Reeder is making excessive requests to RSS feeds all at one time

Resolved

A client with a Reeder user agent appears to be making a notable amount of requests to our servers all at the same time, many of which are repetitive and extraneous, causing unnecessary usage and allocation of resources.

The behavior reflects the same qualities of a DDoS attack. However, it can't be classified as such, since we have no reason to believe intentions are malicious. But the issue causes a degradation in the performance of RSS feeds for its users.

Furthermore, the user agents appear to be slightly different among the many requests, which looks to be intentional to circumvent our rate limits and IP detection. See user agent examples of most recent logs below:

Reeder/5040002 CFNetwork/1410.0.3 Darwin/22.6.0Reeder/4020.89.01 CFNetwork/1126 Darwin/19.5.0
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.1.2 Safari/605.1.15 Reeder/5.4
Reeder/5040002 CFNetwork/1490.0.4 Darwin/23.2.0
Reeder/5020205 CFNetwork/1335.5 Darwin/21.6.0
Reeder/5040002 CFNetwork/1492.0.1 Darwin/23.3.0
Reeder/5040104 CFNetwork/1335.5 Darwin/21.6.0
Reeder/5040002 CFNetwork/1335.5 Darwin/21.6.0
Reeder/5030102 CFNetwork/1406.0.4 Darwin/22.4.0
Reeder/5020205 CFNetwork/1492.0.1 Darwin/23.3.0
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2.1 Safari/605.1.15 Reeder/5.4
Reeder/5040104 CFNetwork/1490.0.4 Darwin/23.2.0
Reeder/4020.89.01 CFNetwork/1490.0.4 Darwin/23.2.0
Reeder/4020.89.01 CFNetwork/1410.1 Darwin/22.6.0
Reeder/4020.89.01 CFNetwork/1410.0.3 Darwin/22.6.0
Reeder/5040002 CFNetwork/1240.0.4.5 Darwin/20.6.0
Reeder/3.2.40 CFNetwork/1335.0.3.4 Darwin/21.6.0
Reeder/4020.89.01 CFNetwork/1335.0.3.4 Darwin/21.6.0
Reeder/5040103 CFNetwork/1335.5 Darwin/21.6.0
Reeder/5040002 CFNetwork/1474 Darwin/23.0.0
Reeder/5020205 CFNetwork/1474.1 Darwin/23.0.0
Reeder/5040002 CFNetwork/1458.2.2 Darwin/23.0.0
Reeder/5040002 CFNetwork/1474.1 Darwin/23.0.0
Reeder/5040002 CFNetwork/1485 Darwin/23.1.0
Reeder/5020205 CFNetwork/1490.0.4 Darwin/23.2.0
Reeder/3.2.40 CFNetwork/1126 Darwin/19.5.0