src: dynamic block sync size

Co-authored-by: nahuhh

src/cryptonote_config.h

@@ -98,6 +98,10 @@
 #define BLOCKS_SYNCHRONIZING_DEFAULT_COUNT_PRE_V4       100    //by default, blocks count in blocks downloading
 #define BLOCKS_SYNCHRONIZING_DEFAULT_COUNT              20     //by default, blocks count in blocks downloading
 #define BLOCKS_SYNCHRONIZING_MAX_COUNT                  2048   //must be a power of 2, greater than 128, equal to SEEDHASH_EPOCH_BLOCKS
+#define BLOCKS_MEDIAN_WINDOW                            100      //by default, compute median weights of last 100 blocks
+#define BATCH_MAX_WEIGHT                                20       //by default, maximum size of batch in [mB]
+#define BATCH_MAX_ALLOWED_WEIGHT                        50       //maximum allowed size of batch in [mB]
+#define BLOCKS_HUGE_THRESHOLD_SIZE                      ((BATCH_MAX_WEIGHT * 1000000) / 2) //blocks that we consider huge [B]
 
 #define CRYPTONOTE_MEMPOOL_TX_LIVETIME                    (86400*3) //seconds, three days
 #define CRYPTONOTE_MEMPOOL_TX_FROM_ALT_BLOCK_LIVETIME     604800 //seconds, one week

src/cryptonote_core/blockchain.h

@@ -1445,7 +1445,11 @@ namespace cryptonote
      * @param weights return-by-reference the list of weights
      * @param count the number of blocks to get weights for
      */
+  public:
     void get_last_n_blocks_weights(std::vector<uint64_t>& weights, size_t count) const;
+#ifndef IN_UNIT_TESTS
+  private:
+#endif
 
     /**
      * @brief gets block long term weight median

src/cryptonote_core/cryptonote_core.cpp

@@ -168,6 +168,11 @@ namespace cryptonote
   , "How many blocks to sync at once during chain synchronization (0 = adaptive)."
   , 0
   };
+  static const command_line::arg_descriptor<size_t> arg_batch_max_weight  = {
+    "batch-max-weight"
+    , "How many megabytes to sync in one batch during chain synchronization, default is 20 max"
+  , (BATCH_MAX_WEIGHT)
+  };
   static const command_line::arg_descriptor<std::string> arg_check_updates = {
     "check-updates"
   , "Check for new versions of monero: [disabled|notify|download|update]"
@@ -339,6 +344,7 @@ namespace cryptonote
     command_line::add_arg(desc, arg_fast_block_sync);
     command_line::add_arg(desc, arg_show_time_stats);
     command_line::add_arg(desc, arg_block_sync_size);
+    command_line::add_arg(desc, arg_batch_max_weight);
     command_line::add_arg(desc, arg_check_updates);
     command_line::add_arg(desc, arg_fluffy_blocks);
     command_line::add_arg(desc, arg_no_fluffy_blocks);
@@ -695,6 +701,17 @@ namespace cryptonote
     if (block_sync_size > BLOCKS_SYNCHRONIZING_MAX_COUNT)
       MERROR("Error --block-sync-size cannot be greater than " << BLOCKS_SYNCHRONIZING_MAX_COUNT);
 
+    if(block_sync_size)
+      MWARNING("When --block-sync-size defined, the --batch-max-weight is not going to have any effect.");
+
+    batch_max_weight = command_line::get_arg(vm, arg_batch_max_weight);
+    if (batch_max_weight > BATCH_MAX_ALLOWED_WEIGHT) {
+      MERROR("Error --batch-max-weight cannot be greater than " << BATCH_MAX_ALLOWED_WEIGHT << " [mB]");
+      batch_max_weight = BATCH_MAX_ALLOWED_WEIGHT;
+    }
+
+    batch_max_weight *= 1000000; // transfer it to byte.
+
     MGINFO("Loading checkpoints");
 
     // load json & DNS checkpoints, and verify them
@@ -1218,16 +1235,37 @@ namespace cryptonote
     return true;
   }
   //-----------------------------------------------------------------------------------------------
-  size_t core::get_block_sync_size(uint64_t height) const
+  size_t core::get_block_sync_size(uint64_t height, const uint64_t average_blocksize_of_biggest_batch) const
   {
-    static const uint64_t quick_height = m_nettype == TESTNET ? 801219 : m_nettype == MAINNET ? 1220516 : 0;
     size_t res = 0;
     if (block_sync_size > 0)
       res = block_sync_size;
-    else if (height >= quick_height)
+    else {
-      res = BLOCKS_SYNCHRONIZING_DEFAULT_COUNT;
+      size_t number_of_blocks = BLOCKS_MEDIAN_WINDOW;
-    else
+      std::vector<uint64_t> last_n_blocks_weights;
-      res = BLOCKS_SYNCHRONIZING_DEFAULT_COUNT_PRE_V4;
+      m_blockchain_storage.get_last_n_blocks_weights(last_n_blocks_weights, number_of_blocks);
+      uint64_t median_weight = epee::misc_utils::median(last_n_blocks_weights);
+      MINFO("Last " << number_of_blocks
+             << " blocks median size is " << median_weight
+             << " bytes and the max average blocksize in the queue is " << average_blocksize_of_biggest_batch << " bytes");
+      uint64_t projected_blocksize = (average_blocksize_of_biggest_batch > median_weight) ? average_blocksize_of_biggest_batch : median_weight;
+      if ((projected_blocksize * BLOCKS_MEDIAN_WINDOW) < batch_max_weight) {
+        res = BLOCKS_MEDIAN_WINDOW;
+        MINFO("blocks are tiny, " << projected_blocksize << " bytes, sync " << res << " blocks in next batch");
+      }
+      else if (projected_blocksize >= batch_max_weight) {
+        res = 1;
+        MINFO("blocks are projected to surpass " << batch_max_weight << " bytes, syncing just a single block in next batch");
+      }
+      else if (projected_blocksize > BLOCKS_HUGE_THRESHOLD_SIZE) {
+        res = 1;
+        MINFO("blocks are huge, sync just a single block in next batch");
+      }
+      else {
+        res = batch_max_weight / projected_blocksize;
+        MINFO("projected blocksize is " << projected_blocksize << " bytes, sync " << res << " blocks in next batch");
+      }
+    }
 
     static size_t max_block_size = 0;
     if (max_block_size == 0)

src/cryptonote_core/cryptonote_core.h

@@ -799,9 +799,13 @@ namespace cryptonote
      /**
       * @brief get the number of blocks to sync in one go
       *
+      * @param height the height that we want to get_block_sync_size for
+      * @param average_blocksize_of_biggest_batch is the average blocksize of the biggest batch
+      * we are downloading in current active connections.
+      *
       * @return the number of blocks to sync in one go
       */
-     size_t get_block_sync_size(uint64_t height) const;
+     size_t get_block_sync_size(uint64_t height, const uint64_t average_blocksize_of_biggest_batch = 0) const;
 
      /**
       * @brief get the sum of coinbase tx amounts between blocks
@@ -1136,6 +1140,7 @@ namespace cryptonote
      bool m_disable_dns_checkpoints;
 
      size_t block_sync_size;
+     std::uint64_t batch_max_weight;
 
      time_t start_time;
 

src/cryptonote_protocol/cryptonote_protocol_handler.h

@@ -49,6 +49,7 @@
 #include "net/levin_base.h"
 #include "p2p/net_node_common.h"
 #include <boost/circular_buffer.hpp>
+#include <atomic>
 
 PUSH_WARNINGS
 DISABLE_VS_WARNINGS(4355)
@@ -111,6 +112,15 @@ namespace cryptonote
     void log_connections();
     std::list<connection_info> get_connections();
     const block_queue &get_block_queue() const { return m_block_queue; }
+    const std::uint64_t max_average_of_blocksize_in_queue() {
+      std::vector<std::uint64_t> average_blocksize{0};
+      m_block_queue.foreach([&](const cryptonote::block_queue::span &span) {
+        average_blocksize.push_back(span.size / span.nblocks);
+        return true; // we don't care about the return value
+      });
+      MINFO("Maximum average of blocksize for current batches : " << *std::max_element(average_blocksize.begin(), average_blocksize.end()));
+      return *std::max_element(average_blocksize.begin(), average_blocksize.end());
+    }
     void stop();
     void on_connection_close(cryptonote_connection_context &context);
     void set_max_out_peers(epee::net_utils::zone zone, unsigned int max) { CRITICAL_REGION_LOCAL(m_max_out_peers_lock); m_max_out_peers[zone] = max; }
@@ -190,6 +200,7 @@ namespace cryptonote
     uint64_t m_sync_download_chain_size, m_sync_download_objects_size;
     size_t m_block_download_max_size;
     bool m_sync_pruned_blocks;
+    std::atomic<size_t> m_bss;
 
     // Values for sync time estimates
     boost::posix_time::ptime m_sync_start_time;

src/cryptonote_protocol/cryptonote_protocol_handler.inl

@@ -87,8 +87,8 @@ namespace cryptonote
                                                                                                               m_synchronized(offline),
                                                                                                               m_ask_for_txpool_complement(true),
                                                                                                               m_stopping(false),
-                                                                                                              m_no_sync(false)
+                                                                                                              m_no_sync(false),
-
+                                                                                                              m_bss(0)
   {
     if(!m_p2p)
       m_p2p = &m_p2p_stub;
@@ -2224,7 +2224,7 @@ skip:
       NOTIFY_REQUEST_GET_OBJECTS::request req;
       bool is_next = false;
       size_t count = 0;
-      const size_t count_limit = m_core.get_block_sync_size(m_core.get_current_blockchain_height());
+      size_t l_m_bss = m_bss = m_core.get_block_sync_size(m_core.get_current_blockchain_height(), max_average_of_blocksize_in_queue());
       std::pair<uint64_t, uint64_t> span = std::make_pair(0, 0);
       if (force_next_span)
       {
@@ -2274,7 +2274,7 @@ skip:
         const uint64_t first_block_height = context.m_last_response_height - context.m_needed_objects.size() + 1;
         static const uint64_t bp_fork_height = m_core.get_earliest_ideal_height_for_version(8);
         bool sync_pruned_blocks = m_sync_pruned_blocks && first_block_height >= bp_fork_height && m_core.get_blockchain_pruning_seed();
-        span = m_block_queue.reserve_span(first_block_height, context.m_last_response_height, count_limit, context.m_connection_id, context.m_remote_address, sync_pruned_blocks, m_core.get_blockchain_pruning_seed(), context.m_pruning_seed, context.m_remote_blockchain_height, context.m_needed_objects);
+        span = m_block_queue.reserve_span(first_block_height, context.m_last_response_height, l_m_bss, context.m_connection_id, context.m_remote_address, sync_pruned_blocks, m_core.get_blockchain_pruning_seed(), context.m_pruning_seed, context.m_remote_blockchain_height, context.m_needed_objects);
         MDEBUG(context << " span from " << first_block_height << ": " << span.first << "/" << span.second);
         if (span.second > 0)
         {
@@ -2360,7 +2360,7 @@ skip:
         context.m_expect_height = span.first;
         context.m_expect_response = NOTIFY_RESPONSE_GET_OBJECTS::ID;
         MLOG_P2P_MESSAGE("-->>NOTIFY_REQUEST_GET_OBJECTS: blocks.size()=" << req.blocks.size()
-            << "requested blocks count=" << count << " / " << count_limit << " from " << span.first << ", first hash " << req.blocks.front());
+            << "requested blocks count=" << count << " / " << l_m_bss << " from " << span.first << ", first hash " << req.blocks.front());
         //epee::net_utils::network_throttle_manager::get_global_throttle_inreq().logger_handle_net("log/dr-monero/net/req-all.data", sec, get_avg_block_size());
 
         MDEBUG("Asking for " << (req.prune ? "pruned" : "full") << " data, start/end "

tests/unit_tests/node_server.cpp

@@ -74,7 +74,7 @@ public:
   bool cleanup_handle_incoming_blocks(bool force_sync = false) { return true; }
   bool update_checkpoints(const bool skip_dns = false) { return true; }
   uint64_t get_target_blockchain_height() const { return 1; }
-  size_t get_block_sync_size(uint64_t height) const { return BLOCKS_SYNCHRONIZING_DEFAULT_COUNT; }
+  size_t get_block_sync_size(uint64_t height, const uint64_t average_blocksize_of_biggest_batch = 0) const { return BLOCKS_SYNCHRONIZING_DEFAULT_COUNT; }
   virtual void on_transactions_relayed(epee::span<const cryptonote::blobdata> tx_blobs, cryptonote::relay_method tx_relay) {}
   cryptonote::network_type get_nettype() const { return cryptonote::MAINNET; }
   bool get_pool_transaction(const crypto::hash& id, cryptonote::blobdata& tx_blob, cryptonote::relay_category tx_category) const { return false; }