Dmitry Tantsur a9d82bb12b Enable parallel downloads and allow tuning concurrency
Currently we set parallel_image_downloads to False, which means that
all downloads that go through the image cache are serialized.
This change enables it by default and deprecates in favour of a new
more fine-grained mechanism: the new option image_download_concurrency
specifies how many downloads (and raw conversions) will run in parallel.

Update logging to trace how long each download takes.

Change-Id: I8b85afda295029f85e82143cf7d4bcb2316860f6
2021-09-09 06:00:30 +00:00
..
2020-03-31 13:40:00 +00:00
2017-03-02 13:48:18 +02:00