Request Lifecycle and Data Flow

// Simplified request flow in ServiceManager
SearchResponse ServiceManager::search(const SearchRequest& req) {
  // 1. Validate and parse
  auto index = get_index(req.index_name);
  auto query = parse_vector(req.vector);

  // 2. Find relevant centroids
  auto centroids = index->find_nearest_centroids(query, req.nprobe);

  // 3. Map to nodes
  std::map<NodeId, std::vector<CentroidId>> node_centroids;
  for (auto& c : centroids) {
    auto node = allocator->get_node_for_centroid(c);
    node_centroids[node].push_back(c);
  }

  // 4. Parallel execution
  std::vector<std::future<PartialResult>> futures;
  for (auto& [node, cids] : node_centroids) {
    futures.push_back(std::async([&] {
      return node->search(query, cids, req.k);
    }));
  }

  // 5. Collect and merge
  std::vector<PartialResult> results;
  for (auto& f : futures) {
    results.push_back(f.get());
  }

  return merger->merge(results, req.k);
}