Randomly slow download/upload speeds on MicroOS servers (US-EAST)

[henrikperssonvermiculus]

Hi,

We’ve been experiencing intermittent slow download and upload speeds on our MicroOS servers (running in the Hetzner US-EAST location), particularly when downloading static files from GitHub or Adoptium (e.g., while installing Java).

The issue is random — sometimes 1 in 5 or 1 in 10 attempts. Speeds drop from ~155 MB/s to as low as 100 KB/s.

This affects both HTTPS downloads and file transfers over SCP. We haven’t made any major changes on our end. Has anyone else seen similar behavior?

I’ve tried adjusting both the MTU and TCP buffer sizes, but the issue remains. I’m starting to wonder if there may be underlying network or hardware issues in the US-EAST location?

We use same snapshots and server type in the EU region but haven't have any of those issues yet.

From TCP connection statistics (via ss -ti), I see a lot of retransmissions and out-of-order packets. For example:

rcv_ooopack: 7694
delivery_rate: 631 kbps

Example connection:

ESTAB      0      0      178.156.154.240:41900     185.199.109.133:https
	 cubic wscale:9,9 rto:220 rtt:19/5.093 ato:40 mss:1448 pmtu:1500 rcvmss:1444 advmss:1448 cwnd:10
	 bytes_sent:1126 bytes_acked:1127 bytes_received:59623244 segs_out:27923 segs_in:36927
	 data_segs_out:3 data_segs_in:36923 send: 6.1 Mbps delivery_rate: 631 kbps
	 rcv_ooopack: 7694 minrtt:18.355

Any insight or similar observations would be appreciated!

Regards,
Henrik