Re: ostree - how to enable libcurl's continue/resume feature

[Jonathan Lebon <jlebon redhat com>]

On Tue, Dec 22, 2020 at 7:34 PM Davis Roman via ostree-list
<ostree-list gnome org> wrote:
> https://curl.se/libcurl/c/CURLOPT_LOW_SPEED_TIME.html
> (It contains the time in number seconds that the transfer speed should be below the CURLOPT_LOW_SPEED_LIMIT 
> for the library to consider it too slow and abort.)
>
> https://curl.se/libcurl/c/CURLOPT_LOW_SPEED_LIMIT.html
> (It contains the average transfer speed in bytes per second that the transfer should be below during 
> CURLOPT_LOW_SPEED_TIME seconds for libcurl to consider it to be too slow and abort.)
>
> Do you think this is a reasonable path to consider? If not, does anything else come to mind?

AFAIU from reading the libcurl docs, the default for these knobs is "disabled":
https://curl.se/libcurl/c/CURLOPT_LOW_SPEED_TIME.html
https://curl.se/libcurl/c/CURLOPT_LOW_SPEED_LIMIT.html

And libostree no longer sets those values (see
https://github.com/ostreedev/ostree/pull/1349), so the defaults should
be active. (And I'm assuming you're using a libostree that has that
patch.)

> Another approach that we're taking is trying to figure out why 'ostree pull' fails in the first place due 
> to our very sluggish data connection.

What's the exact error from libcurl that gets thrown? Depending on the
error, it may be reasonable to have a knob in libostree to catch that
and retry (resuming from what was downloaded so far).