When the front end sends a request, how can the front end determine the DNS parsing error?

when the frontend sends a request, how can the frontend judge an DNS parsing error or a connection timeout error?

Apr.01,2021

think too much. The DNS parsing process comes before the page parses. no, no, no. The front end cannot get this information.
if it is the request interface, there is no corresponding HTTP status code tag parsing error. If so, it can be judged.

Why does the front end judge this? There should be no need to deal with this situation


the front end can only handle data in the http layer

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b37d72-2c0ae.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b37d72-2c0ae.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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