Files
khadhroony-bobobot/kb_lib/src/http_pool.rs
2026-04-22 16:01:19 +02:00

616 lines
24 KiB
Rust

// file: kb_lib/src/http_pool.rs
//! HTTP endpoint pool and routing.
//!
//! This module provides a lightweight endpoint pool on top of `HttpClient`.
//! It is responsible for:
//! - filtering endpoints by role
//! - skipping paused or disabled endpoints
//! - simple round-robin selection among active endpoints
//! - preferring endpoints with available concurrency slots
/// Snapshot of one pooled HTTP endpoint.
#[derive(Clone, Debug, serde::Serialize)]
#[serde(rename_all = "camelCase")]
pub struct KbHttpPoolClientSnapshot {
/// Logical endpoint name.
pub endpoint_name: std::string::String,
/// Provider name.
pub provider: std::string::String,
/// Resolved endpoint URL.
pub endpoint_url: std::string::String,
/// Supported roles.
pub roles: std::vec::Vec<std::string::String>,
/// Current endpoint status string.
pub status: std::string::String,
/// Remaining pause duration in milliseconds when paused.
pub paused_remaining_ms: std::option::Option<u64>,
/// Available concurrency slots.
pub available_concurrency_slots: usize,
}
/// Pool of HTTP endpoints.
#[derive(Clone, Debug)]
pub struct HttpEndpointPool {
clients: std::vec::Vec<crate::HttpClient>,
next_index: std::sync::Arc<std::sync::atomic::AtomicUsize>,
}
impl HttpEndpointPool {
/// Creates a pool from already constructed clients.
pub fn new(clients: std::vec::Vec<crate::HttpClient>) -> Result<Self, crate::KbError> {
if clients.is_empty() {
return Err(crate::KbError::Config(
"http endpoint pool requires at least one client".to_string(),
));
}
Ok(Self {
clients,
next_index: std::sync::Arc::new(std::sync::atomic::AtomicUsize::new(0)),
})
}
/// Creates a pool from endpoint configurations.
pub fn from_endpoint_configs(
endpoint_configs: std::vec::Vec<crate::KbHttpEndpointConfig>,
) -> Result<Self, crate::KbError> {
let mut clients = std::vec::Vec::new();
for endpoint in endpoint_configs {
if !endpoint.enabled {
continue;
}
let client_result = crate::HttpClient::new(endpoint);
let client = match client_result {
Ok(client) => client,
Err(error) => return Err(error),
};
clients.push(client);
}
Self::new(clients)
}
/// Creates a pool from the global configuration.
pub fn from_config(config: &crate::KbConfig) -> Result<Self, crate::KbError> {
Self::from_endpoint_configs(config.solana.http_endpoints.clone())
}
/// Returns the number of pooled clients.
pub fn len(&self) -> usize {
self.clients.len()
}
/// Returns whether the pool is empty.
pub fn is_empty(&self) -> bool {
self.clients.is_empty()
}
/// Returns a live snapshot of pooled endpoints.
pub async fn snapshot(&self) -> std::vec::Vec<KbHttpPoolClientSnapshot> {
let mut snapshots = std::vec::Vec::new();
for client in &self.clients {
let status = client.endpoint_status().await;
let (status_text, paused_remaining_ms) = match status {
crate::KbHttpEndpointStatus::Active => ("Active".to_string(), None),
crate::KbHttpEndpointStatus::Disabled => ("Disabled".to_string(), None),
crate::KbHttpEndpointStatus::Paused { remaining_ms } => {
("Paused".to_string(), Some(remaining_ms))
}
};
snapshots.push(KbHttpPoolClientSnapshot {
endpoint_name: client.endpoint_name().to_string(),
provider: client.endpoint_config().provider.clone(),
endpoint_url: client.endpoint_url().to_string(),
roles: client.endpoint_config().roles.clone(),
status: status_text,
paused_remaining_ms,
available_concurrency_slots: client.available_concurrency_slots(),
});
}
snapshots
}
/// Selects one client for a role and method.
pub async fn select_client_for_role_and_method(
&self,
required_role: &str,
method: &str,
) -> Result<crate::HttpClient, crate::KbError> {
let method_class = crate::HttpClient::classify_method(method);
let _ = method_class;
let mut active_indices = std::vec::Vec::new();
let mut paused_count = 0usize;
let mut disabled_count = 0usize;
let mut role_mismatch_count = 0usize;
let client_count = self.clients.len();
let mut index = 0usize;
while index < client_count {
let client = &self.clients[index];
if !client.supports_role(required_role) {
role_mismatch_count += 1;
index += 1;
continue;
}
let status = client.endpoint_status().await;
match status {
crate::KbHttpEndpointStatus::Active => {
active_indices.push(index);
}
crate::KbHttpEndpointStatus::Paused { .. } => {
paused_count += 1;
}
crate::KbHttpEndpointStatus::Disabled => {
disabled_count += 1;
}
}
index += 1;
}
if active_indices.is_empty() {
return Err(crate::KbError::Http(format!(
"no active http endpoint available for role '{}' and method '{}': paused={}, disabled={}, role_mismatch={}",
required_role, method, paused_count, disabled_count, role_mismatch_count
)));
}
let rotation_seed = self
.next_index
.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
let active_len = active_indices.len();
let mut offset = 0usize;
while offset < active_len {
let active_index = active_indices[(rotation_seed + offset) % active_len];
let client = &self.clients[active_index];
if client.available_concurrency_slots() > 0 {
return Ok(client.clone());
}
offset += 1;
}
let fallback_index = active_indices[rotation_seed % active_len];
Ok(self.clients[fallback_index].clone())
}
/// Executes one raw JSON-RPC request through the pool.
pub async fn execute_json_rpc_result_raw_for_role(
&self,
required_role: &str,
method: std::string::String,
params: std::vec::Vec<serde_json::Value>,
) -> Result<serde_json::Value, crate::KbError> {
let client_result = self
.select_client_for_role_and_method(required_role, &method)
.await;
let client = match client_result {
Ok(client) => client,
Err(error) => return Err(error),
};
client.execute_json_rpc_result_raw(method, params).await
}
/// Executes one typed JSON-RPC request through the pool.
pub async fn execute_json_rpc_request_typed_for_role<T>(
&self,
required_role: &str,
method: std::string::String,
params: std::vec::Vec<serde_json::Value>,
) -> Result<T, crate::KbError>
where
T: serde::de::DeserializeOwned,
{
let client_result = self
.select_client_for_role_and_method(required_role, &method)
.await;
let client = match client_result {
Ok(client) => client,
Err(error) => return Err(error),
};
client
.execute_json_rpc_request_typed::<T>(method, params)
.await
}
/// Executes `getHealth` through the pool.
pub async fn get_health_for_role(
&self,
required_role: &str,
) -> Result<std::string::String, crate::KbError> {
self.execute_json_rpc_request_typed_for_role::<std::string::String>(
required_role,
"getHealth".to_string(),
std::vec::Vec::new(),
)
.await
}
/// Executes `getSlot` through the pool.
pub async fn get_slot_for_role(
&self,
required_role: &str,
config: std::option::Option<solana_rpc_client_api::config::RpcContextConfig>,
) -> Result<u64, crate::KbError> {
let config_value_result =
kb_pool_serialize_optional_json_value(config, "pool getSlot config");
let config_value = match config_value_result {
Ok(config_value) => config_value,
Err(error) => return Err(error),
};
let params = kb_pool_build_optional_config_only_params(config_value);
self.execute_json_rpc_request_typed_for_role::<u64>(
required_role,
"getSlot".to_string(),
params,
)
.await
}
/// Executes `sendTransaction` through the pool.
pub async fn send_transaction_for_role(
&self,
required_role: &str,
encoded_transaction: std::string::String,
config: std::option::Option<solana_rpc_client_api::config::RpcSendTransactionConfig>,
) -> Result<std::string::String, crate::KbError> {
let config_value_result =
kb_pool_serialize_optional_json_value(config, "pool sendTransaction config");
let config_value = match config_value_result {
Ok(config_value) => config_value,
Err(error) => return Err(error),
};
let params =
kb_pool_build_first_string_optional_config_params(encoded_transaction, config_value);
self.execute_json_rpc_request_typed_for_role::<std::string::String>(
required_role,
"sendTransaction".to_string(),
params,
)
.await
}
}
fn kb_pool_build_optional_config_only_params(
config: std::option::Option<serde_json::Value>,
) -> std::vec::Vec<serde_json::Value> {
let mut params = std::vec::Vec::new();
if let Some(config) = config {
params.push(config);
}
params
}
fn kb_pool_build_first_string_optional_config_params(
first: std::string::String,
config: std::option::Option<serde_json::Value>,
) -> std::vec::Vec<serde_json::Value> {
let mut params = vec![serde_json::Value::String(first)];
if let Some(config) = config {
params.push(config);
}
params
}
fn kb_pool_serialize_optional_json_value<T>(
value: std::option::Option<T>,
label: &str,
) -> Result<std::option::Option<serde_json::Value>, crate::KbError>
where
T: serde::Serialize,
{
match value {
Some(value) => {
let value_result = serde_json::to_value(value);
match value_result {
Ok(value) => Ok(Some(value)),
Err(error) => Err(crate::KbError::Json(format!(
"cannot serialize {}: {error}",
label
))),
}
}
None => Ok(None),
}
}
#[cfg(test)]
mod tests {
use tokio::io::AsyncReadExt;
use tokio::io::AsyncWriteExt;
#[derive(Debug)]
struct TestHttpServer {
url: std::string::String,
shutdown_tx: std::option::Option<tokio::sync::oneshot::Sender<()>>,
}
impl TestHttpServer {
async fn spawn(server_name: std::string::String) -> Self {
let listener = tokio::net::TcpListener::bind("127.0.0.1:0")
.await
.expect("listener bind must succeed");
let local_addr = listener.local_addr().expect("local addr must exist");
let (shutdown_tx, mut shutdown_rx) = tokio::sync::oneshot::channel::<()>();
let server_name_for_task = server_name.clone();
tokio::spawn(async move {
loop {
tokio::select! {
_ = &mut shutdown_rx => {
break;
},
accept_result = listener.accept() => {
let (mut stream, _peer_addr) = accept_result.expect("accept must succeed");
let local_server_name = server_name_for_task.clone();
tokio::spawn(async move {
let mut buffer = vec![0u8; 65536];
let read_result = stream.read(&mut buffer).await;
let bytes_read = read_result.expect("read must succeed");
let request_text =
std::string::String::from_utf8_lossy(&buffer[..bytes_read]).to_string();
let split_result: std::vec::Vec<&str> =
request_text.split("\r\n\r\n").collect();
let body = if split_result.len() >= 2 {
split_result[1].to_string()
} else {
std::string::String::new()
};
let request_json: serde_json::Value =
serde_json::from_str(&body).expect("request body must be valid json");
let method = request_json["method"]
.as_str()
.expect("method must be a string")
.to_string();
let id = request_json["id"].clone();
let response_body = if method == "getHealth" {
serde_json::json!({
"jsonrpc": "2.0",
"result": format!("ok-{}", local_server_name),
"id": id
}).to_string()
} else if method == "getSlot" {
let slot_value = if local_server_name == "server_a" {
111u64
} else {
222u64
};
serde_json::json!({
"jsonrpc": "2.0",
"result": slot_value,
"id": id
}).to_string()
} else if method == "sendTransaction" {
serde_json::json!({
"jsonrpc": "2.0",
"result": format!("sig-{}", local_server_name),
"id": id
}).to_string()
} else {
serde_json::json!({
"jsonrpc": "2.0",
"error": {
"code": -32601,
"message": "Method not found"
},
"id": id
}).to_string()
};
let response_text = format!(
"HTTP/1.1 200 OK\r\nContent-Type: application/json\r\nContent-Length: {}\r\nConnection: close\r\n\r\n{}",
response_body.len(),
response_body
);
let _ = stream.write_all(response_text.as_bytes()).await;
let _ = stream.shutdown().await;
});
}
}
}
});
Self {
url: format!("http://{}", local_addr),
shutdown_tx: Some(shutdown_tx),
}
}
async fn shutdown(mut self) {
if let Some(shutdown_tx) = self.shutdown_tx.take() {
let _ = shutdown_tx.send(());
}
}
}
fn make_http_endpoint(
name: &str,
provider: &str,
url: std::string::String,
roles: std::vec::Vec<std::string::String>,
) -> crate::KbHttpEndpointConfig {
crate::KbHttpEndpointConfig {
name: name.to_string(),
enabled: true,
provider: provider.to_string(),
url,
api_key_env_var: None,
roles,
requests_per_second: 20,
burst_capacity: 5,
send_transaction_requests_per_second: Some(2),
send_transaction_burst_capacity: Some(1),
heavy_requests_per_second: Some(1),
heavy_burst_capacity: Some(1),
connect_timeout_ms: 2000,
request_timeout_ms: 2000,
max_idle_connections_per_host: 4,
max_concurrent_requests_per_endpoint: 2,
pause_after_http_429_ms: Some(1500),
}
}
#[tokio::test]
async fn pool_selects_only_matching_active_clients() {
let endpoint_a = make_http_endpoint(
"endpoint_a",
"provider_a",
"http://127.0.0.1:65531".to_string(),
vec!["http_queries".to_string()],
);
let endpoint_b = make_http_endpoint(
"endpoint_b",
"provider_b",
"http://127.0.0.1:65532".to_string(),
vec!["http_transactions".to_string()],
);
let endpoint_c = make_http_endpoint(
"endpoint_c",
"provider_c",
"http://127.0.0.1:65533".to_string(),
vec!["http_queries".to_string()],
);
let client_a = crate::HttpClient::new(endpoint_a).expect("client_a creation must succeed");
let client_b = crate::HttpClient::new(endpoint_b).expect("client_b creation must succeed");
let client_c = crate::HttpClient::new(endpoint_c).expect("client_c creation must succeed");
client_c.pause_for(5000).await;
let pool = crate::HttpEndpointPool::new(vec![client_a.clone(), client_b, client_c])
.expect("pool creation must succeed");
let selected_client = pool
.select_client_for_role_and_method("http_queries", "getSlot")
.await
.expect("selection must succeed");
assert_eq!(selected_client.endpoint_name(), "endpoint_a");
}
#[tokio::test]
async fn pool_round_robins_between_two_active_clients() {
let endpoint_a = make_http_endpoint(
"endpoint_a",
"provider_a",
"http://127.0.0.1:65534".to_string(),
vec!["http_queries".to_string()],
);
let endpoint_b = make_http_endpoint(
"endpoint_b",
"provider_b",
"http://127.0.0.1:65535".to_string(),
vec!["http_queries".to_string()],
);
let client_a = crate::HttpClient::new(endpoint_a).expect("client_a creation must succeed");
let client_b = crate::HttpClient::new(endpoint_b).expect("client_b creation must succeed");
let pool = crate::HttpEndpointPool::new(vec![client_a, client_b])
.expect("pool creation must succeed");
let first = pool
.select_client_for_role_and_method("http_queries", "getSlot")
.await
.expect("first selection must succeed");
let second = pool
.select_client_for_role_and_method("http_queries", "getSlot")
.await
.expect("second selection must succeed");
assert_ne!(first.endpoint_name(), second.endpoint_name());
}
#[tokio::test]
async fn pool_snapshot_reports_statuses() {
let endpoint_a = make_http_endpoint(
"endpoint_a",
"provider_a",
"http://127.0.0.1:65001".to_string(),
vec!["http_queries".to_string()],
);
let endpoint_b = make_http_endpoint(
"endpoint_b",
"provider_b",
"http://127.0.0.1:65002".to_string(),
vec!["http_queries".to_string()],
);
let client_a = crate::HttpClient::new(endpoint_a).expect("client_a creation must succeed");
let client_b = crate::HttpClient::new(endpoint_b).expect("client_b creation must succeed");
client_b.disable().await;
let pool = crate::HttpEndpointPool::new(vec![client_a, client_b])
.expect("pool creation must succeed");
let snapshots = pool.snapshot().await;
assert_eq!(snapshots.len(), 2);
assert!(snapshots.iter().any(|snapshot| snapshot.status == "Active"));
assert!(
snapshots
.iter()
.any(|snapshot| snapshot.status == "Disabled")
);
}
#[tokio::test]
async fn pool_executes_get_health_for_role() {
let server_a = TestHttpServer::spawn("server_a".to_string()).await;
let server_b = TestHttpServer::spawn("server_b".to_string()).await;
let endpoint_a = make_http_endpoint(
"endpoint_a",
"provider_a",
server_a.url.clone(),
vec!["http_queries".to_string()],
);
let endpoint_b = make_http_endpoint(
"endpoint_b",
"provider_b",
server_b.url.clone(),
vec!["http_transactions".to_string()],
);
let pool = crate::HttpEndpointPool::from_endpoint_configs(vec![endpoint_a, endpoint_b])
.expect("pool creation must succeed");
let health = pool
.get_health_for_role("http_queries")
.await
.expect("pool get_health_for_role must succeed");
assert_eq!(health, "ok-server_a".to_string());
server_a.shutdown().await;
server_b.shutdown().await;
}
#[tokio::test]
async fn pool_executes_send_transaction_for_role() {
let server_a = TestHttpServer::spawn("server_a".to_string()).await;
let server_b = TestHttpServer::spawn("server_b".to_string()).await;
let endpoint_a = make_http_endpoint(
"endpoint_a",
"provider_a",
server_a.url.clone(),
vec!["http_queries".to_string()],
);
let endpoint_b = make_http_endpoint(
"endpoint_b",
"provider_b",
server_b.url.clone(),
vec!["http_transactions".to_string()],
);
let pool = crate::HttpEndpointPool::from_endpoint_configs(vec![endpoint_a, endpoint_b])
.expect("pool creation must succeed");
let signature = pool
.send_transaction_for_role("http_transactions", "AAAA".to_string(), None)
.await
.expect("pool send_transaction_for_role must succeed");
assert_eq!(signature, "sig-server_b".to_string());
server_a.shutdown().await;
server_b.shutdown().await;
}
#[tokio::test]
async fn pool_returns_error_when_no_active_client_matches_role() {
let endpoint_a = make_http_endpoint(
"endpoint_a",
"provider_a",
"http://127.0.0.1:65101".to_string(),
vec!["http_queries".to_string()],
);
let client_a = crate::HttpClient::new(endpoint_a).expect("client creation must succeed");
client_a.disable().await;
let pool =
crate::HttpEndpointPool::new(vec![client_a]).expect("pool creation must succeed");
let result = pool
.select_client_for_role_and_method("http_queries", "getSlot")
.await;
assert!(result.is_err());
let error = result.expect_err("selection must fail");
match error {
crate::KbError::Http(message) => {
assert!(message.contains("no active http endpoint available"));
}
other => {
panic!("unexpected error: {other:?}");
}
}
}
}