skysight-inc/HackerNews huggingface dataset:
Ask HN: Most cost-effective method of achieving physical redundancy
Hi,

We have a client currently being hosted on a single server in a data centre in the UK. They are asking about getting a level of physical redundancy built into the hosting infrastructure. If a plane lands on the data center, they want to be able to continue operating their website. They are not overly concerned about the service dropping out for a minute or two, but they want to avoid the hours spent offline whilst we restored from backups to another data center and redirected the DNS.

I've done some investigation and found two relatively cheap solutions:

1. Get an additional failover server hosted in another data centre. Operate some level of rsync and mySQL replication to the failover server. Then run a service like http://dynect.com/ to do a rudimentary form of failover via DNS. This is not a 100% solution for everyone (mainly people with badly configured long TTL DNS servers). The rsync/mysql replication is also open to potential problems. This seems like one of the cheapest solutions.

2. Use a provider with a SAN-based virtualisation setup with a backup data centre. I know Hostway offer this, but it is not cheap! In the event of a failover we just fire up our VMWare instance in the failover data center and pick up on the shared SAN.

Both of these are not ideal. 1 is a bit too flakey for my liking, and 2 is a bit too expensive for my client. Is there a neater solution that I am missing?

The application is Java/Struts2/Spring/Hibernate running Tomcat/Apache/MySQL on Linux .

Thanks!
What's your major?
Interesting question :)

1. The most cost effective in terms of immediate capital outlay is active-passive - which is pretty much #1 that you described. This is generally also less effort... and is generally easy to test.

2. The most cost effective long term strategy is active-active as you get ongoing use of both sites. Particularly if the client is happy for reduced performance in a DR scenario... Even if this isn't the case, at least you get a performance boost from the DR site.

This is usually more effort as you need things like replication to work/perform... And you also need to test a whole new range of failure scenarios.

This approach does have some other advantages though. For example, you can do rolling deploys very easily (upgrade DR first, bring down Prod, upgrade Prod).

3. A common hybrid is to have two active sites on the Tomcat/Apache end and active-passive for the MySQL. Depending on the DB load this can be a best of both worlds scenario.

4. Some other solutions use a coherent cache solution - e.g. Tangosol, which works with Hibernate/MySQL. As long as the latency between the two sites is low, then this should work. Tangosol is a non-free product, now owned by Oracle afaik, but I don't think it's prohibitively expensive... I've seen this used a lot, and it's probably a very simple and elegant solution, but I personally don't like adding another moving part in. A lot of people I've met swear by it though, particularly Hibernate users.
Look up Chimp, Soma, slime.vim, fvl, VIlisp, Limp, or Vim-R.

Hacking Vim to send text to a REPL isn't that hard, though it does require some setup.
This is a cool idea--is there something similar for linux? My seven-year-old wants to play, but he's really still learning to read!
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As an aside.. I've been involved in doing the sums on DR-sites in the past and it quite often doesn't add up. So I'd recommend doing a cost-benefit analysis with the client.

You've also got to look at all the intermediate threats. For example, a DR site may be on the same network as the Prod site... Or the client site might be on a single network. So you can spend a lot of money eliminating a sole single point of failure when there are dozens of others around (network failures are much more common than a site getting obliterated).
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This response is exactly why I posted on HN! Love this site.

In terms of active-active, I guess I need two physically disparate load balancers that heart beat with each other? I'm not really a network engineer, and I dont understand what happens to the packets when 1 data center goes down, in terms of routing around it?

Thanks for your time.
If you manage to recreate the physics of the members of The Beatles, a bit should suffice. It might even get you the hordes of screaming teens.
Get your own ASN ;)

You are on the right path with your approach #1. Setup a failover server someplace and keep it sync'd at an interval that is the right balance between too-often and too-stale.

You could opt to get a small dedicated machine from a larger-scale true multi-homed hosting company. Run haproxy on this "small" machine, which serves primarily to redirect traffic to whichever server is currently deemed to be the "active". Basically this is a low-end DIY Akamai kind of solution. Your cost would be somewhere between #1 and #2. You would eliminate the DNS-lag and the issues you can't control (other servers and clients caching stale DNS data that you can't refresh), and you would get most of the benefits of an availability service like Akamai, without the $15KUSD monthly price tag.

There are other benefits to the haproxy solution as well, you can take either machine offline for maintenance with zero (theoretical ;) ) downtime, and if you ever get a traffic surge you can load balance between the two sites (which isn't a bad idea to do all the time if your syncing is up-to-date enough. Send every 10th connection to the fail over site, just to make sure it's always working as expected).
The problem is that my client's client (we are a subcontractor in this instance) is demanding it. I've explained that, in real terms, they will get little benefit from the large capital expenditure, but it's become a contractual requirement.

My current hosting provider are excellent, and we have a > 99.99% uptime with them on this application according to pingdom (and this includes scheduled downtime!) but you know how clients are sometimes!
Search webhostingtalk.com; there are plenty of bad reviews of RS.
I've been fascinated by this question for a while, and my interest has been piqued since hearing the Technology in Journalism session presentation at DjangoCon.

I can think of so many ways that newspapers could monetize their content online, but they really don't seem to get it. Newspapers have tons of great long tail content that can be mined and monetized. They just don't know what is possible and what can be done.
Sometimes the character of a person casts doubt on what they say. Have you never heard the story of the boy who cried wolf?
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What happens if the 'small' server fails?
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Onlinestorelist.com offers a variety of products for apparel, fashion, beauty, health, travel, hotel, wedding, bridal, flower, jewelry and more.
Depends on how risk-averse you are. You can generally get an SLA that would allow you to have a hot-back up of that server, or you take the risk that it won't wail until you can afford the "better" solution.

Doing "high availability" coupled with "low budget" is ALWAYS going to involve some compromises.

If you keep your DNS TTL's low, the worst-case scenario is if the small server fails, you're doing exactly what you would have done anyways: making manual or automated DNS changes.
Dow futures fall as much as technically possible pre-trade. Crash today?
Ok, conceded. (My other point is more important, anyway.)
The income a person earns from their charitable remainder trust is absolutely not tax-free! It's taxed as regular income, for life.

The charity - the final beneficiary - is the one that gets an additional 3.3 million dollars in your example, since the money was put into the trust before capital gains tax - instead of the donor paying tax first, then giving to charity after.
Here's a William Dement protege on polyphasic sleep:

http://www.akbars.net/?p=31

I tend to trust the scientists who have compiled statistics by watching thousands of people sleep under various conditions. And they say that polyphasic sleep is a crock.

Why, then, does this polyphasic thing seem to work for some people? Let me suggest some hypotheses:

* Many people are raised on lack of sleep: Early rising for school, late nights, packed schedules. One can be sleep-deprived for so long that one really has no idea what being fully awake feels like. They say that it can take a month or more of active oversleeping to work your way out of sleep debt. (I'm not sure I have ever been truly out of sleep debt. Just because I know this stuff doesn't mean I'm always good at living by it. ;)

* Chronic sleep deprivation manifests as chronic sleepiness. If you can lie down at any hour of the day and fall asleep within a few minutes, you're sleep-deprived. But it is perhaps more psychologically satisfying to allow yourself to take those periodic naps that your sleepy self craves than to drive yourself through that sleepiness with coffee and determination. Compared to merely being sleep-deprived, being sleep-deprived polyphasically might feel really good.

* Polyphasic sleep is a ritual that requires discipline. The advantage of adopting such a ritual is that it forces you to change your life around (lose your strict 9-to-5 job, stop commuting two hours each way) and encourages you to do things you enjoy (e.g. have a social life). Dare I suggest that it is these side effects, rather than the polyphasic sleep, that make people happy? Dare I go on to suggest that it's better to adopt a different disciplined ritual -- based on, e.g., exercise, diet, or meditation -- that actually lets you get some sleep?

* It may be that a few people really do work better when they sleep polyphasically, or that a few people have associated health or social problems that tend to benefit from a polyphasic schedule. Something tells me, however, that many of these people have not really taken the scientific approach, by adopting the no-sleep-debt schedule for a few months and seeing what the difference is.
You still have a single point of failure with the haproxy though. i.e. if the Data Centre with the proxy is taken out (same probability as the prod site), then the service would stop.

Even if you install multiple haproxies you're either back to the DNS scenario, or a more expensive solution as you were suggesting.

If you are with a large-scale multihomed hosting company, then you might be able to manage with an IP address takeover between sites (ie. the passive haproxy takes over the IP of the master in an event of heartbeat failure). I've not seen this as an offering for the most part though (at smaller outfits anyway).
Cool quote: "3 great forces rule the world - stupidity, fear, and greed."

Now, stupidity (ignorance) is an evil thing, in terms of it is a cause of evil.

Greed, on the other hand, following Mr. Gecko, I would say, is good. "It captures the essence of the evolutionary spirit", and all that.

Fear, can be good or evil, depending on context. Fear of investing in a dot-com with no real revenue is a good thing. Failing to see underlying fudamentals and selling off in a state of panic is a bad thing. Basically fear in terms of preservation of one's assets (or "ass", lol!) is good. Fear based on that other great force, stupidity, is bad.

One could generalize this to say: fear based on the evil force (stupidity) is itself evil, fear based on the good force (greed) is itself good.

I am not a financial analyst but I think my general "two cents" would just be: look at fundamentals - profitability, sector, all those things. If those are good, buy, or at least hold, depending on situation. If they are not, sell. Simple as that. Don't sell from stupid fear. Sell only if rational greed requires it, and then reposition into something safer, like say money markets. :-)
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I have. They generally just forward the complaint on to you and tell you to deal with it. Unless lawyering gets involved, they don't give two hoots.
Oh, and so did NASDAQ and S&P 500 futures. The guy on CNBC just made an earnest "we who are about to die" Gladiator salute (not making this up).
That ignores the context, especially the mood of the user. In a game, you can use the joking/whining/playful messages, the user after all wants to play games and is probably in a playful mood. In the OS UI, that would be a big no, as the tone of the dialog could conflict with the mood of the user, over which you have no control. This could further aggravate the user, who is just trying to get something done.
> In terms of active-active, I guess I need two physically disparate load balancers that heart beat with each other?

Yeah - as the brk indicates in his post, you can use something like haproxy to do this. Afaik, you can get Apache to do this too...

One advantage might be that Apache can be configured to do "sticky sessions" - which you'll need if you're not sync'ing sessions between sites (which in this scenario doesn't seem necessary). Never used haproxy, but it might do this too.

In terms of your active-active setup, you can have two "legs" that are load balanced at the front, or you can have load balancing between each tier. If you're (a) not very experienced or (b) you don't have lots of bandwidth between sites, I'd go with the former and just have load balancing at the front end.
Actually the problems started when equity distribution started. That's what changed some focus of the company away from the clients and on to profit-sharing, benefits, etc.

I let the CFO choose the profit-sharing plan and blindly trusted her choice, until 6 months later my accountant showed me it was giving almost all net profits back to the employees, and had doubled most people's salaries.

So I tried to scale it back, which of course led to huge upset, and endless company-wide meetings and votings and such, which at that point the whole mess had changed the day-to-day focus of the company so much I just felt like shutting it all down and starting something new. But I sold it instead.

Lots of great lessons in what not to do. :-)
If the client is keen to keep costs down... and is amenable to it... then you could give him an alternative URL to use in the case of a catastrophic failure (i.e. your plane scenario).

Then it's up to you if you use two haproxies for active-active or just maintain two active-passive sites.
I just started using Zoho Project. I am fairly impressed with the task dependency, milestones, team integration and such. You can also embed files or edit within with integrated zoho writer, ppt, calendar, alerts.

It is free for one project and unlimited users, paid ones have more space and projects starting at 12$/mo
http://www.thefunded.com/ may have something?
WSJ has oodles of original content.

Also, if you're in finance and you don't read the WSJ, you're not going to be able to communicate with your colleagues.
Wow - I don't think I'd ever heard of "back-testing" before. Google'd it - interesting...

http://en.wikipedia.org/wiki/Backtesting
Oh come on - writing a resume is not that hard! Its two pages max, and while I agree its the most tedious undesirable task in the world, 3 or 4 hours spent on it will sort it once and for all. Then all you have to do is update it every 3 - 6 months for 30 minutes and it will always be ready to use.

Its basically just a bunch of buzz words on the skills you have, and a paragraph about your last few positions/roles.
I was curious also so I ran some numbers:

He's the #1 search result for "personal development", which averages 90,500 searches per month from Google. Assuming he receives 60% of those visits, that's 54,300 visits per month. Since it's search traffic, which would be people willing to click and look for info, he might get a CTR of 2%, which is 1,086 clicks per month. The estimated CPC for that term is $1.92, so that is $2,085 per month, or $25,021 per year.

Since that's a rough estimate of $25k/year for one search term, I think $100,000 per year is reasonable.
Whenever he has a problem that can't be solved by a GUI, he just blogs really, really hard at it until the computer gives up and does whatever he wants out of sheer embarrassment.
To the point about getting your data out. FogBugz On Demand lets you download a snapshot of your database, at any time, in three different formats: MS SQL Server, Access, and MySQL. The FogBugz database schema is open and fully documented here: http://www.fogcreek.com/FogBugz/KB/dbsetup/FogBugzSchema.htm...
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Fix it, fix it, fix it! (apologies to SNL)
Good point, would have liked them to talk about possible ways ameliorate this factor.
Relevance to your question: providing supporting evidence. Citing two specific examples of DoD spending that appear to out of proportion to either need or benefit, but which sent billions to the conglomerates you mention. Both examples based on personal experience.
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I have to laugh. I'm just getting into investing and I put 50% of my net worth in over the last few weeks. Half about a week ago and half yesterday because I figured "Hmm, looks like it is starting to bottom out".

FAIL - I guess this is why they say don't try to call bottoms.

My plan - keep putting money in. I'm young and holding for the long term, this is a great buying opportunity no matter what happens today, or monday, or 6 months from now.

For me specifically, I'm socking a lot of money away in a retirement account to make up for the fact that when I start my company, I won't be making many contributions until I start making money.

Having money working for you even when you are not working helps reduce the risk of starting a company.
MySpace Music expands indie catalogue
A quick question: When replicating mySQL across data centers, is there an easy or perhaps built-in way to encrypt the replication data streams to prevent prying eyes from potentially intercepting the data? If not, might that be a problem if one is passing replicating credit card numbers, etc.?
Do you know what those other 11,615 employees do? I don't, and this is just a stab in the dark, but I'm thinking you're as clueless as I am. I don't know how such an absurd statement gets modded up on a site like HN that tends to be geared for the entrepreneur types.

How exactly would firing 97% of the workforce help turn things around? Let's say you've got 350 writers and a couple great managers. Nevermind what your massive layoffs do for morale or company image. Who is going to publish what they write? Do you stay in the print business or do you take it online? Who prints it? Who is going to distribute it? Who puts it online? Who is going to do the investigation necessary to provide the writers with interesting things to write about? Who is going to market the business? How are you going to process payroll and handle day to day HR issues? Don't you also need a legal department? Afterall, you are writing stories about people and they may not always like what you write. You are going to have the occasional libel suit even if you have covered your bases. Oh, and who is going to run your email servers through which all of this will be organized?

Meet at Starbucks? Sheesh... This is the New York Times. They've been in business since 1851 and have received 98 Pulitzer Prizes. That's more than any other paper. In 1964 they took a case to the Supreme Court (Times v. Sullivan) which further established freedom of the press. In 1971 they successfully argued a Supreme Court case against the US government over a series of articles which revealed the expansion of the Vietnam War at the same time President Johnson was promising not to expand the war. There's no doubt they have some major problems, but this is a very prestigious organization you're talking about- not some crappy startup blog/amateur media outlet.

Your idea solves just about nothing and creates enormous problems. Running a newspaper, or any business for that matter, involves a lot more than you've taken into account.
From my experience - over 95%. Though I grant you that I haven't spent most of my time around typical students.
Why To Start A Startup In A Bad Economy (bullet points)
Excellent use of mimicking! I just don't see how any smartphone that isn't an iPhone or Android phone will survive over the next few years. I believe people have emotional reactions to apps like this. I just wish my iPhone were a bit less annoying, but that's not something people discover until after they buy the phone, so no worries there!
Setting up those kiosks, even in New York City alone, would require a massive capital expenditure; the NYT company doesn't have the cash to spend, and this is not exactly the best time to raise investment for such a project.

And a-la-carte pricing is actually bad for newspaper profits. First of all, if the customer has to look at each headline and think, "do I want to spend another penny for this story?", the customer is likely to pay less. Second, aggregation lets the newspaper profit from people who value different articles at different rates, as Clay Shirky explains (http://www.openp2p.com/pub/a/p2p/2000/12/19/micropayments.ht...):

"Imagine a newspaper sold in three separate sections - news, business, and sports. Now imagine that Curly would pay a nickel to get the news section, a dime for business, and a dime for sports; Moe would pay a dime each for news and business but only a nickel for sports; and Larry would pay a dime, a nickel, and a dime. If the newspaper charges a nickel a section, each man will buy all three sections, for 15 cents. If it prices each section at a dime, each man will opt out of one section, paying a total of 20 cents. If the newspaper aggregates all three sections together, however, Curly, Moe and Larry will all agree to pay 25 cents for the whole, even though they value the parts differently."
Isn't the archive free already?
Initial Thoughts on The G1
Oprah Endorsing Amazon's Kindle
You should spread your risk out with even increments of investments every month for the next 2 years. Since you're young, this is an excellent time to invest because you're definitely getting a bargain in the long run.
In the past, I've used stunnel for encrypting server-to-server communications. It's very easy to setup.
I doubt the bottom will come till next year my friend, so buy incrementally. And I feel the Christmas season will be a fluke of optimism, however the news media may spin in into a the Nightmare Before Christmas... markets are random, probably better off investing in yourself at this point.
Mandelbrot practically said that you shouldn't listen to him; not look to him for answers. But in fact, listening to any opinion on the matter is looking for answers. His point is that nothing will give a correct indication about what is about to happen in our current situation. The classical "markets always correct themselves" doesn't necessarily hold.
The entire time I read this, all I could think about was "squidoo".