Am Dienstag, den 13.03.2018, 12:07 +1100 schrieb Daniel Axtens: > > > On Tue, Mar 13, 2018 at 1:43 AM, Balint Reczey <balint.reczey@canonic > al.com> wrote: > > Hi Daniel, > > > > On Mon, Mar 12, 2018 at 2:11 PM, Daniel Axtens > > <daniel.axt...@canonical.com> wrote: > > > Hi, > > > > > > I looked into compression algorithms a bit in a previous role, > > and to be > > > honest I'm quite surprised to see zstd proposed for package > > storage. zstd, > > > according to its own github repo, is "targeting real-time > > compression > > > scenarios". It's not really designed to be run at its maximum > > compression > > > level, it's designed to really quickly compress data coming off > > the wire - > > > things like compressing log files being streamed to a central > > server, or I > > > guess writing random data to btrfs where speed is absolutely an > > issue. > > > > > > Is speed of decompression a big user concern relative to file > > size? I admit > > > that I am biased - as an Australian and with the crummy internet > > that my > > > location entails, I'd save much more time if the file was 6% > > smaller and > > > took 10% longer to decompress than the other way around. > > > > Yes, decompression speed is a big issue in some cases. Please > > consider > > the case of provisioning cluoud/container instances, where after > > booting the image plenty of packages need to be installed and > > saving > > seconds matter a lot. > > > > Zstd format also allows parallel decompression which can make > > package > > installation even quicker in wall-clock time. > > > > Internet connection speed increases by ~50% (according to this [3] > > study which matches my experience) on average per year which is > > more > > than 6% for every two months. > > > > > The future is pretty unevenly distributed, and lots of the planet is > stuck on really bad internet still. > > AFAICT, [3] is anecdotal, rather than a 'study' - it's based on data > from 1 person living in California. This is not really > representative. If we look at the connection speed visualisation from > the Akamai State of the Internet report [4], it shows that lots and > lots of countries - most of the world! - has significantly slower > internet than that person. > > (FWIW, anecdotally, I've never had a residential connection get > faster (except when I moved), which is mostly because the speed of > ADSL is pretty much fixed. Anecdotal reports from users in developing > countries, and rural areas of developed countries are not encouraging > either: [5].) > > Having said that, I'm not unsympathetic to the usecase you outline. I > just am saddened to see the trade-offs fall against the interests of > people with worse access to the internet. If I can find you ways of > saving at least as much time without making the files bigger, would > you be open to that? > > Regards, > Daniel > > [4] https://www.akamai.com/uk/en/about/our-thinking/state-of-the-inte > rnet-report/state-of-the-internet-connectivity-visualization.jsp > [5] https://danluu.com/web-bloat/
I want to mention that you can enable ultra compression levels 20 to 22 in zstd which usually achieve results comparable to the highest compression levels of xz. There should be a level that matches the results of xz -6 while still being faster than it. Best regards, Benjamin -- ubuntu-devel mailing list ubuntu-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel