Download
Browse source Changelog
Documentation
Project   Bug Bounty   Help us   Known bugs   TODO Protocols   CA bundle   HTTP Cookies   HTTP/2   SSL Certs Releases   Security   Version numbers   Vulnerabilities curl tool   man page   Tutorial   HTTP scripting Who and Why
libcurl
ABI API Competitors Examples Features Mailing list Related libs Using libcurl Tutorial Testimonials
Get Help
curl-library curl-users Mailing lists Book: Everything curl Video presentations Report a bug Paid support
Development
Autobuilds Code Style Contribute Deprecate Internals Release Notes Release Procedure Roadmap Run Tests Security Process Specifications Test curl
News
Changelog Release table
curl / Mailing Lists / curl-users / Single Mail
Buy commercial curl support from WolfSSL. We help you work out your issues, debug your libcurl applications, use the API, port to new platforms, add new features and more. With a team lead by the curl founder himself.

Regarding async DNS resolver

From: Amit via curl-users <curl-users_at_cool.haxx.se>
Date: Fri, 12 Jul 2019 07:05:43 +0530

>
>
> Hi All,
>

   Can someone please confirm if it is fine to notify DNS resolved status
from CURL to clients ?
   Please see below mail for more details.

   Thanks and Regards,
   Amit Katyal

>
> ---------- Forwarded message ----------
> From: Amit <itsamitkatyal_at_gmail.com>
> To: curl-users_at_cool.haxx.se
> Cc:
> Bcc:
> Date: Tue, 9 Jul 2019 09:15:40 +0530
> Subject: Regarding async DNS resolver
> Hi All,
>
> This is regarding performance issue due to usage of async DNS resolver for
> MULTI interface in lib CURL.
>
> My application is using lib CURL (7.57 version) Muti interface with async
> DNS resolver enabled (I.e CURLRES_ASYNCH and POSIX_THREADED are defined).
> But I am facing an performance issues as there is no mechanism in CURL to
> notify DNS resolved status back to client application due to which HTTP
> request (after DNS resolution) are going out of the box with delay.
>
> The reason for the delay is that application is having an timer
> implementation which wakes up every 1 second and requests CURL to check all
> the ongoing requests (I.e. by calling curl_multi_perform()). So even if DNS
> was resolved within 100 msec, request will only be sent out after 1 second
> (I.e. with delay of 900 msec).
>
> I could see that in CURL release (7.59) a callback has been added to
> notify the clients about DNS resolution start status, but this will not
> help as I am looking for some trigger to notify about DNS resolution.
>
> I would like to seek your opinion/thoughts if it is good idea to implement
> a callback to notify the clients about DNS resolution ?. Also, let me know
> if there is any other available mechanism to achieve the same functionality.
>
> Thanks & Regards,
> Amit Katyal
>
> _______________________________________________
> curl-users mailing list
> curl-users_at_cool.haxx.se
> https://cool.haxx.se/cgi-bin/mailman/listinfo/curl-users
>

-----------------------------------------------------------
Unsubscribe: https://cool.haxx.se/list/listinfo/curl-users
Etiquette: https://curl.haxx.se/mail/etiquette.html
Received on 2019-07-12