Service fleet rate adjustment

A method, comprising:

• performing, by individual hosts of a fleet of hosts for a first service:
• updating, in a host table, a host entry to indicate a current heartbeat timestamp for the host;
• retrieving, from a data store, a fleet-wide service rate value for the fleet and a host count value, wherein the fleet-wide service rate value indicates a service rate limit for interactions between the fleet as a whole and a second service, and wherein the host count value indicates a current count of active hosts in the fleet based on host entries in the host table for the fleet;
• determining an individual host rate limit for the host based on the retrieved fleet-wide service rate value and the retrieved host count value, wherein the individual host rate limit indicates a host rate limit for interactions between the host and the second service;
• and
• providing the individual host rate limit to a host rate limiter implemented by the host, wherein the host rate limiter is configured to limit the interactions between the host and second service according to the individual host rate limit.

One or more non-transitory computer-readable storage media storing instructions that, when executed on or across one or more processors, cause the one or more processors to implement an adaptive rate component on individual hosts of a fleet of hosts for a service, the adaptive rate component configured to:

• update, in a host table, a host entry to indicate a current heartbeat timestamp for the host of the fleet of hosts for the service;
• retrieve, from a data store, a fleet-wide service rate value for the fleet and a host count value, wherein the fleet-wide service rate value indicates a service rate limit for interactions between the fleet as a whole and another service, wherein the host count value indicates a current count of active hosts in the fleet based on host entries in the host table for the fleet;
• determine an individual host rate limit for the host based on the retrieved fleet-wide service rate value and the retrieved host count value, wherein the individual host service rate value indicates a host rate limit for interactions between the host and the other service;
• and
• provide the individual host rate limit to a host rate limiter implemented by the host, wherein the host rate limiter is configured to limit the interactions between the host and second service according to the individual host rate limit.