Re: DNS data not refreshed after CURLOPT_DNS_CACHE_TIMEOUT

On Sun, 30 Aug 2020, Narasimha M wrote:

> Is there a way to force the name resolution/DNS checking periodically.

You can for example close your handle and crete a new one, so that the
connection won't survive.

> In my particular case, I would like to keep a single connection and check
> for updates on the server using that connection forever.

If you want to reuse the connection, why would you bother to resolve the name
over and over? It's pointless then!

> Could you please explain when CURLOPT_DNS_CACHE_TIMEOUT is used?

When libcurl wants to resolve a host name it checks if the address is already
present in its DNS cache, where it will be stored and used for up to
CURLOPT_DNS_CACHE_TIMEOUT seconds.

> If the connection lives for more than this time and if the time between
> performs is more than this time, resolution would be done.

Not at all. If there's an existing connection present already, there's no need
to resolve the name.

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