Initialize rate limit settings

In order to set limits for traffic, you must first understand regular and peak loads in your network. We recommend completing the following steps to benchmark request rates in your environment so that you can implement limits appropriate for your applications.

1. Specify a global rate limit with arbitrary values in the agent configuration file based on the following conditions:

   • Environment where Consul servers are running
   • Number of servers and the projected load
   • Existing metrics expressing requests per second

2. Set the mode to permissive. In the following example, Consul agents are allowed up to 1000 reads and 500 writes per second:

   request_limits { 
       mode = "permissive"
       read_rate = 1000.0
       write_rate =500.0
   }
   

3. Observe the logs and metrics for your application's typical cycle, such as a 24 hour period. Refer to log_file for information about where to retrieve logs. Call the /agent/metrics HTTP API endpoint and check the data for the following metrics:

   • rpc.rate_limit.exceeded with value global/read for label limit_type
   • rpc.rate_limit.exceeded with value global/write for label limit_type

4. If the limits are not reached, set the mode configuration to enforcing. Otherwise adjust and iterate limits.