#1934: Add parameter to control minimal retention of historical LB data

src/vt/configs/arguments/app_config.h

@@ -148,6 +148,7 @@ struct AppConfig {
   bool vt_lb_data                = false;
   bool vt_lb_data_compress       = true;
   bool vt_lb_data_in             = false;
+  uint32_t vt_lb_data_retention  = 0;
   std::string vt_lb_data_dir     = "vt_lb_data";
   std::string vt_lb_data_file    = "data.%p.json";
   std::string vt_lb_data_dir_in  = "vt_lb_data_in";
@@ -325,6 +326,7 @@ struct AppConfig {
       | vt_lb_interval
       | vt_lb_data
       | vt_lb_data_compress
+      | vt_lb_data_retention
       | vt_lb_data_dir
       | vt_lb_data_file
       | vt_lb_data_in

src/vt/configs/arguments/args.cc

@@ -911,6 +911,7 @@ void addLbArgs(CLI::App& app, AppConfig& appConfig) {
   auto lb_data      = "Enable load balancing data";
   auto lb_data_in   = "Enable load balancing data input";
   auto lb_data_comp = "Compress load balancing data output with brotli";
+  auto lb_data_hist = "Minimal number of historical LB data phases to retain";
   auto lb_data_dir  = "Load balancing data output directory";
   auto lb_data_file = "Load balancing data output file name";
   auto lb_data_dir_in  = "Load balancing data input directory";
@@ -934,6 +935,7 @@ void addLbArgs(CLI::App& app, AppConfig& appConfig) {
   auto ww = app.add_flag("--vt_lb_data", appConfig.vt_lb_data, lb_data);
   auto za = app.add_flag("--vt_lb_data_in", appConfig.vt_lb_data_in, lb_data_in);
   auto xz = app.add_flag("--vt_lb_data_compress", appConfig.vt_lb_data_compress, lb_data_comp);
+  auto dr = app.add_option("--vt_lb_data_retention", appConfig.vt_lb_data_retention, lb_data_hist);
   auto wx = app.add_option("--vt_lb_data_dir", appConfig.vt_lb_data_dir, lb_data_dir)->capture_default_str();
   auto wy = app.add_option("--vt_lb_data_file", appConfig.vt_lb_data_file, lb_data_file)->capture_default_str();
   auto xx = app.add_option("--vt_lb_data_dir_in", appConfig.vt_lb_data_dir_in, lb_data_dir_in)->capture_default_str();
@@ -967,6 +969,7 @@ void addLbArgs(CLI::App& app, AppConfig& appConfig) {
   xx->group(debugLB);
   xy->group(debugLB);
   xz->group(debugLB);
+  dr->group(debugLB);
   yx->group(debugLB);
   yy->group(debugLB);
   yz->group(debugLB);

src/vt/elm/elm_lb_data.cc

@@ -195,16 +195,20 @@ void ElementLBData::updatePhase(PhaseType const& inc) {
 }
 
 void ElementLBData::resetPhase() {
-  cur_phase_ = fst_lb_phase;
+  // cur_phase_ = fst_lb_phase;
+  // // Resets the current phase in the containers without removing any phase data.
+  // phase_timings_.restartFrom(fst_lb_phase);
+  // subphase_timings_.restartFrom(fst_lb_phase);
+  // phase_comm_.restartFrom(fst_lb_phase);
+  // subphase_comm_.restartFrom(fst_lb_phase);
 }
 
 PhaseType ElementLBData::getPhase() const {
   return cur_phase_;
 }
 
 LoadType ElementLBData::getLoad(PhaseType const& phase) const {
-  auto iter = phase_timings_.find(phase);
-  if (iter != phase_timings_.end()) {
+  if (phase_timings_.contains(phase)) {
     auto const total_load = phase_timings_.at(phase);
 
     vt_debug_print(
@@ -276,13 +280,11 @@ SubphaseType ElementLBData::getSubPhase() const {
   return cur_subphase_;
 }
 
-void ElementLBData::releaseLBDataFromUnneededPhases(PhaseType phase, unsigned int look_back) {
-  if (phase >= look_back) {
-    phase_timings_.erase(phase - look_back);
-    subphase_timings_.erase(phase - look_back);
-    phase_comm_.erase(phase - look_back);
-    subphase_comm_.erase(phase - look_back);
-  }
+void ElementLBData::setHistoryCapacity(unsigned int hist_lb_data_count) {
+  phase_timings_.resize(hist_lb_data_count);
+  subphase_timings_.resize(hist_lb_data_count);
+  phase_comm_.resize(hist_lb_data_count);
+  subphase_comm_.resize(hist_lb_data_count);
 }
 
 std::size_t ElementLBData::getLoadPhaseCount() const {

src/vt/elm/elm_lb_data.h

@@ -47,6 +47,7 @@
 #include "vt/elm/elm_id.h"
 #include "vt/elm/elm_comm.h"
 #include "vt/timing/timing.h"
+#include "vt/utils/container/circular_phases_buffer.h"
 
 namespace vt { namespace vrt { namespace collection { namespace balance {
 
@@ -122,24 +123,23 @@ struct ElementLBData {
   static const constexpr SubphaseType no_subphase =
     std::numeric_limits<SubphaseType>::max();
 
-protected:
   /**
-   * \internal \brief Release LB data from phases prior to lookback
+   * \brief Resize internal buffers
+   *
+   * \param[in] hist_lb_data_count the requested buffers capacity
    */
-  void releaseLBDataFromUnneededPhases(PhaseType phase, unsigned int look_back);
-
-  friend struct vrt::collection::balance::NodeLBData;
+  void setHistoryCapacity(unsigned int hist_lb_data_count);
 
 protected:
   bool cur_time_started_ = false;
   TimeType cur_time_ = TimeType{0.0};
   PhaseType cur_phase_ = fst_lb_phase;
-  std::unordered_map<PhaseType, LoadType> phase_timings_ = {};
-  std::unordered_map<PhaseType, CommMapType> phase_comm_ = {};
+  util::container::CircularPhasesBuffer<LoadType> phase_timings_ = {};
+  util::container::CircularPhasesBuffer<CommMapType> phase_comm_ = {};
 
   SubphaseType cur_subphase_ = 0;
-  std::unordered_map<PhaseType, std::vector<LoadType>> subphase_timings_ = {};
-  std::unordered_map<PhaseType, std::vector<CommMapType>> subphase_comm_ = {};
+  util::container::CircularPhasesBuffer<std::vector<LoadType>> subphase_timings_ = {};
+  util::container::CircularPhasesBuffer<std::vector<CommMapType>> subphase_comm_ = {};
 };
 
 }} /* end namespace vt::elm */