off I can no longer focus easily. On weekends I usually take half the usual dosage, and sometimes I skip taking it all together. When I skip it, aside from difficulty paying attention/focusing, I have mild withdrawal symptoms like feeling tired, headache and an increased appetite.
Having said all this, I want to point out that my doctor told me that different medications work for different people. I may just be lucky enough to have the right body chemistry for a drug like Dexadrine to work well for me.
The site guidelines ( http://ycombinator.com/newsguidelines.html ) say "On-Topic: Anything that good hackers would find interesting." Judging by the comments on this thread, such is the case here.
I was diagnosed with ADHD at age 18. At that point in my life I had developed pretty much a hatred for school, and had resolved to never go to college. Spending 8 hours/day at school was akin to torture for me. I found it to be mind-numbingly boring.
My doctor had me try various medications. Adderall was too intense. It got me high and gave me a tendency to focus too much on the wrong level of a problem (I would obsess over details). Worse, my body acclimated and I found that I needed a higher and higher dosage to have the same "benefit".
Everything turned around for me when I found out about a different medication from a friend - Dexadrine. My doctor never mentioned it to me but once I asked him about it he agreed to let me try it. Boy am I glad he did. To make a long story short, I finally went to college, graduated at the top of my class, then went on to Stanford to earn an advanced degree. Now I have a job that I love.
I've been on this medication for almost 10 years. I never acclimated to it (in the sense of needing a higher dosage for the same effect) and the side effects are very mild (slight loss of appetite, slightly harder to sleep).
Recently I decreased the dosage by almost 50%. I've found that over the years I've somehow learned how to concentrate better, and that therefore my need for the med has decreased. This makes me think that my brain has somehow changed for the better. Perhaps all the concentrating I did while on a higher dosage served as practice and that the benefits from all this practicing apply even without the medication. Maybe some day I'll be able to get off of it completely. But for now I still have a tough time concentrating without it.
There's a sad real-world example of people who are willing to shorten their lives in order to earn more money: the sulphur miners of East Java ( http://www.bbc.co.uk/news/world-asia-pacific-12301421 ). The motivations are a bit different in this case - the miners are doing this to be in a little less poverty - but the net effect I think is to make things a bit harder for the people who choose to take lower-paying jobs and not to put their lives at such risk (since the miners who have more money presumably get first dibs on available food to purchase).
It sounds like you have to be wearing the device in order to benefit from it. Do you work from home while "plugged in"? Or, can you just use it while thinking about a tough problem or while learning something new and then when it's turned off still have the insights/new knowledge you gained?
ChristianMarks said in one of his comments that he believes the device has allowed him to overcome a bias in the valley against hiring older engineers. Why would he want to reveal the details of a device that if widely used could erode his advantage?
At first I wasn't going to mention this (lest it become the reason he doesn't share the details), but then I realized, here's a smart guy who has a device that makes him even smarter, so I figure he probably already knows. :)
What if Curebit had an important demo/presentation that was botched as a result of this? I think the response should be tailored to provide them with a learning opportunity rather than to hurt their startup. A private naming/shaming like betageek suggested would probably do the trick.
My question is: how was consistency maintained? What mechanism prevented the same record from being changed both in Tokyo and in New York while the network was split? Or, what mechanism resolved the conflicts? I think the article might be glossing over some details here. I'm guessing that either one side of the split was offline (or at least read-only) during the outage or that the writes were made without guarantees.