I’ve been experiencing sluggish performance with Fastly hosted sites recently. It seems that I am often being routed to the Seattle (BFI) POP, despite being located in the midwest US.
An example using Reddit’s image server, which is hosted by Fastly and is very noticeable when it starts slowing down and images/videos load slowly:
> i.redd.it
Server: dnsr1.sbcglobal.net
Address: 68.94.156.1
Non-authoritative answer:
Name: dualstack.reddit.map.fastly.net
Addresses: 2a04:4e42:5::396
151.101.21.140
The resolved IPs are associated with the Seattle/BFI POP:
Details: cache-bfi-krnt7300107-BFI (151.101.21.140)
Details: cache-bfi-krnt7300116-BFI (2a04:4e42:5::396)
A traceroute confirms this, and also shows excessively high latency once reaching Fastly’s network, which could indicate congestion here.
11 63 ms 65 ms 63 ms sea-b1-link.ip.twelve99.net [62.115.132.155]
12 55 ms 55 ms 56 ms fastly-ic-370623.ip.twelve99-cust.net [213.248.90.123]
13 108 ms 109 ms 107 ms 151.101.21.140
Tweaking my DNS configuration can get me routed to closer POPs, but even this isn’t always better. Another example using NextDNS:
Name: dualstack.reddit.map.fastly.net
Addresses: 2a04:4e42:52::396
199.232.73.140
This time I’m routed to Kansas City (MCI), which is closer and has lower ping:
11 26 ms 26 ms 27 ms kanc-b2-link.ip.twelve99.net [62.115.139.125]
12 25 ms 25 ms 24 ms fastly-ic-375497.ip.twelve99-cust.net [62.115.8.215]
13 26 ms 26 ms 26 ms 199.232.73.140
But it still experiences periods of sluggish performance. This was tested using fastly-debug.com on 8/26 around 9 PM CDT:
Note the low bandwidth and high retransmits.
Is there anything that can be done to improve this performance? My ISP is AT&T and the source network is 99.41.244.0/22.