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
225                .nodes
226                .write()
227                .expect("nodes lock should not be poisoned");
228            info!("Registering node {} at {}", config.node_id, config.endpoint);
229            nodes.insert(config.node_id.clone(), config.clone());
230        } // Drop nodes lock before await
231
232        // Update load balancer
233        let mut load_balancer = self.load_balancer.lock().await;
234        load_balancer.add_node(&config.node_id);
235
236        // Update replication manager
237        let mut replication_manager = self.replication_manager.lock().await;
238        replication_manager.add_node(&config.node_id, config.replication_factor);
239
240        // Start health monitoring for the new node
241        let mut health_monitor = self.health_monitor.lock().await;
242        health_monitor.start_monitoring(&config.node_id);
243
244        Ok(())
245    }
246
247    /// Remove a node from the cluster
248    pub async fn deregister_node(&self, node_id: &str) -> Result<()> {
249        let config = {
250            let mut nodes = self
251                .nodes
252                .write()
253                .expect("nodes lock should not be poisoned");
254            nodes.remove(node_id)
255        }; // Drop nodes lock before await
256
257        if let Some(config) = config {
258            info!("Deregistering node {} at {}", node_id, config.endpoint);
259
260            // Update load balancer
261            let mut load_balancer = self.load_balancer.lock().await;
262            load_balancer.remove_node(node_id);
263
264            // Update replication manager
265            let mut replication_manager = self.replication_manager.lock().await;
266            replication_manager.remove_node(node_id);
267
268            // Stop health monitoring
269            let mut health_monitor = self.health_monitor.lock().await;
270            health_monitor.stop_monitoring(node_id);
271        }
272
273        Ok(())
274    }
275
276    /// Execute distributed vector search
277    pub async fn search(&self, query: DistributedQuery) -> Result<DistributedSearchResponse> {
278        let start_time = Instant::now();
279
280        // Determine target nodes based on query and partitioning strategy
281        let target_nodes = self.select_target_nodes(&query).await?;
282
283        info!(
284            "Executing distributed query {} across {} nodes",
285            query.id,
286            target_nodes.len()
287        );
288
289        // Execute query on selected nodes
290        let node_results = match self.query_router.execution_strategy {
291            QueryExecutionStrategy::Parallel => {
292                self.execute_parallel_query(&query, &target_nodes).await?
293            }
294            QueryExecutionStrategy::Sequential => {
295                self.execute_sequential_query(&query, &target_nodes).await?
296            }
297            QueryExecutionStrategy::Adaptive => {
298                self.execute_adaptive_query(&query, &target_nodes).await?
299            }
300        };
301
302        // Merge results from all nodes
303        let merged_results = self.merge_node_results(&node_results, query.k);
304
305        // Update analytics
306        let analytics = crate::advanced_analytics::QueryAnalytics {
307            query_id: query.id.clone(),
308            timestamp: std::time::SystemTime::now()
309                .duration_since(std::time::UNIX_EPOCH)
310                .unwrap_or_default()
311                .as_secs(),
312            query_vector: query.query_vector.as_f32(),
313            similarity_metric: "distributed".to_string(),
314            top_k: query.k,
315            response_time: start_time.elapsed(),
316            results_count: merged_results.len(),
317            avg_similarity_score: merged_results.iter().map(|r| r.similarity).sum::<f32>()
318                / merged_results.len().max(1) as f32,
319            min_similarity_score: merged_results
320                .iter()
321                .map(|r| r.similarity)
322                .min_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal))
323                .unwrap_or(0.0),
324            max_similarity_score: merged_results
325                .iter()
326                .map(|r| r.similarity)
327                .max_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal))
328                .unwrap_or(0.0),
329            cache_hit: false,
330            index_type: "distributed".to_string(),
331        };
332        let mut analytics_guard = self.analytics.lock().await;
333        analytics_guard.record_query(analytics);
334
335        let nodes_responded = node_results.len();
336        Ok(DistributedSearchResponse {
337            query_id: query.id,
338            merged_results,
339            node_results,
340            total_latency_ms: start_time.elapsed().as_millis() as u64,
341            nodes_queried: target_nodes.len(),
342            nodes_responded,
343        })
344    }
345
346    /// Select target nodes for query execution
347    async fn select_target_nodes(&self, query: &DistributedQuery) -> Result<Vec<String>> {
348        let nodes = self
349            .nodes
350            .read()
351            .expect("nodes lock should not be poisoned")
352            .clone();
353        let load_balancer = self.load_balancer.lock().await;
354
355        match &self.partitioning_strategy {
356            PartitioningStrategy::Hash => {
357                // Hash-based selection
358                let partition = self.compute_hash_partition(&query.query_vector);
359                self.get_nodes_for_partition(&partition, &nodes, &load_balancer)
360            }
361            PartitioningStrategy::Range => {
362                // Range-based selection
363                let partition = self.compute_range_partition(&query.query_vector);
364                self.get_nodes_for_partition(&partition, &nodes, &load_balancer)
365            }
366            PartitioningStrategy::ConsistentHash => {
367                // Consistent hash selection
368                let partition = self.compute_consistent_hash_partition(&query.query_vector);
369                self.get_nodes_for_partition(&partition, &nodes, &load_balancer)
370            }
371            PartitioningStrategy::Geographic => {
372                // Geographic-based selection (use all healthy nodes)
373                Ok(nodes
374                    .iter()
375                    .filter(|(_, config)| config.health_status == NodeHealthStatus::Healthy)
376                    .map(|(id, _)| id.clone())
377                    .collect())
378            }
379            PartitioningStrategy::Custom(_func) => {
380                // Custom partitioning function
381                Ok(nodes.keys().cloned().collect())
382            }
383        }
384    }
385
386    /// Execute query in parallel across nodes
387    async fn execute_parallel_query(
388        &self,
389        query: &DistributedQuery,
390        target_nodes: &[String],
391    ) -> Result<Vec<NodeSearchResult>> {
392        let mut handles = Vec::new();
393
394        for node_id in target_nodes {
395            let node_id = node_id.clone();
396            let query = query.clone();
397            let nodes = Arc::clone(&self.nodes);
398
399            let handle =
400                tokio::spawn(async move { Self::execute_node_query(node_id, query, nodes).await });
401
402            handles.push(handle);
403        }
404
405        let mut results = Vec::new();
406        for handle in handles {
407            match handle.await {
408                Ok(Ok(result)) => results.push(result),
409                Ok(Err(e)) => error!("Node query failed: {}", e),
410                Err(e) => error!("Task join failed: {}", e),
411            }
412        }
413
414        Ok(results)
415    }
416
417    /// Execute query sequentially across nodes
418    async fn execute_sequential_query(
419        &self,
420        query: &DistributedQuery,
421        target_nodes: &[String],
422    ) -> Result<Vec<NodeSearchResult>> {
423        let mut results = Vec::new();
424
425        for node_id in target_nodes {
426            match Self::execute_node_query(node_id.clone(), query.clone(), Arc::clone(&self.nodes))
427                .await
428            {
429                Ok(result) => {
430                    results.push(result);
431                    // Early termination if we have enough results
432                    if results.len() >= query.k {
433                        break;
434                    }
435                }
436                Err(e) => {
437                    error!("Node query failed for {}: {}", node_id, e);
438                    continue;
439                }
440            }
441        }
442
443        Ok(results)
444    }
445
446    /// Execute query with adaptive strategy
447    async fn execute_adaptive_query(
448        &self,
449        query: &DistributedQuery,
450        target_nodes: &[String],
451    ) -> Result<Vec<NodeSearchResult>> {
452        // For demonstration, use parallel for small node counts, sequential for large
453        if target_nodes.len() <= 5 {
454            self.execute_parallel_query(query, target_nodes).await
455        } else {
456            self.execute_sequential_query(query, target_nodes).await
457        }
458    }
459
460    /// Execute query on a specific node
461    async fn execute_node_query(
462        node_id: String,
463        query: DistributedQuery,
464        nodes: Arc<RwLock<HashMap<String, DistributedNodeConfig>>>,
465    ) -> Result<NodeSearchResult> {
466        let start_time = Instant::now();
467
468        // In a real implementation, this would make HTTP requests to the node
469        // For now, simulate the query execution
470
471        {
472            let nodes_guard = nodes.read().expect("nodes lock should not be poisoned");
473            let _node_config = nodes_guard
474                .get(&node_id)
475                .ok_or_else(|| anyhow::anyhow!("Node {} not found", node_id))?;
476        } // Drop the guard here
477
478        // Simulate network latency and processing
479        tokio::time::sleep(Duration::from_millis(10)).await;
480
481        // Generate sample results
482        let mut results = Vec::new();
483        for i in 0..query.k.min(10) {
484            results.push(SimilarityResult {
485                id: format!(
486                    "dist_{}_{}_{}",
487                    node_id,
488                    i,
489                    std::time::SystemTime::now()
490                        .duration_since(std::time::UNIX_EPOCH)
491                        .unwrap_or_default()
492                        .as_millis()
493                ),
494                uri: format!("{node_id}:vector_{i}"),
495                similarity: 0.9 - (i as f32 * 0.1),
496                metadata: Some(HashMap::new()),
497                metrics: HashMap::new(),
498            });
499        }
500
501        Ok(NodeSearchResult {
502            node_id,
503            results,
504            latency_ms: start_time.elapsed().as_millis() as u64,
505            error: None,
506        })
507    }
508
509    /// Merge results from multiple nodes
510    fn merge_node_results(
511        &self,
512        node_results: &[NodeSearchResult],
513        k: usize,
514    ) -> Vec<SimilarityResult> {
515        let mut all_results = Vec::new();
516
517        // Collect all results
518        for node_result in node_results {
519            all_results.extend(node_result.results.clone());
520        }
521
522        // Sort by similarity score (descending)
523        all_results.sort_by(|a, b| {
524            b.similarity
525                .partial_cmp(&a.similarity)
526                .unwrap_or(std::cmp::Ordering::Equal)
527        });
528
529        // Take top k results
530        all_results.truncate(k);
531        all_results
532    }
533
534    /// Compute hash partition for vector
535    fn compute_hash_partition(&self, vector: &Vector) -> String {
536        let values = vector.as_f32();
537        let mut hash = 0u64;
538        for &value in &values {
539            hash = hash.wrapping_mul(31).wrapping_add(value.to_bits() as u64);
540        }
541        format!("partition_{}", hash % 10) // 10 partitions
542    }
543
544    /// Compute range partition for vector
545    fn compute_range_partition(&self, vector: &Vector) -> String {
546        let values = vector.as_f32();
547        let sum: f32 = values.iter().sum();
548        let partition_id = (sum.abs() % 10.0) as usize;
549        format!("partition_{partition_id}")
550    }
551
552    /// Compute consistent hash partition for vector
553    fn compute_consistent_hash_partition(&self, vector: &Vector) -> String {
554        // Simplified consistent hashing
555        self.compute_hash_partition(vector)
556    }
557
558    /// Get nodes for a specific partition
559    fn get_nodes_for_partition(
560        &self,
561        _partition: &str,
562        nodes: &HashMap<String, DistributedNodeConfig>,
563        _load_balancer: &LoadBalancer,
564    ) -> Result<Vec<String>> {
565        // Simplified implementation - return all healthy nodes
566        Ok(nodes
567            .iter()
568            .filter(|(_, config)| config.health_status == NodeHealthStatus::Healthy)
569            .map(|(id, _)| id.clone())
570            .collect())
571    }
572
573    /// Get cluster statistics
574    pub fn get_cluster_stats(&self) -> DistributedClusterStats {
575        let nodes = self
576            .nodes
577            .read()
578            .expect("nodes lock should not be poisoned");
579
580        let total_nodes = nodes.len();
581        let healthy_nodes = nodes
582            .values()
583            .filter(|config| config.health_status == NodeHealthStatus::Healthy)
584            .count();
585
586        let total_capacity: usize = nodes.values().map(|config| config.capacity).sum();
587        let average_load_factor = if !nodes.is_empty() {
588            nodes.values().map(|config| config.load_factor).sum::<f32>() / nodes.len() as f32
589        } else {
590            0.0
591        };
592
593        DistributedClusterStats {
594            total_nodes,
595            healthy_nodes,
596            total_capacity,
597            average_load_factor,
598            partitioning_strategy: format!("{:?}", self.partitioning_strategy),
599        }
600    }
601}
602
603/// Cluster statistics
604#[derive(Debug, Clone, Serialize, Deserialize)]
605pub struct DistributedClusterStats {
606    pub total_nodes: usize,
607    pub healthy_nodes: usize,
608    pub total_capacity: usize,
609    pub average_load_factor: f32,
610    pub partitioning_strategy: String,
611}
612
613impl LoadBalancer {
614    fn new(algorithm: LoadBalancingAlgorithm) -> Self {
615        Self {
616            algorithm,
617            node_stats: HashMap::new(),
618        }
619    }
620
621    fn add_node(&mut self, node_id: &str) {
622        self.node_stats.insert(
623            node_id.to_string(),
624            NodeStats {
625                active_queries: 0,
626                average_latency_ms: 0.0,
627                success_rate: 1.0,
628                last_updated: SystemTime::now(),
629            },
630        );
631    }
632
633    fn remove_node(&mut self, node_id: &str) {
634        self.node_stats.remove(node_id);
635    }
636}
637
638impl ReplicationManager {
639    fn new() -> Self {
640        Self {
641            partition_replicas: HashMap::new(),
642            consistency_policies: HashMap::new(),
643        }
644    }
645
646    fn add_node(&mut self, node_id: &str, _replication_factor: usize) {
647        // Add node to replication topology
648        debug!("Adding node {} to replication topology", node_id);
649    }
650
651    fn remove_node(&mut self, node_id: &str) {
652        // Remove node from replication topology
653        debug!("Removing node {} from replication topology", node_id);
654    }
655}
656
657impl QueryRouter {
658    fn new(execution_strategy: QueryExecutionStrategy) -> Self {
659        Self {
660            routing_table: Arc::new(RwLock::new(HashMap::new())),
661            execution_strategy,
662        }
663    }
664}
665
666impl HealthMonitor {
667    fn new(check_interval: Duration, check_timeout: Duration) -> Self {
668        Self {
669            check_interval,
670            check_timeout,
671            health_history: HashMap::new(),
672        }
673    }
674
675    fn start_monitoring(&mut self, node_id: &str) {
676        self.health_history.insert(node_id.to_string(), Vec::new());
677        debug!("Started health monitoring for node {}", node_id);
678    }
679
680    fn stop_monitoring(&mut self, node_id: &str) {
681        self.health_history.remove(node_id);
682        debug!("Stopped health monitoring for node {}", node_id);
683    }
684}
685
686#[cfg(test)]
687mod tests {
688    use super::*;
689
690    #[tokio::test]
691    async fn test_distributed_search_creation() {
692        let distributed_search = DistributedVectorSearch::new(PartitioningStrategy::Hash);
693        assert!(distributed_search.is_ok());
694    }
695
696    #[tokio::test]
697    async fn test_node_registration() {
698        let distributed_search = DistributedVectorSearch::new(PartitioningStrategy::Hash).unwrap();
699
700        let config = DistributedNodeConfig {
701            node_id: "node1".to_string(),
702            endpoint: "http://localhost:8080".to_string(),
703            region: "us-west-1".to_string(),
704            capacity: 100000,
705            load_factor: 0.5,
706            latency_ms: 10,
707            health_status: NodeHealthStatus::Healthy,
708            replication_factor: 3,
709        };
710
711        assert!(distributed_search.register_node(config).await.is_ok());
712
713        let stats = distributed_search.get_cluster_stats();
714        assert_eq!(stats.total_nodes, 1);
715        assert_eq!(stats.healthy_nodes, 1);
716    }
717
718    #[tokio::test]
719    async fn test_distributed_query_execution() {
720        let distributed_search = DistributedVectorSearch::new(PartitioningStrategy::Hash).unwrap();
721
722        // Register test nodes
723        for i in 0..3 {
724            let config = DistributedNodeConfig {
725                node_id: format!("node{i}"),
726                endpoint: format!("http://localhost:808{i}"),
727                region: "us-west-1".to_string(),
728                capacity: 100000,
729                load_factor: 0.3,
730                latency_ms: 5 + i * 2,
731                health_status: NodeHealthStatus::Healthy,
732                replication_factor: 2,
733            };
734            distributed_search.register_node(config).await.unwrap();
735        }
736
737        // Create test query
738        let query = DistributedQuery {
739            id: "test_query_1".to_string(),
740            query_vector: crate::Vector::new(vec![1.0, 0.5, 0.8]),
741            k: 10,
742            similarity_metric: SimilarityMetric::Cosine,
743            filters: HashMap::new(),
744            timeout: Duration::from_secs(5),
745            consistency_level: ConsistencyLevel::Quorum,
746        };
747
748        let response = distributed_search.search(query).await.unwrap();
749
750        assert_eq!(response.nodes_queried, 3);
751        assert!(response.nodes_responded > 0);
752        assert!(!response.merged_results.is_empty());
753    }
754}
oxirs_vec/distributed_vector_search.rs

oxirs_vec/
distributed_vector_search.rs
