shoop slower than scp in optimal bandwidth case

[strangeman]

Hi. I tested shoop on my environment and see that it 5x times slower than scp.

My environment:

Client:

• Core i5 with 8Gb RAM
• Debian 8 with latest updates
• Rust from rustup 0.5.0 (4be1012 2016-07-30)
• libsodium 1.0.0-1 from debian repos
• shoop 0.0.1-prealpha.4

Server:

• Digital Ocean 512Mb droplet
• Debian 8 with latest updates
• Rust from rustup 0.5.0 (4be1012 2016-07-30)
• libsodium 1.0.0-1 from debian repos
• shoop 0.0.1-prealpha.4

Network and test file:

• Broadband connection, speed is around 40Mbit/s.
• Ping and speed to the USA: http://www.speedtest.net/my-result/5546858786
• Test file is a 1GB sample, downloaded from http://www.thinkbroadband.com/download.html

SCP:

strangeman@strangebook:~/tmp$ time scp [email protected]:/root/1GB.zip .
1GB.zip                                                  100% 1024MB   4.1MB/s   04:08    

real    4m12.082s
user    0m7.052s
sys 0m10.004s

SHOOP:

strangeman@strangebook:~/tmp$ time shoop [email protected]:/root/1GB.zip 
downloading ./1GB.zip (1024.0MB)
   1024.0M / 1024.0M (100%) [ avg 0.8 MB/s ]
shooped it all up in 20m48s

real    20m51.508s
user    13m48.492s
sys 7m9.124s

Why? Did shoop optimised only for slow and unstable connections?

[mcginty]

Hey @strangeman! Thanks so much for testing.

If possible, can you build the latest HEAD (remember to do cargo build --release to optimize and get rid of debug info) and let me know if it's still that slow?

There was a memory regression but the fix is in a forked library, so I can't publish a more recent release on crates until the dependency merges the fix.

[mcginty]

Even without that, though, we still need to add multithreading to make the high-speed case actually as high-speed as it wants to be :).

So basically, yeah, it's not currently optimized for the high-speed, high-reliability case, since I'm stuck in a high-ish-speed, low-reliability case :P. You've inspired me to get on the threading business though... I just replicated your test on two VPS's, and it's making me sad.

[strangeman]

Tested with HEAD version. It's faster (~1.5-2MB/s) than old version (~0.8 MB/s), but still slower than scp (~4MB/s).
But HEAD version have another annoying bug: sometimes transmission freezes for 20-30 seconds (looks like server process crashing).

Anyway, this is a great tool! Hope you'll fix these problems in future. :)

[mcginty]

Cool, I think with threading and limiting the progressbar stdout insanity we should be closer to parity on stable connections, which should also be our goal (never regress from TCP).

[mcginty]

Added basic asynchronous file I/O (client side only right now) and de-crazied stdout, and I'm still only seeing ~40Mbps from two 100Mbps VPSs, so there's something more to it. I haven't profiled the server-side yet, so that's next :).

I'm really excited about https://aturon.github.io/blog/2016/08/11/futures/.

Given time, I'm also really interested in a better benching framework for shoop, at the very least to refactor enough where we can have a "virtual" perfect UDT connection and have a solid measure on our real max bandwidth.

[mcginty]

Been making some gradual speed improvements over the last few alpha releases, but there's still a big gap in the case of VPS-VPS transfers where we have low-latency 100Mbps-1Gbps connections. The weird thing is, on occassion, I'm seeing the same transfer speed, but often times it will inexplicably drop from 11MB/s to ~5MB/s, making me wonder if this is perhaps a UDT congestion control thing.

Still more digging to be done.