AWS Route 53如何实现基于延迟的路由? [英] How does AWS Route 53 achieve latency based routing?

问题描述

AWS Route 53可以提供基于延迟的路由策略(请参阅来自AWS Route 53的延迟路由策略.

AWS Route 53 can provide latency based routing policy (see latency routing policy from AWS Route 53.

但是我想知道Route 53如何准确知道我的笔记本电脑(客户端)和服务器端点之间的延迟.

But I am wondering how Route 53 knows the latency between my laptop (client) and the server endpoint accurately.

AWS是否发布了提供此功能的机制?我应该以100％的信任度相信它还是仅仅基于最佳猜测?

Did AWS publish it's mechanism to provide this feature? Should I trust it with 100% faith or it simply a best-guess based?

推荐答案

一旦您发送了DNS查询，为时已晚，服务无法尝试对您进行三角剖分"，并实际测量延迟到你.那不是那样.

Once you're sending a DNS query, it's too late for the service to try to "triangulate" you, as it were, and actually measure the latency to you. That isn't what happens.

根本无法找到"you"，因为查询Route 53的不是"you"，而是DNS递归解析器，通常由您的ISP或由递归DNS提供商(例如Google(8.8).8.8)或OpenDNS.

It's also impractical to locate "you" at all, because it's not "you" that's querying Route 53 -- it's your DNS recursive resolver, usually operated by your ISP or a resolver provided by a recursive DNS provider like Google (8.8.8.8) or OpenDNS.

Route 53 支持edns-client-subnet扩展，其中解析器(还必须支持它才能使此部分正常工作)转发IP地址的掩码版本，以便权威服务器(路由53)拥有大约(但不完全是)您的地址.例如，如果您的IP地址为203.0.113.20，则解析程序将发送类似于203.0.xxx.xxx的信息(过于简化，但这是个主意-相邻IP地址很可能在地理位置上接近).该信息用于提供最佳响应.如果您的解析器不支持EDNS，则使用解析器的位置，而不是可能更精确地截断IP地址的表示形式.

Route 53 supports the edns-client-subnet extension, where the resolver (which must also support it for this part to work) forwards a masked version of your IP address, so that the authoritative server (Route 53) has approximately, but not exactly, your address. If for example, your IP address were 203.0.113.20, the resolver would send something resembling 203.0.xxx.xxx (an oversimplification, but that's the idea -- adjacent IP addresses, more likely than not, will be geographically proximate). This information is used to come up with an optimal response. If your resolver doesn't support EDNS, the location of the resolver is used, instead of the potentially more accurate truncated representation of your IP address.

就像所有基于IP的地理位置一样，这也不是一门精确的科学-最好的猜测是基于Route 53维护的地理位置数据库中的查询，该查询是针对全球IP地址空间以及与每个区块最接近的AWS区域地址-在物理上不一定要在很大的圆周或空中距离上最接近，而是根据互联网上最有可能通过的路由的拓扑来最接近.

Like all IP-based geolocation, this is not an exact science -- it's a best guess, based on a lookup from a geolocation database that Route 53 maintains, of the global IP address space and the closest AWS region to each block of addresses -- not necessarily physically closest in great circle or air-line distance, but closest based on the topology of the most likely routes for traffic to take, on the Internet.

他们是如何建立该数据库的?当然，那部分没有记录.

How did they build that database? That part isn't documented, of course.

这篇关于AWS Route 53如何实现基于延迟的路由?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！