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Comment Good Advice Right Here (Score 1) 298

There is a lot of good advice in the other posts, but so many are laden with other people's baggage filling in your missing data. Let me condense it for you to a real solution

I have set up high availability systems that are currently handling 18TB traffic a month, with many millions of page views, with systems that you can literally unplug the server handling the load and have a hiccup of less than a second. And I have done this with 2 servers.

Your 1000 visitors a day is something one server could handle the traffic for, as long as we aren't talking something boutique like streaming live HD video. But that is only half your problem - you want to be able to survive a catastrophie on that machine (someone accidentally kicking the power cord, etc).

First, I would suggest you do not want to handle this hardware yourself. I have worked with ServerBeach and RimuHosting, and would gladly recommend either for this setup. You can handle everything else though.

Second, you want two machines, pretty much anything in ServerBeach's category 3 will handle what you need.

Third, you need them in a particular configuration:

1) You want them each to have a publicly available IP (the references the box), then you want a floating IP between them (that will be the IP your web address uses). More about that IP later.

2) You want the two machines to have a second network card, and have a private network between them. (used for heartbeat and disk replication - see below)

3) you want to set up HALinux and DRBD.

HALinux is a software solution that will run on both boxes. One box is your 'primary' and the other is 'secondary'. The secondary box watches the primary one, and if the primary one fails for any reason, the secondary one takes over for it. It does this by pinging it as often as you specify (perhaps multiple times a second), and if it doesn't answer, it takes over its IP address. You see, that floating IP address I mentioned earlier resolves to the first machine, but the second machine can take it over (for this to work, they have to be on the same router). The downtime here is less than a second.

So that is all well and good, but the second machine needs to be able to run just like the first one. This is where drbd comes in.

DRBD is like Raid mirroring, but for two hard drives in separate machines. Everything written to one hard drive must also be written to the second for the write to be successful. Over a prigate Gig-e network, in my testing, the drives suffer about a 22-25% performance hit. All data - the database, the deployed applications, even the config files for all my services sit on this shared drive. If the first machine fails, the second machine has all the data it needs to take over the job.

I have set up exactly this setup more than once. And despite everyone here laughing at your "1000 users" figure, high availability isn't about scalability - your 1000 users might be worrying about something so important this setup is peanuts to them compared to the lost time if you have to spend 15 minutes jerking around with a server problem. I enjoy working on these systems because I can fix problems outside of a crisis mode, since there is always a machine ready to go.

If you'd like help with this, or if you'd even like someone to set it up and host it for you, I'd be happy to help. (dbock at codesherpas dot com)

Don't spend your money on purchasing 2-6 servers... seriously - look into what 2 decent machines in this setup will cost at ServerBeach, and also think how much easier this will be if they handle all the physical stuff for you. The configuration details are something you can handle yourself, and it is not that hard if you are comfortable at a command line prompt.

Comment Its anti-monopolist (Score 1) 176

This won't be news to the slashdot crowd, but can be a useful thought to stick in someone's head when/if you hear them have that "anti-capitalist" attitude.

"Open source isn't anti-capitalist, it is anti-monopolist, but I can understand how big companies marketing efforts have made it easy to confuse the two. I can show you hundreds upon hundreds of commerical companies from (1-2 person shops to hundreds of employees) making money with open source software, and I can show you conferences and training events that generate millions of dollars of revenue, all based on open-source software. Food is a great analogy - even though recipes are freely available and you can grow your own, restaurants still make a lot of money cooking and serving food. Source code is just a recipe - it does nothing until a professional 'prepares and serves' it for you."

Yes, the analogies are tortured, but can bring someone who believes the first statement closer to the truth. Learn to parrot that back without a religious-sealot-like gleem in your eye, and you can help persuade the world.


Submission + - The Future of Home Networking (

bokmann writes: I just found this article about the future of wireless networking. Besides an interesting overview of the IEEE and where names like 802.11n come from, it talks about some really cool stuff on the horizon, including standards like a wifi cloud around your own computer for peripherals and hardware that could be embedded in everything in your house. From the article, "you could someday use your cell phone to lock all your doors at night".

Comment I did it. (Score 1) 409

Think about the advances in tech and medicine that you have seen in your lifetime. Now think what your kid will see. It might seem like sci-fi, but it is attainable sci-fi. Compared to the cost of having the kid in the first place, or the cost of any lifelong medical treatment that might be prevented, the costs of banking are cheap. I did it for my triplets.

Comment finding the Flaws (Score 1) 520

some people have posted that is it reasonable for someone to be able to audit the source code looking for flaws?

Depending on the language, it would be trivial to use tools like lint, pmd, and findbugs to do some static analysis of the source code. ANY code base that wasn't built with those tools is likely to find a zillion bounds problems, swallwed exceptions, resource allocation problems, and other common boneheaded mistakes. A good developer could apply those tools in less than a day.

they might not find a particular 'smoking gun' problem, but if they find a *bunch* of problems, that would be enough to imply substandard quality and be a factor in the judgement of the case.

If I were a commercial company that built such tools, I would be seeking out this defendant for a chance to use them. Bound to be a huge publicity coup.

Comment Re:Solid-state memories (Score 1) 307

I was just about to add the same thing, with the additional comment that floppy disks as we knew them in 1999 are definitely dead. Between floppies being a thing of the past, the ubiquity of thumb drives fr most portable storage, and solid state hard drives on the market, I think his phrase "Rotating memories are on their way out," is a 100% dead on prediction. He didn't say they would be gone. they are still here, but come on - we can all see the writing on the wall today.

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