Refactored to allow offline experimentation, and ended up changing the
allowedvariation (aka fudge factor) to 3. 10 seems too high, and 1.5 too low.
Scale earlier, so even if the first chunk takes less than the configured
time period, allowance is made that later chunks might transfer slower.
Decided to use the same allowedvariation to decide when to start
scaling.
Smoothed the scaling out.
Some examples:
ghci> upscale (BwRate 10 (Duration 60)) 25
BwRate 13 (Duration {durationSeconds = 75})
-- A small scaling upwards after 1/3rd the time. Not noticable.
ghci> upscale (BwRate 10 (Duration 60)) 60
BwRate 30 (Duration {durationSeconds = 180})
-- At the configured time, 3x scaling.
ghci> upscale (BwRate 10 (Duration 60)) 120
BwRate 60 (Duration {durationSeconds = 360})
-- A typical upscaling, here a 1 minute duration became 6 minutes
-- due to the first chunk taking 2 minutes to transfer.
ghci> upscale (BwRate 10 (Duration 60)) 600
BwRate 300 (Duration {durationSeconds = 1800})
-- Here the first chunk took 10 minutes to transfer, so it will
-- take 30 minutes to detect a stall.
Sponsored-by: Dartmouth College's DANDI project
Improve annex.stalldetection to handle remotes that update progress less
frequently than the configured time period.
In particular, this makes remotes that don't report progress but are
chunked work when transferring a single chunk takes longer than the
specified time period.
Any remotes that just have very low update granulatity would also be
handled by this.
The change to Remote.Helper.Chunked avoids an extra progress update when
resuming an interrupted upload. In that case, the code saw first Nothing
and then Just the already transferred number of bytes, which defeated this
new heuristic. This change will mean that, when resuming an interrupted
upload to a chunked remote that does not do its own progress reporting, the
progress display does not start out displaying the amount sent so far,
until after the first chunk is sent. This behavior change does not seem
like a major problem.
About the scalefudgefactor, it seems reasonable to expect subsequent chunks
to take no more than 1.5 times as long as the first chunk to transfer.
Could set it to 1, but then any chunk taking a little longer would be
treated as a stall. 2 also seems a likely value. Even 10 might be fine?
Sponsored-by: Dartmouth College's DANDI project
Added annex.bwlimit and remote.name.annex-bwlimit config that works for git
remotes and many but not all special remotes.
This nearly works, at least for a git remote on the same disk. With it set
to 100kb/1s, the meter displays an actual bandwidth of 128 kb/s, with
occasional spikes to 160 kb/s. So it needs to delay just a bit longer...
I'm unsure why.
However, at the beginning a lot of data flows before it determines the
right bandwidth limit. A granularity of less than 1s would probably improve
that.
And, I don't know yet if it makes sense to have it be 100ks/1s rather than
100kb/s. Is there a situation where the user would want a larger
granularity? Does granulatity need to be configurable at all? I only used that
format for the config really in order to reuse an existing parser.
This can't support for external special remotes, or for ones that
themselves shell out to an external command. (Well, it could, but it
would involve pausing and resuming the child process tree, which seems
very hard to implement and very strange besides.) There could also be some
built-in special remotes that it still doesn't work for, due to them not
having a progress meter whose displays blocks the bandwidth using thread.
But I don't think there are actually any that run a separate thread for
downloads than the thread that displays the progress meter.
Sponsored-by: Graham Spencer on Patreon
When annex.stalldetection is not enabled, and a likely stall is detected,
display a suggestion to enable it.
Note that the progress meter display is not taken down when displaying
the message, so it will display like this:
0% 8 B 0 B/s
Transfer seems to have stalled. To handle stalling transfers, configure annex.stalldetection
0% 10 B 0 B/s
Although of course if it's really stalled, it will never update
again after the message. Taking down the progress meter and starting
a new one doesn't seem too necessary given how unusual this is,
also this does help show the state it was at when it stalled.
Use of uninterruptibleCancel here is ok, the thread it's canceling
only does STM transactions and sleeps. The annex thread that gets
forked off is separate to avoid it being canceled, so that it
can be joined back at the end.
A module cycle required moving from dupState the precaching of the
remote list. Doing it at startConcurrency should cover all the cases
where the remote list is used in concurrent actions.
This commit was sponsored by Kevin Mueller on Patreon.
annex.stalldetection can now be set to "true" to make git-annex do
automatic stall detection when it detects a remote is updating its transfer
progress consistently enough.
This commit was sponsored by Luke Shumaker on Patreon.
