Log in

No account? Create an account
Linux Virtual Server - brad's life — LiveJournal [entries|archive|friends|userinfo]
Brad Fitzpatrick

[ website | bradfitz.com ]
[ userinfo | livejournal userinfo ]
[ archive | journal archive ]

Linux Virtual Server [Jun. 4th, 2001|02:44 pm]
Brad Fitzpatrick
Been reading up on the LVS project ... it's a lot more mature than it was last time I checked. I'll have to continue reading after Friday.

I should study.

[User Picture]From: foobar
2001-06-04 07:02 pm (UTC)

Re: LJ

Dorkus, huh? Telling blow.

Feeling a little defensive there?

Actually from what I've seen and experienced, Cisco's WD and F5's 3DNS are rather weak. They don't suck, but they only go so far.

See, the key to _those_ products is that you don't use them for everything. They're one piece of the puzzle. Cisco and F5 wouldn't try to deny it. DNS is a great step to do some stuff with, and can be useful for, say, distributing servers around - but I've yet to hear anyone claim it's a powerful load balancing service, until you, of course. I've seen tiny little sites use it, but I've never heard or seen any site that actually does any respectable amount of traffic use dns as a load balancing solution, because it's just not good enough.

So why not just post the hack to lj_dev or something instead of sending it to Brad privately? Maybe you could teach us something. I'm curious to see just what you do, maybe you really do know how to work some magic. I'm always up for learning new techniques, but I've got no problem with saying that I'm more than a little skeptical that it's as wonderful as you seem to be making it out to be.
(Reply) (Parent) (Thread)
[User Picture]From: bradfitz
2001-06-04 07:15 pm (UTC)

Re: LJ

He's talking about wide area load balancing, btw... not load balancing like BIG/ip, backhand, LVS, etc.
(Reply) (Parent) (Thread)
[User Picture]From: foobar
2001-06-04 07:27 pm (UTC)

Re: LJ

I know, which is why I said "distributing servers around". DNS hacks are great for that, but he was saying it was a mistake buying the Big/IP instead of using his DNS "hack", which means he apparently thinks that distributed dns hacks are a replacement for local server load-balancing, which is silly at best.

So, he's either:

a.) an absolute genius for being able to make DNS do something no one else has ever been able to make it do, as far as I know,
b.) being difficult,
c.) misinformed and confused, or
d.) an idiot.

Let's just say I have doubts about a.

I'm just tired of the constant bitching people are doing. Constructive criticism is fine, I like that. Random bashing is just stupid. If his system is really good, great - use it, and I'd love to see what he does so I can learn something. But if he's just huffing and puffing in an attempt to make himself look cool, which he appears to be doing, I see no problem with cutting his legs out from under him, he's asking for it. If he's not, well, he's welcome to cut my legs out from under me. :)
(Reply) (Parent) (Thread)
[User Picture]From: bradfitz
2001-06-04 07:31 pm (UTC)

Re: LJ

Several months ago when LJ was on one server he gave me access to a server at a colo place of his and said, "go ahead and use it".

However, I had no use for it then because LJ's infrastructure wasn't ready for it.

I think what he's saying is that had I started putting LJ servers all over the country already (and did the DNS hack), then I wouldn't have had to buy the BIG/ip because I'd have 10 servers all over the country instead of in one room, and then DNS would work well, since people are spread out well.

At least that's my best guess.

He does know his stuff, though.
(Reply) (Parent) (Thread)
[User Picture]From: ekashp
2001-06-04 07:42 pm (UTC)

Local v Wide Area DNS Ballancing

Thanks Brad, and yes, you very much got the point.

It can actualy do some cool stuff even in the local area environment as well. It starts to have scaling problems over 12 servers or so, limitation of UDP packets.

I always have leaned towards free tools ...

(Reply) (Parent) (Thread)
[User Picture]From: dormando
2001-06-04 07:46 pm (UTC)

Re: Local v Wide Area DNS Ballancing

Ever hear of mod_backhand? It's free, and can load balance evenly across machines with widely different speeds, and uses a UDP-based information protocol.

Err, also... Can DNS round-robin give us control over our systems like the transparent paid members server we have?
(Reply) (Parent) (Thread)
[User Picture]From: ekashp
2001-06-04 07:47 pm (UTC)

Leg ?

There are those who say the letter 'a' is the correct choice, some of them have worked for InterNIC, and the US Govt.

I wasn't bitching, realy.

We now return you to your local programing.

Brad - maybe I'll just mail you in private next time, or call you at your mom's house again ...
(Reply) (Parent) (Thread)
[User Picture]From: bradfitz
2001-06-04 08:00 pm (UTC)

Re: Leg ?

You only caught me there that one time because I happened to be visiting. I live in Seattle... they live in Portland.
(Reply) (Parent) (Thread)
[User Picture]From: ekashp
2001-06-04 08:06 pm (UTC)


Ya, I know. Congrats on the house, the view is beauty.
Sorry about your bike. And Kenji's ass !
(Reply) (Parent) (Thread)
[User Picture]From: ekashp
2001-06-04 07:36 pm (UTC)

Re: LJ

Us old men get ornery now and then. Maybe you'd care to surf by my resume or press page at <href="http://www.kashpureff.org/">Kashpureff.org</a>. I've been 'round the block on the 'net a few times, and do get a little offended when folks who might have little clue come off as if I don't have one either. (or that I don't own an ISP - What was that all about ? Was just trying to offer Brad some co-lo. )

Yes, Cisco WW Director and 3DNS are pretty sucky, for what they charge you for sure. The third big player in the market is Resonate, I rate their local and wide area products highly.

Readers Digest Version of DNS load ballancing:
(it's not realy a hack at all...)

Given three servers, make all three authoritative for the desired name. On each server, only answer with that servers IP for an A record. Use short TTLs.

To understand how well this does work, consider the nature of UDP packets going to servers in diverse locations with servers under various loads. Yes, it does basicaly what Director and 3DNS do, with the exception of session persistance.

I read what I wrote earlier, and have to question you as to just how wonderful did I make it out to be ? It'll do a job.
No, it isn't a be-all solution, nor as you point out are the other solutions. It's a part of the puzzle. So is the option of using LVS clusters...
(Reply) (Parent) (Thread)
[User Picture]From: foobar
2001-06-04 07:53 pm (UTC)

Re: LJ

Oh, I wasn't saying that you don't own an ISP. I was amazed that someone who has the money to buy an ISP would be so cheap as to try to avoid load balancers. Then again, most small ISPs don't actually host sites that do any noticeable traffic. Yours might be an exception, I don't know enough about it, as I've never heard of it before.

Yes, yes, I'm familiar with resonate too. Nice resume, looks rather like mine. :P It's nicely put together, though, I will say that. As far as experience, I don't really see anything on there that you've done that I haven't.

So how is that "hack" anything special? I've seen that in use before, and it's great, but let's rewind a bit, shall we?

"Except Brad just went and bought a crappy
load balancer - when I had already told him
how to do it with DNS last XMas already... "

Hmmm, sounds to me like you're saying that distributed data centers are a replacement for load balancing. See, the problem I have is when people try to act like they're smarter than other people by mocking their decisions and even worse, do it by making stupid comments.

If it's part of the puzzle, it's not a replacement for a different piece. You can't build a car by replacing the wheels with another bumper. Slap as many as you want on there, and while it might make a decent sled on snow, it's not gonna make much of a car.

Building a solid distributed environment takes a lot more than knowing how to set up DNS. I never claimed distributing servers was a replacement for a load balancer - you did.

If you had simply offered your "dns hack" as something to add to - not replace - the current load balancing setup, I never would have questioned you. You stuck that foot in your mouth, not me, don't blame me for pointing it out.
(Reply) (Parent) (Thread)