Slow Download Speeds from AWS S3

[Steven Hartland]

Window scaling and receive buffer scaling is the most likely cause.

Check what the sysctl net.inet.tcp.recvspace is set to, then try 
increasing it e.g.
sysctl net.inet.tcp.recvspace=655360

This jumped the transfer rate with a wget and your test URL from 3MB/s 
to 30MB/s here.

     Regards
     Steve

On 16/02/2017 14:34, Sydney Meyer via freebsd-net wrote:
> Hello,
>
> I'm seeing continuous slow download speeds from Amazon S3, but only on FreeBSD. Other OSes saturate the connection without problems.
>
> This happens with 10.3-RELEASE and 11.0-RELEASE and only with AWS S3 in different regions (Ireland, London, Frankfurt, US Standard have been tested) whilst using fetch, curl, et. al.
>
> I have tested this on multiple machines, bare metal, bhyve, Xen and VMware VMs, routed setups and direct pppoe links.. all the same.
>
> Anyone seeing similar issues?
>
> Here's a url to try:
>
> http://s3.eu-central-1.amazonaws.com/4f48caf1d8bcbef8/c5b38f8b3625d2b6/zerofile.raw
>
> Also, when doing double NAT, i.e. VMware Fusion FreeBSD Guest with "Share with my Mac"-Interface, the machine is doing completely fine, as in saturates the link, 90Mbps otherwise between 12-15Mbps..
>
> I also switched the FreeBSD Routers with Linux-based ones and with the isp-provided router box, with the same result.
>
> I have launched VMs with Digital Ocean to "rule out" my ISP and there seems to be the same issue. Downloading from S3 is multiple times slower than any other connection to services outside of S3 or on any other OS.
>
> It seems like other people are seeing the same issue:
>
> https://forums.freebsd.org/threads/59756/#post-343064
> _______________________________________________
> freebsd-net at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-net
> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"