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sglang/sgl-model-gateway/src/policies/cache_aware.rs
T

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31 KiB
Rust

/*
Cache-Aware Load Balancing Router
This router combines two strategies to optimize both cache utilization and request distribution:
1. Cache-Aware Routing (Approximate Tree)
2. Load Balancing (Shortest Queue with Balance Thresholds)
The router dynamically switches between these strategies based on load conditions:
- Uses load balancing when the system is imbalanced
- Uses cache-aware routing when the system is balanced
A system is considered imbalanced if both conditions are met:
1. (max - min) > abs_threshold
2. max > rel_threshold * min
Strategy Details:
1. Cache-Aware Routing (Approximate Tree)
-------------------------------------------
This strategy maintains an approximate radix tree for each worker based on request history,
eliminating the need for direct cache state queries. The tree stores raw text characters
instead of token IDs to avoid tokenization overhead.
Process:
a. For each request, find the worker with the highest prefix match
b. If match rate > cache_threshold:
Route to the worker with highest match (likely has relevant data cached)
c. If match rate ≤ cache_threshold:
Route to the worker with smallest tree size (most available cache capacity)
d. Background maintenance:
Periodically evict least recently used leaf nodes to prevent memory overflow
2. Load Balancing (Shortest Queue)
-------------------------------------------
This strategy tracks pending request counts per worker and routes new requests
to the least busy worker when the system is detected to be imbalanced.
Configuration Parameters:
------------------------
1. cache_threshold: (float, 0.0 to 1.0)
Minimum prefix match ratio to use highest-match routing.
Below this threshold, routes to worker with most available cache space.
2. balance_abs_threshold: (integer)
Absolute difference threshold for load imbalance detection.
System is potentially imbalanced if (max_load - min_load) > abs_threshold
3. balance_rel_threshold: (float)
Relative ratio threshold for load imbalance detection.
System is potentially imbalanced if max_load > min_load * rel_threshold
Used in conjunction with abs_threshold to determine final imbalance state.
4. eviction_interval_secs: (integer)
Interval between LRU eviction cycles for the approximate trees.
5. max_tree_size: (integer)
Maximum nodes per tree. When exceeded, LRU leaf nodes are evicted
during the next eviction cycle.
*/
use std::sync::Arc;
use async_trait::async_trait;
use dashmap::DashMap;
use rand::Rng;
use smg_mesh::{tree_ops::TreeOperation, OptionalMeshSyncManager};
use tracing::{debug, warn};
use super::{
get_healthy_worker_indices, normalize_model_key, tree::Tree, utils::PeriodicTask,
CacheAwareConfig, LoadBalancingPolicy, SelectWorkerInfo,
};
use crate::core::{Worker, UNKNOWN_MODEL_ID};
/// Cache-aware routing policy
///
/// Routes requests based on cache affinity when load is balanced,
/// switches to shortest-queue routing when load is imbalanced.
/// Maintains separate trees per model for multi-model support.
/// Supports mesh synchronization of tree operations across cluster nodes.
/// When mesh is not enabled, the policy works independently without synchronization.
#[derive(Debug)]
pub struct CacheAwarePolicy {
config: CacheAwareConfig,
trees: Arc<DashMap<String, Arc<Tree>>>,
mesh_sync: OptionalMeshSyncManager,
_eviction_task: Option<PeriodicTask>,
}
impl CacheAwarePolicy {
pub fn new() -> Self {
Self::with_config(CacheAwareConfig::default())
}
pub fn with_config(config: CacheAwareConfig) -> Self {
let trees = Arc::new(DashMap::<String, Arc<Tree>>::new());
// Start background eviction thread if configured
let eviction_task = if config.eviction_interval_secs > 0 {
let trees_clone = Arc::clone(&trees);
let max_tree_size = config.max_tree_size;
Some(PeriodicTask::spawn(
config.eviction_interval_secs,
"Eviction",
move || {
for tree_ref in trees_clone.iter() {
let model_id = tree_ref.key();
let tree = tree_ref.value();
tree.evict_tenant_by_size(max_tree_size);
debug!(
"Cache eviction completed for model {}, max_size: {}",
model_id, max_tree_size
);
}
},
))
} else {
None
};
Self {
config,
trees,
mesh_sync: None,
_eviction_task: eviction_task,
}
}
/// Set mesh sync manager (can be called after construction)
pub fn set_mesh_sync(&mut self, mesh_sync: OptionalMeshSyncManager) {
self.mesh_sync = mesh_sync.clone();
if mesh_sync.is_some() {
self.restore_tree_state_from_mesh();
}
}
/// Initialize the tree with worker URLs (used only during initial setup)
pub fn init_workers(&self, workers: &[Arc<dyn Worker>]) {
// Group workers by model
let mut model_workers: std::collections::HashMap<String, Vec<&Arc<dyn Worker>>> =
std::collections::HashMap::new();
for worker in workers {
let tree_key = normalize_model_key(worker.model_id());
model_workers
.entry(tree_key.to_string())
.or_default()
.push(worker);
}
// Initialize tree for each model
for (tree_key, model_workers) in model_workers {
let tree = self
.trees
.entry(tree_key)
.or_insert_with(|| Arc::new(Tree::new()));
for worker in model_workers {
tree.insert("", worker.url());
}
}
}
/// Add a single worker to the tree (incremental update)
pub fn add_worker(&self, worker: &dyn Worker) {
let tree_key = normalize_model_key(worker.model_id());
let tree = self
.trees
.entry(tree_key.to_string())
.or_insert_with(|| Arc::new(Tree::new()));
tree.insert("", worker.url());
}
/// Add a worker by URL and model (for backward compatibility)
pub fn add_worker_by_url(&self, url: &str, model_id: &str) {
let tree = self
.trees
.entry(model_id.to_string())
.or_insert_with(|| Arc::new(Tree::new()));
tree.insert("", url);
}
/// Remove a worker from the tree
pub fn remove_worker(&self, worker: &dyn Worker) {
let tree_key = normalize_model_key(worker.model_id());
if let Some(tree) = self.trees.get(tree_key) {
tree.remove_tenant(worker.url());
}
}
/// Remove a worker by URL (removes from all model trees for backward compatibility)
pub fn remove_worker_by_url(&self, url: &str) {
// Remove from all trees since we don't know which model it belongs to
for tree_ref in self.trees.iter() {
tree_ref.value().remove_tenant(url);
}
}
/// Restore tree state from mesh store
/// This is called during initialization to rebuild trees from synchronized state
fn restore_tree_state_from_mesh(&self) {
if let Some(ref mesh_sync) = self.mesh_sync {
// Get all tree states from mesh
// We need to iterate through all models that have tree states
// For now, we'll restore trees for models that are already in our trees map
// In a full implementation, we might want to query mesh for all tree states
for tree_ref in self.trees.iter() {
let model_id = tree_ref.key();
if let Some(tree_state) = mesh_sync.get_tree_state(model_id) {
debug!(
"Restoring tree state for model {} with {} operations",
model_id,
tree_state.operations.len()
);
let tree = tree_ref.value();
// Apply all operations to rebuild the tree
for operation in &tree_state.operations {
match operation {
TreeOperation::Insert(insert_op) => {
tree.insert(&insert_op.text, &insert_op.tenant);
}
TreeOperation::Remove(remove_op) => {
tree.remove_tenant(&remove_op.tenant);
}
}
}
}
}
}
}
/// Normalize model_id for mesh synchronization
/// Converts empty model_id to UNKNOWN_MODEL_ID for consistency
fn normalize_mesh_model_id(model_id: &str) -> &str {
if model_id.is_empty() {
UNKNOWN_MODEL_ID
} else {
model_id
}
}
/// Apply remote tree operation from mesh
/// This is called when receiving tree state updates from other nodes
pub fn apply_remote_tree_operation(&self, model_id: &str, operation: &TreeOperation) {
let tree_key = Self::normalize_mesh_model_id(model_id);
let tree = self
.trees
.entry(tree_key.to_string())
.or_insert_with(|| Arc::new(Tree::new()));
match operation {
TreeOperation::Insert(insert_op) => {
tree.insert(&insert_op.text, &insert_op.tenant);
debug!(
"Applied remote tree insert: model={}, text={}, tenant={}",
model_id, insert_op.text, insert_op.tenant
);
}
TreeOperation::Remove(remove_op) => {
tree.remove_tenant(&remove_op.tenant);
debug!(
"Applied remote tree remove: model={}, tenant={}",
model_id, remove_op.tenant
);
}
}
}
/// Run cache eviction to prevent unbounded growth
pub fn evict_cache(&self, max_size: usize) {
for tree_ref in self.trees.iter() {
let model_id = tree_ref.key();
let tree = tree_ref.value();
tree.evict_tenant_by_size(max_size);
debug!(
"Cache eviction for model {}, max_size: {}",
model_id, max_size
);
}
}
fn select_worker_min_load(
&self,
workers: &[Arc<dyn Worker>],
request_text: &Option<&str>,
healthy_indices: &[usize],
model_id: &str,
max_load: usize,
min_load: usize,
) -> Option<usize> {
// Log load balancing trigger (only compute worker loads if debug enabled)
if tracing::enabled!(tracing::Level::DEBUG) {
let worker_loads: Vec<(&str, usize)> =
workers.iter().map(|w| (w.url(), w.load())).collect();
debug!(
"Load balancing triggered | max: {} | min: {} | workers: {:?}",
max_load, min_load, worker_loads
);
}
// Use shortest queue when imbalanced
let min_load_idx = healthy_indices
.iter()
.min_by_key(|&&idx| workers[idx].load())
.copied()?;
// Even in imbalanced mode, update the tree to maintain cache state
if let Some(text) = request_text {
// Get the tree reference without locking the entire HashMap
// DashMap only locks the specific shard containing this key
let tree = self.trees.get(model_id).map(|entry| entry.value().clone());
if let Some(tree) = tree {
let worker_url = workers[min_load_idx].url();
// Now we can work with the tree without holding the HashMap lock
tree.insert(text, worker_url);
// Sync insert operation to mesh if enabled (no-op if mesh is not enabled)
if let Some(ref mesh_sync) = self.mesh_sync {
use smg_mesh::tree_ops::TreeInsertOp;
let op = TreeOperation::Insert(TreeInsertOp {
text: text.to_string(),
tenant: worker_url.to_string(),
});
let mesh_model_id = Self::normalize_mesh_model_id(model_id);
if let Err(e) = mesh_sync.sync_tree_operation(mesh_model_id.to_string(), op) {
warn!("Failed to sync tree insert operation to mesh: {}", e);
}
}
} else {
debug!(
"Warning: No tree found for model '{}', skipping cache update",
model_id
);
}
}
// Increment processed counter
workers[min_load_idx].increment_processed();
Some(min_load_idx)
}
}
#[async_trait]
impl LoadBalancingPolicy for CacheAwarePolicy {
async fn select_worker(
&self,
workers: &[Arc<dyn Worker>],
info: &SelectWorkerInfo<'_>,
) -> Option<usize> {
let request_text = info.request_text;
let healthy_indices = get_healthy_worker_indices(workers);
if healthy_indices.is_empty() {
return None;
}
// Determine the model for this set of workers (router pre-filters by model)
// All workers should be from the same model
let model_id = normalize_model_key(workers[healthy_indices[0]].model_id());
// Get current load statistics - compute min/max in single pass without allocation
let (min_load, max_load) = workers.iter().fold((usize::MAX, 0usize), |(min, max), w| {
let load = w.load();
(min.min(load), max.max(load))
});
let min_load = if min_load == usize::MAX { 0 } else { min_load };
// Check if load is imbalanced
let is_imbalanced = max_load.saturating_sub(min_load) > self.config.balance_abs_threshold
&& (max_load as f32) > (min_load as f32 * self.config.balance_rel_threshold);
if is_imbalanced {
return self.select_worker_min_load(
workers,
&request_text,
&healthy_indices,
model_id,
max_load,
min_load,
);
}
// Use cache-aware routing when balanced
let text = request_text.unwrap_or("");
// Get the tree reference without locking the entire HashMap
// DashMap only locks the specific shard containing this key
let tree = self.trees.get(model_id).map(|entry| entry.value().clone());
if let Some(tree) = tree {
// Now we work with the tree without holding the HashMap lock
// Use prefix_match_with_counts to avoid redundant chars().count() calls
let result = tree.prefix_match_with_counts(text);
let match_rate = if result.input_char_count == 0 {
0.0
} else {
result.matched_char_count as f32 / result.input_char_count as f32
};
// Select worker without String allocation
let selected_idx = if match_rate > self.config.cache_threshold {
// Cache hit path: find worker by URL (compare &str directly, no allocation)
let tenant_url: &str = &result.tenant;
workers
.iter()
.position(|w| w.url() == tenant_url)
.filter(|&idx| workers[idx].is_healthy())
} else {
// Low cache match: use worker with minimum load
healthy_indices
.iter()
.min_by_key(|&&idx| workers[idx].load())
.copied()
};
if let Some(idx) = selected_idx {
// Update the tree with this request (use worker URL directly, no allocation)
tree.insert(text, workers[idx].url());
// Sync insert operation to mesh if enabled (no-op if mesh is not enabled)
if let Some(ref mesh_sync) = self.mesh_sync {
use smg_mesh::tree_ops::TreeInsertOp;
let op = TreeOperation::Insert(TreeInsertOp {
text: text.to_string(),
tenant: workers[idx].url().to_string(),
});
let mesh_model_id = Self::normalize_mesh_model_id(model_id);
if let Err(e) = mesh_sync.sync_tree_operation(mesh_model_id.to_string(), op) {
warn!("Failed to sync tree insert operation to mesh: {}", e);
}
}
// Increment processed counter
workers[idx].increment_processed();
return Some(idx);
}
// Selected worker no longer exists or unhealthy, remove stale tenant from tree
if match_rate > self.config.cache_threshold {
let tenant_url: &str = &result.tenant;
tree.remove_tenant(tenant_url);
debug!("Removed stale worker {} from cache tree", tenant_url);
// Sync removal to mesh if enabled (no-op if mesh is not enabled)
if let Some(ref mesh_sync) = self.mesh_sync {
use smg_mesh::tree_ops::TreeRemoveOp;
let op = TreeOperation::Remove(TreeRemoveOp {
tenant: tenant_url.to_string(),
});
let mesh_model_id = Self::normalize_mesh_model_id(model_id);
if let Err(e) = mesh_sync.sync_tree_operation(mesh_model_id.to_string(), op) {
warn!("Failed to sync tree remove operation to mesh: {}", e);
}
}
}
// Fallback to first healthy worker
healthy_indices.first().copied()
} else {
// No tree for this model, log warning and use random selection
debug!(
"Warning: No tree found for model '{}', using random worker selection",
model_id
);
// Return a random healthy worker
let mut rng = rand::rng();
let random_idx = rng.random_range(0..healthy_indices.len());
Some(healthy_indices[random_idx])
}
}
fn on_request_complete(&self, worker_url: &str, success: bool) {
// Could track success rates per worker for more intelligent routing
if !success {
// Optionally reduce affinity for failed requests
tracing::debug!(
"Request to {} completed with success={}",
worker_url,
success
);
}
}
fn name(&self) -> &'static str {
"cache_aware"
}
fn needs_request_text(&self) -> bool {
true // Cache-aware policy needs request text for cache affinity
}
fn as_any(&self) -> &dyn std::any::Any {
self
}
}
impl Default for CacheAwarePolicy {
fn default() -> Self {
Self::new()
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::core::{BasicWorkerBuilder, WorkerType};
#[tokio::test]
async fn test_cache_aware_with_balanced_load() {
// Create policy without eviction thread for testing
let config = CacheAwareConfig {
eviction_interval_secs: 0, // Disable eviction thread
..Default::default()
};
let policy = CacheAwarePolicy::with_config(config);
let workers: Vec<Arc<dyn Worker>> = vec![
Arc::new(
BasicWorkerBuilder::new("http://w1:8000")
.worker_type(WorkerType::Regular)
.api_key("test_api_key")
.build(),
),
Arc::new(
BasicWorkerBuilder::new("http://w2:8000")
.worker_type(WorkerType::Regular)
.api_key("test_api_key")
.build(),
),
];
// Initialize the policy with workers
policy.init_workers(&workers);
// First request should be distributed
let idx1 = policy
.select_worker(
&workers,
&SelectWorkerInfo {
request_text: Some("hello world"),
..Default::default()
},
)
.await
.unwrap();
// Same request should go to same worker (cache hit)
let idx2 = policy
.select_worker(
&workers,
&SelectWorkerInfo {
request_text: Some("hello world"),
..Default::default()
},
)
.await
.unwrap();
assert_eq!(idx1, idx2);
// Similar request should also go to same worker
let idx3 = policy
.select_worker(
&workers,
&SelectWorkerInfo {
request_text: Some("hello"),
..Default::default()
},
)
.await
.unwrap();
assert_eq!(idx1, idx3);
}
#[tokio::test]
async fn test_cache_aware_with_imbalanced_load() {
let policy = CacheAwarePolicy::with_config(CacheAwareConfig {
cache_threshold: 0.5,
balance_abs_threshold: 5,
balance_rel_threshold: 2.0,
eviction_interval_secs: 0, // Disable eviction thread
max_tree_size: 10000,
});
let worker1 = BasicWorkerBuilder::new("http://w1:8000")
.worker_type(WorkerType::Regular)
.build();
let worker2 = BasicWorkerBuilder::new("http://w2:8000")
.worker_type(WorkerType::Regular)
.build();
// Create significant load imbalance
for _ in 0..20 {
worker1.increment_load();
}
// worker2 has load 0
let workers: Vec<Arc<dyn Worker>> = vec![Arc::new(worker1), Arc::new(worker2)];
policy.init_workers(&workers);
// Should select worker2 (lower load) despite cache affinity
let info = SelectWorkerInfo {
request_text: Some("test"),
..Default::default()
};
for _ in 0..5 {
let idx = policy.select_worker(&workers, &info).await.unwrap();
assert_eq!(idx, 1); // Should always pick worker2
}
}
#[tokio::test]
async fn test_cache_aware_worker_removal() {
let config = CacheAwareConfig {
eviction_interval_secs: 0, // Disable eviction thread
..Default::default()
};
let policy = CacheAwarePolicy::with_config(config);
let workers: Vec<Arc<dyn Worker>> = vec![
Arc::new(
BasicWorkerBuilder::new("http://w1:8000")
.worker_type(WorkerType::Regular)
.build(),
),
Arc::new(
BasicWorkerBuilder::new("http://w2:8000")
.worker_type(WorkerType::Regular)
.build(),
),
];
policy.init_workers(&workers);
// Route some requests
policy
.select_worker(
&workers,
&SelectWorkerInfo {
request_text: Some("test1"),
..Default::default()
},
)
.await;
policy
.select_worker(
&workers,
&SelectWorkerInfo {
request_text: Some("test2"),
..Default::default()
},
)
.await;
// Remove a worker
policy.remove_worker_by_url("http://w1:8000");
workers[0].set_healthy(false);
// All requests should now go to worker2
let idx = policy
.select_worker(
&workers,
&SelectWorkerInfo {
request_text: Some("test1"),
..Default::default()
},
)
.await
.unwrap();
assert_eq!(idx, 1);
}
#[tokio::test]
async fn test_cache_aware_sync_tree_operation_to_mesh() {
use std::sync::Arc;
use smg_mesh::{stores::StateStores, sync::MeshSyncManager};
let stores = Arc::new(StateStores::with_self_name("node1".to_string()));
let mesh_sync = Arc::new(MeshSyncManager::new(stores, "node1".to_string()));
let config = CacheAwareConfig {
eviction_interval_secs: 0,
..Default::default()
};
let mut policy = CacheAwarePolicy::with_config(config);
policy.set_mesh_sync(Some(mesh_sync.clone()));
let workers: Vec<Arc<dyn Worker>> = vec![Arc::new(
BasicWorkerBuilder::new("http://w1:8000")
.worker_type(WorkerType::Regular)
.api_key("test_api_key")
.build(),
)];
policy.init_workers(&workers);
// Select worker with a request - should sync to mesh
let _idx = policy
.select_worker(
&workers,
&SelectWorkerInfo {
request_text: Some("test request"),
..Default::default()
},
)
.await
.unwrap();
// Verify tree operation was synced to mesh (under UNKNOWN_MODEL_ID since no model was specified)
let tree_state = mesh_sync.get_tree_state(UNKNOWN_MODEL_ID);
assert!(tree_state.is_some());
let tree = tree_state.unwrap();
assert!(!tree.operations.is_empty());
}
#[test]
fn test_cache_aware_restore_tree_state_from_mesh() {
use std::sync::Arc;
use smg_mesh::{
stores::StateStores,
sync::MeshSyncManager,
tree_ops::{TreeInsertOp, TreeOperation},
};
let stores = Arc::new(StateStores::with_self_name("node1".to_string()));
let mesh_sync = Arc::new(MeshSyncManager::new(stores, "node1".to_string()));
// Pre-populate mesh with tree state
let op1 = TreeOperation::Insert(TreeInsertOp {
text: "test_text_1".to_string(),
tenant: "http://w1:8000".to_string(),
});
mesh_sync
.sync_tree_operation("model1".to_string(), op1)
.unwrap();
let op2 = TreeOperation::Insert(TreeInsertOp {
text: "test_text_2".to_string(),
tenant: "http://w2:8000".to_string(),
});
mesh_sync
.sync_tree_operation("model1".to_string(), op2)
.unwrap();
let config = CacheAwareConfig {
eviction_interval_secs: 0,
..Default::default()
};
let mut policy = CacheAwarePolicy::with_config(config);
policy.set_mesh_sync(Some(mesh_sync.clone()));
// Initialize with a model to trigger restore
let _workers: Vec<Arc<dyn Worker>> = vec![Arc::new(
BasicWorkerBuilder::new("http://w1:8000")
.worker_type(WorkerType::Regular)
.api_key("test_api_key")
.build(),
)];
// Create a tree entry for model1 to trigger restore
let _tree = policy
.trees
.entry("model1".to_string())
.or_insert_with(|| Arc::new(Tree::new()));
// Manually trigger restore (normally done in constructor)
// For testing, we'll verify the tree state exists in mesh
let tree_state = mesh_sync.get_tree_state("model1");
assert!(tree_state.is_some());
let state = tree_state.unwrap();
assert_eq!(state.operations.len(), 2);
}
#[test]
fn test_cache_aware_apply_remote_tree_operation() {
use std::sync::Arc;
use smg_mesh::{
stores::StateStores,
sync::MeshSyncManager,
tree_ops::{TreeInsertOp, TreeOperation},
};
let stores = Arc::new(StateStores::with_self_name("node1".to_string()));
let mesh_sync = Arc::new(MeshSyncManager::new(stores, "node1".to_string()));
let config = CacheAwareConfig {
eviction_interval_secs: 0,
..Default::default()
};
let mut policy = CacheAwarePolicy::with_config(config);
policy.set_mesh_sync(Some(mesh_sync.clone()));
// Apply remote tree operation
let remote_op = TreeOperation::Insert(TreeInsertOp {
text: "remote_text".to_string(),
tenant: "http://remote:8000".to_string(),
});
policy.apply_remote_tree_operation("model1", &remote_op);
// Verify the tree was updated
let tree = policy.trees.get("model1");
assert!(tree.is_some());
}
#[test]
fn test_cache_aware_multi_node_consistency() {
use std::sync::Arc;
use smg_mesh::{
stores::StateStores,
sync::MeshSyncManager,
tree_ops::{TreeInsertOp, TreeOperation},
};
// Simulate two nodes
let stores1 = Arc::new(StateStores::with_self_name("node1".to_string()));
let mesh_sync1 = Arc::new(MeshSyncManager::new(stores1.clone(), "node1".to_string()));
let stores2 = Arc::new(StateStores::with_self_name("node2".to_string()));
let mesh_sync2 = Arc::new(MeshSyncManager::new(stores2.clone(), "node2".to_string()));
let config = CacheAwareConfig {
eviction_interval_secs: 0,
..Default::default()
};
let mut _policy1 = CacheAwarePolicy::with_config(config.clone());
_policy1.set_mesh_sync(Some(mesh_sync1.clone()));
let mut _policy2 = CacheAwarePolicy::with_config(config);
_policy2.set_mesh_sync(Some(mesh_sync2.clone()));
// Node1 syncs a tree operation
let op = TreeOperation::Insert(TreeInsertOp {
text: "shared_text".to_string(),
tenant: "http://shared:8000".to_string(),
});
mesh_sync1
.sync_tree_operation("model1".to_string(), op.clone())
.unwrap();
// Node2 should be able to get the tree state
let tree_state = mesh_sync2.get_tree_state("model1");
// Note: In a real scenario, this would be synced via gossip protocol
// For unit test, we verify the sync mechanism works
// Tree state may or may not exist depending on sync timing
let _ = tree_state;
}
#[tokio::test]
async fn test_cache_aware_without_mesh() {
let config = CacheAwareConfig {
eviction_interval_secs: 0,
..Default::default()
};
let policy = CacheAwarePolicy::with_config(config);
let workers: Vec<Arc<dyn Worker>> = vec![Arc::new(
BasicWorkerBuilder::new("http://w1:8000")
.worker_type(WorkerType::Regular)
.api_key("test_api_key")
.build(),
)];
policy.init_workers(&workers);
// Should work without mesh
let idx = policy
.select_worker(
&workers,
&SelectWorkerInfo {
request_text: Some("test request"),
..Default::default()
},
)
.await
.unwrap();
assert_eq!(idx, 0);
}
}