起个新帖讨论讨论DNS - 未名空间MITBBS历史存档

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起个新帖讨论讨论DNS

起个新帖讨论讨论DNS# EmergingNetworking - 热门网络技术

c*e2009-04-14 07:04

1 楼

上次打电话给移民医生
告诉我说初了一项
其他都可以在family dr 那儿做然后把结果给拿去那样的话就收85
其他地方都是170-180左右
可是今天去family dr那儿做了TB test
因为移民dr和family dr在一个楼里，我就想去问问我的育苗要打什么！
那位前台的大妈开口就是要我叫押金还是100多美金，也不告诉我任何信息。
我就问她一共要多少钱！她马上变成了300多
我当时气坏了这些人怎么前后说得都不一致呀？
来这儿问问大家都花了多少！就怕找了其他的移民医生开始也就和我要170左右然后
去他们那儿做又给开始加钱！
还有到底要打些什么育苗呀？我现在在给孩子的哺乳期间，family dr建议我还是小心
点，最好不要打。如果可以不打我就现在不想打！

v*n2009-04-14 07:04

2 楼

DNS sucks应该没人反对吧?
papers倒是不少，能解决问题好像没多少。大家啥想法？展开说说。

s*g2009-04-14 07:04

3 楼

You need to be more specific. DNS sucks in what way? what problem are you
trying to solve? People are using DNS every second, it can not be that bad.

v*n2009-04-14 07:04

4 楼

the way how the name is resolved. on one hand, if your local DNS can
cache everything, it is just a RTT. normally we can't. so there may be
multiple RTTs.
plus, if a record is changed, updating all the interested parties would
be a nightmare.
also, if nodes are on the move, the name/addr mapping could be changed
relatively often.

you
bad.

【在 s*****g 的大作中提到】

: You need to be more specific. DNS sucks in what way? what problem are you
: trying to solve? People are using DNS every second, it can not be that bad.

z*r2009-04-14 07:04

5 楼

what is a better way to maintain such a vast database?

【在 v**n 的大作中提到】

: the way how the name is resolved. on one hand, if your local DNS can
: cache everything, it is just a RTT. normally we can't. so there may be
: multiple RTTs.
: plus, if a record is changed, updating all the interested parties would
: be a nightmare.
: also, if nodes are on the move, the name/addr mapping could be changed
: relatively often.
:
: you
: bad.

s*g2009-04-14 07:04

6 楼

The vast database needs to be distributed, no question about it. The problem
is the efficiency of new record propagation and existing record querying.
Current model to achieve this is pretty much ad hoc in application level.
If we can figure out a way to design a DNS system such that queries/propagations can be routed/summarized like IP has,that would drastically increase the scalability,
robustness, efficiency of the system. We can do L2 routing already, doing L7
routing is not totally out of q

z*r2009-04-14 07:04

7 楼

跟俺昨天想到的几乎一样，后来自己给否了。原因是IP是二进制，长度也固定，非常容
易structural。而domain name长度不固定，如果都按照最大长度来，真正有效部分（
假设也有类似net mask的东西）还是没有本质区别。到最后，还是到了.com等root，跟
现在的似乎没有区别。
俺看现在的cache这种就挺好，需要改进的是dns server之间如何更有效率的刷新
database，说到底还是application level。当然这个东西绝对可以放到网络设备上，
其实很多公司也有相应的产品，比如cisco, f5等，但还是跑在linux上和普通的dns
server没有本质区别

problem
propagations can be routed/summarized like IP has,that would drastically
increase the scalability,
L7
generation DNS system, do not leave this task only to application developers.

【在 s*****g 的大作中提到】

: The vast database needs to be distributed, no question about it. The problem
: is the efficiency of new record propagation and existing record querying.
: Current model to achieve this is pretty much ad hoc in application level.
: If we can figure out a way to design a DNS system such that queries/propagations can be routed/summarized like IP has,that would drastically increase the scalability,
: robustness, efficiency of the system. We can do L2 routing already, doing L7
: routing is not totally out of q

v*n2009-04-14 07:04

8 楼

老大，能不能请教一下csco和f5的那种产品可以对DNS有所提高？最近突然对DNS有兴趣
了。

drastically

【在 z**r 的大作中提到】

: 跟俺昨天想到的几乎一样，后来自己给否了。原因是IP是二进制，长度也固定，非常容
: 易structural。而domain name长度不固定，如果都按照最大长度来，真正有效部分（
: 假设也有类似net mask的东西）还是没有本质区别。到最后，还是到了.com等root，跟
: 现在的似乎没有区别。
: 俺看现在的cache这种就挺好，需要改进的是dns server之间如何更有效率的刷新
: database，说到底还是application level。当然这个东西绝对可以放到网络设备上，
: 其实很多公司也有相应的产品，比如cisco, f5等，但还是跑在linux上和普通的dns
: server没有本质区别
:
: problem

z*r2009-04-14 07:04

9 楼

算法提高估计不一定，主要是implementation方面。还是属于load balancer的概念？
看看cisco ACE或者f5 big-ip之类？

【在 v**n 的大作中提到】

: 老大，能不能请教一下csco和f5的那种产品可以对DNS有所提高？最近突然对DNS有兴趣
: 了。
:
: drastically