oxirs_vec/
distributed_vector_search.rs

1//! Distributed Vector Search - Version 1.1 Roadmap Feature
2//!
3//! This module implements distributed vector search capabilities for scaling
4//! vector operations across multiple nodes and data centers.
5
6use crate::{
7    advanced_analytics::VectorAnalyticsEngine,
8    similarity::{SimilarityMetric, SimilarityResult},
9    Vector,
10};
11
12use anyhow::Result;
13use serde::{Deserialize, Serialize};
14use std::collections::HashMap;
15use std::sync::{Arc, RwLock};
16use std::time::{Duration, Instant, SystemTime};
17use tokio::sync::Mutex;
18use tracing::{debug, error, info};
19
20/// Distributed node configuration
21#[derive(Debug, Clone, Serialize, Deserialize)]
22pub struct DistributedNodeConfig {
23    /// Unique node identifier
24    pub node_id: String,
25    /// Node endpoint URL
26    pub endpoint: String,
27    /// Node region/datacenter
28    pub region: String,
29    /// Node capacity (max vectors)
30    pub capacity: usize,
31    /// Current load factor (0.0 to 1.0)
32    pub load_factor: f32,
33    /// Network latency to this node (ms)
34    pub latency_ms: u64,
35    /// Node health status
36    pub health_status: NodeHealthStatus,
37    /// Replication factor
38    pub replication_factor: usize,
39}
40
41/// Node health status
42#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
43pub enum NodeHealthStatus {
44    Healthy,
45    Degraded,
46    Unhealthy,
47    Offline,
48}
49
50/// Distributed search query
51#[derive(Debug, Clone)]
52pub struct DistributedQuery {
53    pub id: String,
54    pub query_vector: Vector,
55    pub k: usize,
56    pub similarity_metric: SimilarityMetric,
57    pub filters: HashMap<String, String>,
58    pub timeout: Duration,
59    pub consistency_level: ConsistencyLevel,
60}
61
62/// Consistency levels for distributed queries
63#[derive(Debug, Clone, Copy)]
64pub enum ConsistencyLevel {
65    /// Read from any available node
66    Eventual,
67    /// Read from majority of nodes
68    Quorum,
69    /// Read from all nodes
70    Strong,
71}
72
73/// Search result from a distributed node
74#[derive(Debug, Clone)]
75pub struct NodeSearchResult {
76    pub node_id: String,
77    pub results: Vec<SimilarityResult>,
78    pub latency_ms: u64,
79    pub error: Option<String>,
80}
81
82/// Distributed search response
83#[derive(Debug, Clone)]
84pub struct DistributedSearchResponse {
85    pub query_id: String,
86    pub merged_results: Vec<SimilarityResult>,
87    pub node_results: Vec<NodeSearchResult>,
88    pub total_latency_ms: u64,
89    pub nodes_queried: usize,
90    pub nodes_responded: usize,
91}
92
93/// Partitioning strategy for vector distribution
94#[derive(Debug, Clone)]
95pub enum PartitioningStrategy {
96    /// Hash-based partitioning
97    Hash,
98    /// Range-based partitioning
99    Range,
100    /// Consistent hashing
101    ConsistentHash,
102    /// Geography-based partitioning
103    Geographic,
104    /// Custom partitioning function
105    Custom(fn(&Vector) -> String),
106}
107
108/// Distributed vector search coordinator
109pub struct DistributedVectorSearch {
110    /// Node registry
111    nodes: Arc<RwLock<HashMap<String, DistributedNodeConfig>>>,
112    /// Partitioning strategy
113    partitioning_strategy: PartitioningStrategy,
114    /// Load balancer
115    load_balancer: Arc<Mutex<LoadBalancer>>,
116    /// Replication manager
117    replication_manager: Arc<Mutex<ReplicationManager>>,
118    /// Query router
119    query_router: Arc<QueryRouter>,
120    /// Health monitor
121    health_monitor: Arc<Mutex<HealthMonitor>>,
122    /// Performance analytics
123    analytics: Arc<Mutex<VectorAnalyticsEngine>>,
124}
125
126/// Load balancer for distributed queries
127#[derive(Debug)]
128pub struct LoadBalancer {
129    /// Load balancing algorithm
130    algorithm: LoadBalancingAlgorithm,
131    /// Node usage statistics
132    node_stats: HashMap<String, NodeStats>,
133}
134
135/// Load balancing algorithms
136#[derive(Debug, Clone)]
137pub enum LoadBalancingAlgorithm {
138    RoundRobin,
139    LeastConnections,
140    WeightedRoundRobin,
141    LatencyBased,
142    ResourceBased,
143}
144
145/// Node statistics for load balancing
146#[derive(Debug, Clone)]
147pub struct NodeStats {
148    pub active_queries: u64,
149    pub average_latency_ms: f64,
150    pub success_rate: f64,
151    pub last_updated: SystemTime,
152}
153
154/// Replication manager for data consistency
155#[derive(Debug)]
156pub struct ReplicationManager {
157    /// Replication configurations per partition
158    partition_replicas: HashMap<String, Vec<String>>,
159    /// Consistency policies
160    consistency_policies: HashMap<String, ConsistencyLevel>,
161}
162
163/// Query router for distributed search
164pub struct QueryRouter {
165    /// Routing table
166    routing_table: Arc<RwLock<HashMap<String, Vec<String>>>>,
167    /// Query execution strategy
168    execution_strategy: QueryExecutionStrategy,
169}
170
171/// Query execution strategies
172#[derive(Debug, Clone)]
173pub enum QueryExecutionStrategy {
174    /// Execute on all relevant nodes in parallel
175    Parallel,
176    /// Execute on nodes sequentially with early termination
177    Sequential,
178    /// Adaptive execution based on query characteristics
179    Adaptive,
180}
181
182/// Health monitor for distributed nodes
183#[derive(Debug)]
184pub struct HealthMonitor {
185    /// Health check interval
186    check_interval: Duration,
187    /// Health check timeout
188    check_timeout: Duration,
189    /// Node health history
190    health_history: HashMap<String, Vec<HealthCheckResult>>,
191}
192
193/// Health check result
194#[derive(Debug, Clone)]
195pub struct HealthCheckResult {
196    pub timestamp: SystemTime,
197    pub latency_ms: u64,
198    pub success: bool,
199    pub error_message: Option<String>,
200}
201
202impl DistributedVectorSearch {
203    /// Create new distributed vector search coordinator
204    pub fn new(partitioning_strategy: PartitioningStrategy) -> Result<Self> {
205        Ok(Self {
206            nodes: Arc::new(RwLock::new(HashMap::new())),
207            partitioning_strategy,
208            load_balancer: Arc::new(Mutex::new(LoadBalancer::new(
209                LoadBalancingAlgorithm::LatencyBased,
210            ))),
211            replication_manager: Arc::new(Mutex::new(ReplicationManager::new())),
212            query_router: Arc::new(QueryRouter::new(QueryExecutionStrategy::Adaptive)),
213            health_monitor: Arc::new(Mutex::new(HealthMonitor::new(
214                Duration::from_secs(30),
215                Duration::from_secs(5),
216            ))),
217            analytics: Arc::new(Mutex::new(VectorAnalyticsEngine::new())),
218        })
219    }
220
221    /// Register a new node in the cluster
222    pub async fn register_node(&self, config: DistributedNodeConfig) -> Result<()> {
223        {
224            let mut nodes = self.nodes.write().unwrap();
225            info!("Registering node {} at {}", config.node_id, config.endpoint);
226            nodes.insert(config.node_id.clone(), config.clone());
227        } // Drop nodes lock before await
228
229        // Update load balancer
230        let mut load_balancer = self.load_balancer.lock().await;
231        load_balancer.add_node(&config.node_id);
232
233        // Update replication manager
234        let mut replication_manager = self.replication_manager.lock().await;
235        replication_manager.add_node(&config.node_id, config.replication_factor);
236
237        // Start health monitoring for the new node
238        let mut health_monitor = self.health_monitor.lock().await;
239        health_monitor.start_monitoring(&config.node_id);
240
241        Ok(())
242    }
243
244    /// Remove a node from the cluster
245    pub async fn deregister_node(&self, node_id: &str) -> Result<()> {
246        let config = {
247            let mut nodes = self.nodes.write().unwrap();
248            nodes.remove(node_id)
249        }; // Drop nodes lock before await
250
251        if let Some(config) = config {
252            info!("Deregistering node {} at {}", node_id, config.endpoint);
253
254            // Update load balancer
255            let mut load_balancer = self.load_balancer.lock().await;
256            load_balancer.remove_node(node_id);
257
258            // Update replication manager
259            let mut replication_manager = self.replication_manager.lock().await;
260            replication_manager.remove_node(node_id);
261
262            // Stop health monitoring
263            let mut health_monitor = self.health_monitor.lock().await;
264            health_monitor.stop_monitoring(node_id);
265        }
266
267        Ok(())
268    }
269
270    /// Execute distributed vector search
271    pub async fn search(&self, query: DistributedQuery) -> Result<DistributedSearchResponse> {
272        let start_time = Instant::now();
273
274        // Determine target nodes based on query and partitioning strategy
275        let target_nodes = self.select_target_nodes(&query).await?;
276
277        info!(
278            "Executing distributed query {} across {} nodes",
279            query.id,
280            target_nodes.len()
281        );
282
283        // Execute query on selected nodes
284        let node_results = match self.query_router.execution_strategy {
285            QueryExecutionStrategy::Parallel => {
286                self.execute_parallel_query(&query, &target_nodes).await?
287            }
288            QueryExecutionStrategy::Sequential => {
289                self.execute_sequential_query(&query, &target_nodes).await?
290            }
291            QueryExecutionStrategy::Adaptive => {
292                self.execute_adaptive_query(&query, &target_nodes).await?
293            }
294        };
295
296        // Merge results from all nodes
297        let merged_results = self.merge_node_results(&node_results, query.k);
298
299        // Update analytics
300        let analytics = crate::advanced_analytics::QueryAnalytics {
301            query_id: query.id.clone(),
302            timestamp: std::time::SystemTime::now()
303                .duration_since(std::time::UNIX_EPOCH)
304                .unwrap_or_default()
305                .as_secs(),
306            query_vector: query.query_vector.as_f32(),
307            similarity_metric: "distributed".to_string(),
308            top_k: query.k,
309            response_time: start_time.elapsed(),
310            results_count: merged_results.len(),
311            avg_similarity_score: merged_results.iter().map(|r| r.similarity).sum::<f32>()
312                / merged_results.len().max(1) as f32,
313            min_similarity_score: merged_results
314                .iter()
315                .map(|r| r.similarity)
316                .min_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal))
317                .unwrap_or(0.0),
318            max_similarity_score: merged_results
319                .iter()
320                .map(|r| r.similarity)
321                .max_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal))
322                .unwrap_or(0.0),
323            cache_hit: false,
324            index_type: "distributed".to_string(),
325        };
326        let mut analytics_guard = self.analytics.lock().await;
327        analytics_guard.record_query(analytics);
328
329        let nodes_responded = node_results.len();
330        Ok(DistributedSearchResponse {
331            query_id: query.id,
332            merged_results,
333            node_results,
334            total_latency_ms: start_time.elapsed().as_millis() as u64,
335            nodes_queried: target_nodes.len(),
336            nodes_responded,
337        })
338    }
339
340    /// Select target nodes for query execution
341    async fn select_target_nodes(&self, query: &DistributedQuery) -> Result<Vec<String>> {
342        let nodes = self.nodes.read().unwrap().clone();
343        let load_balancer = self.load_balancer.lock().await;
344
345        match &self.partitioning_strategy {
346            PartitioningStrategy::Hash => {
347                // Hash-based selection
348                let partition = self.compute_hash_partition(&query.query_vector);
349                self.get_nodes_for_partition(&partition, &nodes, &load_balancer)
350            }
351            PartitioningStrategy::Range => {
352                // Range-based selection
353                let partition = self.compute_range_partition(&query.query_vector);
354                self.get_nodes_for_partition(&partition, &nodes, &load_balancer)
355            }
356            PartitioningStrategy::ConsistentHash => {
357                // Consistent hash selection
358                let partition = self.compute_consistent_hash_partition(&query.query_vector);
359                self.get_nodes_for_partition(&partition, &nodes, &load_balancer)
360            }
361            PartitioningStrategy::Geographic => {
362                // Geographic-based selection (use all healthy nodes)
363                Ok(nodes
364                    .iter()
365                    .filter(|(_, config)| config.health_status == NodeHealthStatus::Healthy)
366                    .map(|(id, _)| id.clone())
367                    .collect())
368            }
369            PartitioningStrategy::Custom(_func) => {
370                // Custom partitioning function
371                Ok(nodes.keys().cloned().collect())
372            }
373        }
374    }
375
376    /// Execute query in parallel across nodes
377    async fn execute_parallel_query(
378        &self,
379        query: &DistributedQuery,
380        target_nodes: &[String],
381    ) -> Result<Vec<NodeSearchResult>> {
382        let mut handles = Vec::new();
383
384        for node_id in target_nodes {
385            let node_id = node_id.clone();
386            let query = query.clone();
387            let nodes = Arc::clone(&self.nodes);
388
389            let handle =
390                tokio::spawn(async move { Self::execute_node_query(node_id, query, nodes).await });
391
392            handles.push(handle);
393        }
394
395        let mut results = Vec::new();
396        for handle in handles {
397            match handle.await {
398                Ok(Ok(result)) => results.push(result),
399                Ok(Err(e)) => error!("Node query failed: {}", e),
400                Err(e) => error!("Task join failed: {}", e),
401            }
402        }
403
404        Ok(results)
405    }
406
407    /// Execute query sequentially across nodes
408    async fn execute_sequential_query(
409        &self,
410        query: &DistributedQuery,
411        target_nodes: &[String],
412    ) -> Result<Vec<NodeSearchResult>> {
413        let mut results = Vec::new();
414
415        for node_id in target_nodes {
416            match Self::execute_node_query(node_id.clone(), query.clone(), Arc::clone(&self.nodes))
417                .await
418            {
419                Ok(result) => {
420                    results.push(result);
421                    // Early termination if we have enough results
422                    if results.len() >= query.k {
423                        break;
424                    }
425                }
426                Err(e) => {
427                    error!("Node query failed for {}: {}", node_id, e);
428                    continue;
429                }
430            }
431        }
432
433        Ok(results)
434    }
435
436    /// Execute query with adaptive strategy
437    async fn execute_adaptive_query(
438        &self,
439        query: &DistributedQuery,
440        target_nodes: &[String],
441    ) -> Result<Vec<NodeSearchResult>> {
442        // For demonstration, use parallel for small node counts, sequential for large
443        if target_nodes.len() <= 5 {
444            self.execute_parallel_query(query, target_nodes).await
445        } else {
446            self.execute_sequential_query(query, target_nodes).await
447        }
448    }
449
450    /// Execute query on a specific node
451    async fn execute_node_query(
452        node_id: String,
453        query: DistributedQuery,
454        nodes: Arc<RwLock<HashMap<String, DistributedNodeConfig>>>,
455    ) -> Result<NodeSearchResult> {
456        let start_time = Instant::now();
457
458        // In a real implementation, this would make HTTP requests to the node
459        // For now, simulate the query execution
460
461        {
462            let nodes_guard = nodes.read().unwrap();
463            let _node_config = nodes_guard
464                .get(&node_id)
465                .ok_or_else(|| anyhow::anyhow!("Node {} not found", node_id))?;
466        } // Drop the guard here
467
468        // Simulate network latency and processing
469        tokio::time::sleep(Duration::from_millis(10)).await;
470
471        // Generate sample results
472        let mut results = Vec::new();
473        for i in 0..query.k.min(10) {
474            results.push(SimilarityResult {
475                id: format!(
476                    "dist_{}_{}_{}",
477                    node_id,
478                    i,
479                    std::time::SystemTime::now()
480                        .duration_since(std::time::UNIX_EPOCH)
481                        .unwrap_or_default()
482                        .as_millis()
483                ),
484                uri: format!("{node_id}:vector_{i}"),
485                similarity: 0.9 - (i as f32 * 0.1),
486                metadata: Some(HashMap::new()),
487                metrics: HashMap::new(),
488            });
489        }
490
491        Ok(NodeSearchResult {
492            node_id,
493            results,
494            latency_ms: start_time.elapsed().as_millis() as u64,
495            error: None,
496        })
497    }
498
499    /// Merge results from multiple nodes
500    fn merge_node_results(
501        &self,
502        node_results: &[NodeSearchResult],
503        k: usize,
504    ) -> Vec<SimilarityResult> {
505        let mut all_results = Vec::new();
506
507        // Collect all results
508        for node_result in node_results {
509            all_results.extend(node_result.results.clone());
510        }
511
512        // Sort by similarity score (descending)
513        all_results.sort_by(|a, b| b.similarity.partial_cmp(&a.similarity).unwrap());
514
515        // Take top k results
516        all_results.truncate(k);
517        all_results
518    }
519
520    /// Compute hash partition for vector
521    fn compute_hash_partition(&self, vector: &Vector) -> String {
522        let values = vector.as_f32();
523        let mut hash = 0u64;
524        for &value in &values {
525            hash = hash.wrapping_mul(31).wrapping_add(value.to_bits() as u64);
526        }
527        format!("partition_{}", hash % 10) // 10 partitions
528    }
529
530    /// Compute range partition for vector
531    fn compute_range_partition(&self, vector: &Vector) -> String {
532        let values = vector.as_f32();
533        let sum: f32 = values.iter().sum();
534        let partition_id = (sum.abs() % 10.0) as usize;
535        format!("partition_{partition_id}")
536    }
537
538    /// Compute consistent hash partition for vector
539    fn compute_consistent_hash_partition(&self, vector: &Vector) -> String {
540        // Simplified consistent hashing
541        self.compute_hash_partition(vector)
542    }
543
544    /// Get nodes for a specific partition
545    fn get_nodes_for_partition(
546        &self,
547        _partition: &str,
548        nodes: &HashMap<String, DistributedNodeConfig>,
549        _load_balancer: &LoadBalancer,
550    ) -> Result<Vec<String>> {
551        // Simplified implementation - return all healthy nodes
552        Ok(nodes
553            .iter()
554            .filter(|(_, config)| config.health_status == NodeHealthStatus::Healthy)
555            .map(|(id, _)| id.clone())
556            .collect())
557    }
558
559    /// Get cluster statistics
560    pub fn get_cluster_stats(&self) -> DistributedClusterStats {
561        let nodes = self.nodes.read().unwrap();
562
563        let total_nodes = nodes.len();
564        let healthy_nodes = nodes
565            .values()
566            .filter(|config| config.health_status == NodeHealthStatus::Healthy)
567            .count();
568
569        let total_capacity: usize = nodes.values().map(|config| config.capacity).sum();
570        let average_load_factor = if !nodes.is_empty() {
571            nodes.values().map(|config| config.load_factor).sum::<f32>() / nodes.len() as f32
572        } else {
573            0.0
574        };
575
576        DistributedClusterStats {
577            total_nodes,
578            healthy_nodes,
579            total_capacity,
580            average_load_factor,
581            partitioning_strategy: format!("{:?}", self.partitioning_strategy),
582        }
583    }
584}
585
586/// Cluster statistics
587#[derive(Debug, Clone, Serialize, Deserialize)]
588pub struct DistributedClusterStats {
589    pub total_nodes: usize,
590    pub healthy_nodes: usize,
591    pub total_capacity: usize,
592    pub average_load_factor: f32,
593    pub partitioning_strategy: String,
594}
595
596impl LoadBalancer {
597    fn new(algorithm: LoadBalancingAlgorithm) -> Self {
598        Self {
599            algorithm,
600            node_stats: HashMap::new(),
601        }
602    }
603
604    fn add_node(&mut self, node_id: &str) {
605        self.node_stats.insert(
606            node_id.to_string(),
607            NodeStats {
608                active_queries: 0,
609                average_latency_ms: 0.0,
610                success_rate: 1.0,
611                last_updated: SystemTime::now(),
612            },
613        );
614    }
615
616    fn remove_node(&mut self, node_id: &str) {
617        self.node_stats.remove(node_id);
618    }
619}
620
621impl ReplicationManager {
622    fn new() -> Self {
623        Self {
624            partition_replicas: HashMap::new(),
625            consistency_policies: HashMap::new(),
626        }
627    }
628
629    fn add_node(&mut self, node_id: &str, _replication_factor: usize) {
630        // Add node to replication topology
631        debug!("Adding node {} to replication topology", node_id);
632    }
633
634    fn remove_node(&mut self, node_id: &str) {
635        // Remove node from replication topology
636        debug!("Removing node {} from replication topology", node_id);
637    }
638}
639
640impl QueryRouter {
641    fn new(execution_strategy: QueryExecutionStrategy) -> Self {
642        Self {
643            routing_table: Arc::new(RwLock::new(HashMap::new())),
644            execution_strategy,
645        }
646    }
647}
648
649impl HealthMonitor {
650    fn new(check_interval: Duration, check_timeout: Duration) -> Self {
651        Self {
652            check_interval,
653            check_timeout,
654            health_history: HashMap::new(),
655        }
656    }
657
658    fn start_monitoring(&mut self, node_id: &str) {
659        self.health_history.insert(node_id.to_string(), Vec::new());
660        debug!("Started health monitoring for node {}", node_id);
661    }
662
663    fn stop_monitoring(&mut self, node_id: &str) {
664        self.health_history.remove(node_id);
665        debug!("Stopped health monitoring for node {}", node_id);
666    }
667}
668
669#[cfg(test)]
670mod tests {
671    use super::*;
672
673    #[tokio::test]
674    async fn test_distributed_search_creation() {
675        let distributed_search = DistributedVectorSearch::new(PartitioningStrategy::Hash);
676        assert!(distributed_search.is_ok());
677    }
678
679    #[tokio::test]
680    async fn test_node_registration() {
681        let distributed_search = DistributedVectorSearch::new(PartitioningStrategy::Hash).unwrap();
682
683        let config = DistributedNodeConfig {
684            node_id: "node1".to_string(),
685            endpoint: "http://localhost:8080".to_string(),
686            region: "us-west-1".to_string(),
687            capacity: 100000,
688            load_factor: 0.5,
689            latency_ms: 10,
690            health_status: NodeHealthStatus::Healthy,
691            replication_factor: 3,
692        };
693
694        assert!(distributed_search.register_node(config).await.is_ok());
695
696        let stats = distributed_search.get_cluster_stats();
697        assert_eq!(stats.total_nodes, 1);
698        assert_eq!(stats.healthy_nodes, 1);
699    }
700
701    #[tokio::test]
702    async fn test_distributed_query_execution() {
703        let distributed_search = DistributedVectorSearch::new(PartitioningStrategy::Hash).unwrap();
704
705        // Register test nodes
706        for i in 0..3 {
707            let config = DistributedNodeConfig {
708                node_id: format!("node{i}"),
709                endpoint: format!("http://localhost:808{i}"),
710                region: "us-west-1".to_string(),
711                capacity: 100000,
712                load_factor: 0.3,
713                latency_ms: 5 + i * 2,
714                health_status: NodeHealthStatus::Healthy,
715                replication_factor: 2,
716            };
717            distributed_search.register_node(config).await.unwrap();
718        }
719
720        // Create test query
721        let query = DistributedQuery {
722            id: "test_query_1".to_string(),
723            query_vector: crate::Vector::new(vec![1.0, 0.5, 0.8]),
724            k: 10,
725            similarity_metric: SimilarityMetric::Cosine,
726            filters: HashMap::new(),
727            timeout: Duration::from_secs(5),
728            consistency_level: ConsistencyLevel::Quorum,
729        };
730
731        let response = distributed_search.search(query).await.unwrap();
732
733        assert_eq!(response.nodes_queried, 3);
734        assert!(response.nodes_responded > 0);
735        assert!(!response.merged_results.is_empty());
736    }
737}
oxirs_vec/distributed_vector_search.rs

oxirs_vec/
distributed_vector_search.rs
