Envoy is an open-source edge and service proxy designed for cloud-native applications. It acts as a communication bus and universal data plane designed for large microservice architectures. Envoy is often used for service discovery, load balancing, and observability, making it a critical component in modern infrastructure.
When working with Envoy, you might encounter the error message 'Cluster Not Found'. This typically manifests when Envoy attempts to route traffic to a cluster that is not recognized or defined in its configuration. The error can disrupt service routing and lead to failed requests.
The 'Cluster Not Found' error occurs when Envoy cannot find a cluster definition matching the name specified in the route configuration. Clusters in Envoy are collections of endpoints that Envoy can route traffic to. If a cluster is not defined, Envoy cannot route traffic, resulting in this error.
The root cause of this issue is typically a missing or incorrectly defined cluster in the Envoy configuration file. This can happen due to typos, misconfigurations, or incomplete configuration updates.
To resolve this issue, follow these steps:
Ensure that the cluster is correctly defined in the Envoy configuration file. Check for typos or missing entries. The configuration should include the cluster name, type, and endpoints. For example:
{
"clusters": [
{
"name": "my_service_cluster",
"connect_timeout": "0.25s",
"type": "STRICT_DNS",
"lb_policy": "ROUND_ROBIN",
"load_assignment": {
"cluster_name": "my_service_cluster",
"endpoints": [
{
"lb_endpoints": [
{
"endpoint": {
"address": {
"socket_address": {
"address": "127.0.0.1",
"port_value": 8080
}
}
}
}
]
}
]
}
}
]
}
Ensure that the route configuration references the correct cluster name. The cluster name in the route configuration must match exactly with the name defined in the cluster configuration.
Use Envoy's configuration validation tool to check for errors in your configuration file. Run the following command:
envoy --mode validate -c /path/to/envoy.yaml
This command will validate the configuration and report any errors.
After making changes, reload the Envoy configuration to apply updates. This can typically be done by sending a SIGHUP signal to the Envoy process:
kill -SIGHUP $(pgrep envoy)
(Perfect for DevOps & SREs)
(Perfect for DevOps & SREs)
