HTTP error 12007

[ertank 30]

Hello,

 

I am using TNetHTTPClient for reading some REST web service data over HTTPS.

Some users have multiple web services to read data from.

Some of these users with multiple web services have frequent checks (check every minute, or even check each 10 seconds).

So they have several times a day below DNS resolution errors showing up in logs.

The application also reach the same web service(s) but different end points from its UI part.

All of these are under exact same domain per web service.

 

Error sending data: (12007) The server name or address could not be resolved

Since the application (thread) read some data from the exact same URL one minute ago, I cannot understand why such errors get logged.

The error also occasionally occurs on the UI part of the application.

 

My web searches all point to the DNS server problems. Users' DNS servers are fine as per my tests. Though, it is not possible to make a test at the error time.

 

I am trying to understand why this error happens where domain was resolved one minute ago (or even 10 seconds ago).

 

Any help is appreciated.

 

Thanks & Regards,

Ertan

[Dave Nottage 613]

1 minute ago, ertank said:

I cannot understand why such errors get logged.

It's because at the time, they had no connection to the internet. I've seen this myself where wifi is not exactly reliable.

[Remy Lebeau 1597]

DNS servers are just servers like any other. And the OS acts as a client like any other. Like any client/server system, servers can go down at times, network routes to servers can go down at times, etc. The Internet doesn't have 100% connectivity 100% of the time. Hiccups happen. All you can do is make sure your software is robust enough to handle network errors when (not if) they happen, retry operations as needed, and move on. 

Edited yesterday at 02:46 PM by Remy Lebeau