这不还是dns服务器不可用的时候强制失败

This is not a forced failure when the DNS server is unavailable

??? if DNS if fails, we have error other than emptyResponse, so the connection will not made. what is the problem?

被你们整晕了，总之查询失败就是失败，不要管是不是 emptyResponse，然后 force-query 与否有不同的逻辑

@patterniha 你看下当前代码的逻辑是否符合 #4949 (comment) ，不符合的话我删掉最新的 commit，你重新 PR

被你们整晕了，总之查询失败就是失败，不要管是不是 emptyResponse，然后 force-query 与否有不同的逻辑

@patterniha 你看下当前代码的逻辑是否符合 #4949 (comment) ，不符合的话我删掉最新的 commit，你重新 PR

现在这样是没 force query 的话 错误是emptyresponse 连接成功 不然强制失败 以及只缓存 emptyresponse

@Fangliding 那我把这个 commit 删了，你 PR 修一下吧

@RPRX

let explain:

A: ech DNS query fails, get no response
B: ech DNS query is successful, and receiving response is successful, but no ech-record found.
C: ech DNS query is successful, and ech-record received.

S1: if C, connection is made with ech-TLS.
S2: if A, connection is not made.
S3: if B, if echForceQuery is true, connection is not made, otherwise connection is made with plain-SNI, also we cache emptyRecord for 5 minutes.

@RPRX

this is my logic, because ech may be used in MitM-uses, what is your logic?

please say your logic and I implemented that.

我觉得mitm继续用分片就是了 没必要硬用ech

@Fangliding @RPRX

can you please say your logic exactly?

I think we can reach an agreement with three mode echForceQuery.

but I still doesn't know your exact logic.

@patterniha 我们的意思是把 AB 视为同一种情况，然后走 S3 的逻辑

but suppose our internet is dropped for just a seconds, so we get no response and we cache this fail for 5 minutes !!!

and we don't try to use ech-TLS, or getting new key for 5 minutes !!!

this is not help for my MitM-use and if fragment blocked, this cause connection fail for 5 minutes.

///

@RPRX

so I implement three mode echForceQuery:

full: -> equal to current true
half: -> equal to current false
none: -> equal to your logic for false.

is it OK?

echForceQuery 这样吧：

• "none": 非强制，懒查询，默认值（非必须查到，任何失败都是五分钟后再尝试；对于 emptyResponse，也是等五分钟）
• "half": 非强制，积极查询（非必须查到，但每次尝试，不用等五分钟；对于 emptyResponse，等五分钟）
• "full": 强制，故积极查询（必须查到，否则不连接；对于 emptyResponse，下次重新查）

对于 "none" 和 "half"，第一次等查询，后面不等查询（但这次查到了会带 TTL 缓存，下次就能用），避免影响体验

OK, please wait...

ok, i only subdivide that for showing errors.

还有对于 "none" 和 "half"，第一次可以等查询，后面就别等了（不知道现在是不是这个逻辑）

其实更简单的逻辑是如果 echForceQuery 填 false 就每次都尝试查询，但除了第一次，可以先建立连接