### Understand the alert

This alert is triggered when the number of failed RPC (Remote Procedure Call) requests made by the Consul server in a datacenter surpasses a specific threshold. Consul is a service mesh solution and is responsible for discovering, configuring, and segmenting services in distributed systems.

### What are RPC requests?

Remote Procedure Call (RPC) is a protocol that allows one computer to execute remote procedures (subroutines) on another computer. In the context of Consul, clients make RPC requests to servers to obtain information about the service configurations or to execute actions.

### What does it mean when RPC requests fail?

When Consul's client RPC requests fail, it means that there is an issue in the communication between the Consul client and the server. It could be due to various reasons like network issues, incorrect configurations, high server load, or even software bugs.

### Troubleshoot the alert

1. Verify the connectivity between Consul clients and servers.

   Check the network connections between the Consul client and the server. Ensure that the required ports are open and the network is functioning correctly. You can use tools like `ping`, `traceroute`, and `telnet` to verify connectivity.

2. Check Consul server logs.

   Analyze the Consul server's logs to look for any error messages or unusual patterns related to RPC requests. Server logs can be found in the default Consul log directory, usually `/var/log/consul`.

3. Review Consul client and server configurations.

   Ensure that Consul client and server configurations are correct and in accordance with the best practices. You can find more information about Consul's configuration recommendations [here](https://learn.hashicorp.com/tutorials/consul/reference-architecture?in=consul/production-deploy).

4. Monitor server load and resources.

   High server load or resource constraints can cause RPC request failures. Monitor your Consul servers' CPU, memory, and disk usage. If you find any resource bottlenecks, consider adjusting the server's resource allocation or scaling your Consul servers horizontally.

5. Update Consul to the latest version.

   Software bugs can lead to RPC request failures. Ensure that your Consul clients and servers are running the latest version of Consul. Check the [Consul releases page](https://github.com/hashicorp/consul/releases) for the latest version.

### Useful resources

1. [Consul official documentation](https://www.consul.io/docs)
2. [Consul Reference Architecture](https://learn.hashicorp.com/tutorials/consul/reference-architecture?in=consul/production-deploy)
3. [Troubleshooting Consul guide](https://developer.hashicorp.com/consul/tutorials/datacenter-operations/troubleshooting)
