Incorrect description for aws.applicationelb.request_count: metric DOES include HTTP 460

[dabd]

Bug

aws.applicationelb.request_count description says:

"Not inclusive of HTTP 460, HTTP 400, and some kinds of HTTP 503 and 500."

The HTTP 460 exclusion claim appears incorrect.

AWS docs deduction

From CloudWatch ALB metrics:

• RequestCount: "only incremented for requests where the load balancer node was able to choose a target"
• HTTPCode_ELB_4XX_Count: "These requests were not received by the target, other than in the case where the load balancer returns an HTTP 460 error code."

460 means the client closed after the ALB routed to a target. A target was chosen. The AWS definition implies it counts in RequestCount.

Empirical confirmation

Over 24 hours on a production ALB:

request_count = target_2xx + target_3xx + target_4xx + target_5xx + httpcode_elb_4xx + httpcode_elb_5xx
142,652       = 141,535    + 0          + 1,108      + 0          + 9               + 0