xds-server

xDS gRPC server implementation for control planes.

This crate provides the gRPC server layer for xDS:

• [XdsServer] - Main server type wrapping all xDS services
• [XdsServerBuilder] - Builder for configuring the server
• State-of-the-World (SotW) protocol support
• Delta xDS protocol support (incremental updates)
• Health checking via gRPC health protocol
• Prometheus metrics for observability
• Graceful shutdown with connection draining
• Connection tracking and limits

Example

use xds_server::XdsServerBuilder;
use xds_cache::ShardedCache;
use std::sync::Arc;

# async fn run() -> Result<(), Box<dyn std::error::Error>> {
let cache = Arc::new(ShardedCache::new());
let server = XdsServerBuilder::new()
    .cache(cache)
    .enable_sotw()
    .enable_delta()
    .enable_health_check()
    .enable_metrics()
    .build()?;

// Use with tonic - includes health and metrics
server.serve("[::]:18000".parse()?).await?;
# Ok(())
# }

Production Features

Health Checking

The server implements the gRPC health checking protocol:

# use xds_server::XdsServerBuilder;
# use xds_cache::ShardedCache;
# use std::sync::Arc;
# fn example() -> Result<(), Box<dyn std::error::Error>> {
# let cache = Arc::new(ShardedCache::new());
let _server = XdsServerBuilder::new()
    .cache(cache)
    .enable_health_check()
    .build()?;

// Health status is managed automatically
// Available at grpc.health.v1.Health/Check
# Ok(()) }

Metrics

Prometheus metrics are exposed for monitoring:

# use xds_server::XdsServerBuilder;
# use xds_cache::ShardedCache;
# use std::sync::Arc;
# fn example() -> Result<(), Box<dyn std::error::Error>> {
# let cache = Arc::new(ShardedCache::new());
let _server = XdsServerBuilder::new()
    .cache(cache)
    .enable_metrics()
    .build()?;
# Ok(()) }

Graceful Shutdown

The server supports graceful shutdown with connection draining:

# use xds_server::XdsServerBuilder;
# use xds_cache::ShardedCache;
# use std::sync::Arc;
use std::time::Duration;

# fn example() -> Result<(), Box<dyn std::error::Error>> {
# let cache = Arc::new(ShardedCache::new());
let _server = XdsServerBuilder::new()
    .cache(cache)
    .graceful_shutdown(Duration::from_secs(30))
    .build()?;

// Server will drain connections on SIGTERM/SIGINT
# Ok(()) }