Fee changes from ArticMine

https://github.com/ArticMine/Monero-Documents/blob/master/MoneroScaling2021-02.pdf

with a change to use 1.7 instead of 2.0 for the max long term increase rate

12 files changed, 306 insertions, 44 deletions

diff --git a/src/cryptonote_basic/cryptonote_format_utils.cpp b/src/cryptonote_basic/cryptonote_format_utils.cpp
index 1bc6b6377..d8f9bb176 100644
--- a/src/cryptonote_basic/cryptonote_format_utils.cpp
+++ b/src/cryptonote_basic/cryptonote_format_utils.cpp
@@ -1064,6 +1064,69 @@ namespace cryptonote
     return s;
   }
   //---------------------------------------------------------------
+  uint64_t round_money_up(uint64_t amount, unsigned significant_digits)
+  {
+    // round monetary amount up with the requested amount of significant digits
+
+    CHECK_AND_ASSERT_THROW_MES(significant_digits > 0, "significant_digits must not be 0");
+    static_assert(sizeof(unsigned long long) == sizeof(uint64_t), "Unexpected unsigned long long size");
+
+    // we don't need speed, so we do it via text, as it's easier to get right
+    char buf[32];
+    snprintf(buf, sizeof(buf), "%llu", (unsigned long long)amount);
+    const size_t len = strlen(buf);
+    if (len > significant_digits)
+    {
+      bool bump = false;
+      char *ptr;
+      for (ptr = buf + significant_digits; *ptr; ++ptr)
+      {
+        // bump digits by one if the following digits past significant digits were to be 5 or more
+        if (*ptr != '0')
+        {
+          bump = true;
+          *ptr = '0';
+        }
+      }
+      ptr = buf + significant_digits;
+      while (bump && ptr > buf)
+      {
+        --ptr;
+        // bumping a nine overflows
+        if (*ptr == '9')
+          *ptr = '0';
+        else
+        {
+          // bumping another digit means we can stop bumping (no carry)
+          ++*ptr;
+          bump = false;
+        }
+      }
+      if (bump)
+      {
+        // carry reached the highest digit, we need to add a 1 in front
+        size_t offset = strlen(buf);
+        for (size_t i = offset + 1; i > 0; --i)
+          buf[i] = buf[i - 1];
+        buf[0] = '1';
+      }
+    }
+    char *end = NULL;
+    errno = 0;
+    const unsigned long long ull = strtoull(buf, &end, 10);
+    CHECK_AND_ASSERT_THROW_MES(ull != ULONG_MAX || errno == 0, "Failed to parse rounded amount: " << buf);
+    CHECK_AND_ASSERT_THROW_MES(ull != 0 || amount == 0, "Overflow in rounding");
+    return ull;
+  }
+  //---------------------------------------------------------------
+  std::string round_money_up(const std::string &s, unsigned significant_digits)
+  {
+    uint64_t amount;
+    CHECK_AND_ASSERT_THROW_MES(parse_amount(amount, s), "Failed to parse amount: " << s);
+    amount = round_money_up(amount, significant_digits);
+    return print_money(amount);
+  }
+  //---------------------------------------------------------------
   crypto::hash get_blob_hash(const blobdata& blob)
   {
     crypto::hash h = null_hash;
diff --git a/src/cryptonote_basic/cryptonote_format_utils.h b/src/cryptonote_basic/cryptonote_format_utils.h
index 25cd89e99..ce3ce7492 100644
--- a/src/cryptonote_basic/cryptonote_format_utils.h
+++ b/src/cryptonote_basic/cryptonote_format_utils.h
@@ -144,6 +144,8 @@ namespace cryptonote
   std::string get_unit(unsigned int decimal_point = -1);
   std::string print_money(uint64_t amount, unsigned int decimal_point = -1);
   std::string print_money(const boost::multiprecision::uint128_t &amount, unsigned int decimal_point = -1);
+  uint64_t round_money_up(uint64_t amount, unsigned significant_digits);
+  std::string round_money_up(const std::string &amount, unsigned significant_digits);
   //---------------------------------------------------------------
   template<class t_object>
   bool t_serializable_object_from_blob(t_object& to, const blobdata& b_blob)
diff --git a/src/cryptonote_config.h b/src/cryptonote_config.h
index 5aee87897..8621e1696 100644
--- a/src/cryptonote_config.h
+++ b/src/cryptonote_config.h
@@ -183,8 +183,10 @@
 #define HF_VERSION_CLSAG                        13
 #define HF_VERSION_DETERMINISTIC_UNLOCK_TIME    13
 #define HF_VERSION_BULLETPROOF_PLUS             15
+#define HF_VERSION_2021_SCALING                 15
 
 #define PER_KB_FEE_QUANTIZATION_DECIMALS        8
+#define CRYPTONOTE_SCALING_2021_FEE_ROUNDING_PLACES 2
 
 #define HASH_OF_HASHES_STEP                     512
 
diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 4eaca039c..5f9db676c 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -3710,11 +3710,24 @@ uint64_t Blockchain::get_dynamic_base_fee(uint64_t block_reward, size_t median_b
   if (version >= HF_VERSION_PER_BYTE_FEE)
   {
     lo = mul128(block_reward, DYNAMIC_FEE_REFERENCE_TRANSACTION_WEIGHT, &hi);
-    div128_64(hi, lo, min_block_weight, &hi, &lo, NULL, NULL);
     div128_64(hi, lo, median_block_weight, &hi, &lo, NULL, NULL);
-    assert(hi == 0);
-    lo /= 5;
-    return lo;
+    if (version >= HF_VERSION_2021_SCALING)
+    {
+      // min_fee_per_byte = round_up( 0.95 * block_reward * ref_weight / (fee_median^2) )
+      // note: since hardfork HF_VERSION_2021_SCALING, fee_median (a.k.a. median_block_weight) equals effective long term median
+      div128_64(hi, lo, median_block_weight, &hi, &lo, NULL, NULL);
+      assert(hi == 0);
+      lo -= lo / 20;
+      return lo;
+    }
+    else
+    {
+      // min_fee_per_byte = 0.2 * block_reward * ref_weight / (min_penalty_free_zone * fee_median)
+      div128_64(hi, lo, min_block_weight, &hi, &lo, NULL, NULL);
+      assert(hi == 0);
+      lo /= 5;
+      return lo;
+    }
   }
 
   const uint64_t fee_base = version >= 5 ? DYNAMIC_FEE_PER_KB_BASE_FEE_V5 : DYNAMIC_FEE_PER_KB_BASE_FEE;
@@ -3787,6 +3800,81 @@ bool Blockchain::check_fee(size_t tx_weight, uint64_t fee) const
 }
 
 //------------------------------------------------------------------
+void Blockchain::get_dynamic_base_fee_estimate_2021_scaling(uint64_t grace_blocks, uint64_t base_reward, uint64_t Mnw, uint64_t Mlw, std::vector<uint64_t> &fees) const
+{
+  // variable names and calculations as per https://github.com/ArticMine/Monero-Documents/blob/master/MoneroScaling2021-02.pdf
+  // from (earlier than) this fork, the base fee is per byte
+  const uint64_t Mfw = std::min(Mnw, Mlw);
+
+  // 3 kB divided by something ? It's going to be either 0 or *very* quantized, so fold it into integer steps below
+  //const uint64_t Brlw = DYNAMIC_FEE_REFERENCE_TRANSACTION_WEIGHT / Mfw;
+
+  // constant.... equal to 0, unless floating point, so fold it into integer steps below
+  //const uint64_t Br = DYNAMIC_FEE_REFERENCE_TRANSACTION_WEIGHT / CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5
+
+  //const uint64_t Fl = base_reward * Brlw / Mfw; fold Brlw from above
+  const uint64_t Fl = base_reward * /*Brlw*/ DYNAMIC_FEE_REFERENCE_TRANSACTION_WEIGHT / (Mfw * Mfw);
+
+  // fold Fl into this for better precision (and to match the test cases in the PDF)
+  // const uint64_t Fn = 4 * Fl;
+  const uint64_t Fn = 4 * base_reward * /*Brlw*/ DYNAMIC_FEE_REFERENCE_TRANSACTION_WEIGHT / (Mfw * Mfw);
+
+  // const uint64_t Fm = 16 * base_reward * Br / Mfw; fold Br from above
+  const uint64_t Fm = 16 * base_reward * DYNAMIC_FEE_REFERENCE_TRANSACTION_WEIGHT / (CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 * Mfw);
+
+  // const uint64_t Fp = 2 * base_reward / Mnw;
+
+  // fold Br from above, move 4Fm in the max to decrease quantization effect
+  //const uint64_t Fh = 4 * Fm * std::max<uint64_t>(1, Mfw / (32 * DYNAMIC_FEE_REFERENCE_TRANSACTION_WEIGHT * Mnw / CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5));
+  const uint64_t Fh = std::max<uint64_t>(4 * Fm, 4 * Fm * Mfw / (32 * DYNAMIC_FEE_REFERENCE_TRANSACTION_WEIGHT * Mnw / CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5));
+
+  fees.resize(4);
+  fees[0] = cryptonote::round_money_up(Fl, CRYPTONOTE_SCALING_2021_FEE_ROUNDING_PLACES);
+  fees[1] = cryptonote::round_money_up(Fn, CRYPTONOTE_SCALING_2021_FEE_ROUNDING_PLACES);
+  fees[2] = cryptonote::round_money_up(Fm, CRYPTONOTE_SCALING_2021_FEE_ROUNDING_PLACES);
+  fees[3] = cryptonote::round_money_up(Fh, CRYPTONOTE_SCALING_2021_FEE_ROUNDING_PLACES);
+}
+
+void Blockchain::get_dynamic_base_fee_estimate_2021_scaling(uint64_t grace_blocks, std::vector<uint64_t> &fees) const
+{
+  const uint8_t version = get_current_hard_fork_version();
+  const uint64_t db_height = m_db->height();
+
+  // we want Mlw = median of max((min(Mbw, 1.7 * Ml), Zm), Ml / 1.7)
+  // Mbw: block weight for the last 99990 blocks, 0 for the next 10
+  // Ml: penalty free zone (dynamic), aka long_term_median, aka median of max((min(Mb, 1.7 * Ml), Zm), Ml / 1.7)
+  // Zm: 300000 (minimum penalty free zone)
+  //
+  // So we copy the current rolling median state, add 10 (grace_blocks) zeroes to it, and get back Mlw
+
+  epee::misc_utils::rolling_median_t<uint64_t> rm = m_long_term_block_weights_cache_rolling_median;
+  for (size_t i = 0; i < grace_blocks; ++i)
+    rm.insert(0);
+  const uint64_t Mlw_penalty_free_zone_for_wallet = std::max<uint64_t>(rm.median(), CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5);
+
+  // Msw: median over [100 - grace blocks] past + [grace blocks] future blocks
+  CHECK_AND_ASSERT_THROW_MES(grace_blocks <= 100, "Grace blocks invalid In 2021 fee scaling estimate.");
+  std::vector<uint64_t> weights;
+  get_last_n_blocks_weights(weights, 100 - grace_blocks);
+  weights.reserve(100);
+  for (size_t i = 0; i < grace_blocks; ++i)
+    weights.push_back(0);
+  const uint64_t Msw_effective_short_term_median = std::max(epee::misc_utils::median(weights), Mlw_penalty_free_zone_for_wallet);
+
+  const uint64_t Mnw = std::min(Msw_effective_short_term_median, 50 * Mlw_penalty_free_zone_for_wallet);
+
+  uint64_t already_generated_coins = db_height ? m_db->get_block_already_generated_coins(db_height - 1) : 0;
+  uint64_t base_reward;
+  if (!get_block_reward(m_current_block_cumul_weight_limit / 2, 1, already_generated_coins, base_reward, version))
+  {
+    MERROR("Failed to determine block reward, using placeholder " << print_money(BLOCK_REWARD_OVERESTIMATE) << " as a high bound");
+    base_reward = BLOCK_REWARD_OVERESTIMATE;
+  }
+
+  get_dynamic_base_fee_estimate_2021_scaling(grace_blocks, base_reward, Mnw, Mlw_penalty_free_zone_for_wallet, fees);
+}
+
+//------------------------------------------------------------------
 uint64_t Blockchain::get_dynamic_base_fee_estimate(uint64_t grace_blocks) const
 {
   const uint8_t version = get_current_hard_fork_version();
@@ -3798,6 +3886,13 @@ uint64_t Blockchain::get_dynamic_base_fee_estimate(uint64_t grace_blocks) const
   if (grace_blocks >= CRYPTONOTE_REWARD_BLOCKS_WINDOW)
     grace_blocks = CRYPTONOTE_REWARD_BLOCKS_WINDOW - 1;
 
+  if (version >= HF_VERSION_2021_SCALING)
+  {
+    std::vector<uint64_t> fees;
+    get_dynamic_base_fee_estimate_2021_scaling(grace_blocks, fees);
+    return fees[0];
+  }
+
   const uint64_t min_block_weight = get_min_block_weight(version);
   std::vector<uint64_t> weights;
   get_last_n_blocks_weights(weights, CRYPTONOTE_REWARD_BLOCKS_WINDOW - grace_blocks);
@@ -4472,6 +4567,7 @@ bool Blockchain::check_blockchain_pruning()
   return m_db->check_pruning();
 }
 //------------------------------------------------------------------
+// returns min(Mb, 1.7*Ml) as per https://github.com/ArticMine/Monero-Documents/blob/master/MoneroScaling2021-02.pdf from HF_VERSION_LONG_TERM_BLOCK_WEIGHT
 uint64_t Blockchain::get_next_long_term_block_weight(uint64_t block_weight) const
 {
   PERF_TIMER(get_next_long_term_block_weight);
@@ -4486,7 +4582,18 @@ uint64_t Blockchain::get_next_long_term_block_weight(uint64_t block_weight) cons
   uint64_t long_term_median = get_long_term_block_weight_median(db_height - nblocks, nblocks);
   uint64_t long_term_effective_median_block_weight = std::max<uint64_t>(CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5, long_term_median);
 
-  uint64_t short_term_constraint = long_term_effective_median_block_weight + long_term_effective_median_block_weight * 2 / 5;
+  uint64_t short_term_constraint;
+  if (hf_version >= HF_VERSION_2021_SCALING)
+  {
+    // long_term_block_weight = block_weight bounded to range [long-term-median/1.7, long-term-median*1.7]
+    block_weight = std::max<uint64_t>(block_weight, long_term_effective_median_block_weight * 10 / 17);
+    short_term_constraint = long_term_effective_median_block_weight + long_term_effective_median_block_weight * 7 / 10;
+  }
+  else
+  {
+    // long_term_block_weight = block_weight bounded to range [0, long-term-median*1.4]
+    short_term_constraint = long_term_effective_median_block_weight + long_term_effective_median_block_weight * 2 / 5;
+  }
   uint64_t long_term_block_weight = std::min<uint64_t>(block_weight, short_term_constraint);
 
   return long_term_block_weight;
@@ -4528,7 +4635,11 @@ bool Blockchain::update_next_cumulative_weight_limit(uint64_t *long_term_effecti
 
     m_long_term_effective_median_block_weight = std::max<uint64_t>(CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5, long_term_median);
 
-    uint64_t short_term_constraint = m_long_term_effective_median_block_weight + m_long_term_effective_median_block_weight * 2 / 5;
+    uint64_t short_term_constraint = m_long_term_effective_median_block_weight;
+    if (hf_version >= HF_VERSION_2021_SCALING)
+      short_term_constraint += m_long_term_effective_median_block_weight * 7 / 10;
+    else
+      short_term_constraint += m_long_term_effective_median_block_weight * 2 / 5;
     uint64_t long_term_block_weight = std::min<uint64_t>(block_weight, short_term_constraint);
 
     if (db_height == 1)
@@ -4547,7 +4658,19 @@ bool Blockchain::update_next_cumulative_weight_limit(uint64_t *long_term_effecti
     get_last_n_blocks_weights(weights, CRYPTONOTE_REWARD_BLOCKS_WINDOW);
 
     uint64_t short_term_median = epee::misc_utils::median(weights);
-    uint64_t effective_median_block_weight = std::min<uint64_t>(std::max<uint64_t>(CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5, short_term_median), CRYPTONOTE_SHORT_TERM_BLOCK_WEIGHT_SURGE_FACTOR * m_long_term_effective_median_block_weight);
+    uint64_t effective_median_block_weight;
+    if (hf_version >= HF_VERSION_2021_SCALING)
+    {
+      // effective median = short_term_median bounded to range [long_term_median, 50*long_term_median], but it can't be smaller than the
+      // minimum penalty free zone (a.k.a. 'full reward zone')
+      effective_median_block_weight = std::min<uint64_t>(std::max<uint64_t>(m_long_term_effective_median_block_weight, short_term_median), CRYPTONOTE_SHORT_TERM_BLOCK_WEIGHT_SURGE_FACTOR * m_long_term_effective_median_block_weight);
+    }
+    else
+    {
+      // effective median = short_term_median bounded to range [0, 50*long_term_median], but it can't be smaller than the
+      // minimum penalty free zone (a.k.a. 'full reward zone')
+      effective_median_block_weight = std::min<uint64_t>(std::max<uint64_t>(CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5, short_term_median), CRYPTONOTE_SHORT_TERM_BLOCK_WEIGHT_SURGE_FACTOR * m_long_term_effective_median_block_weight);
+    }
 
     m_current_block_cumul_weight_median = effective_median_block_weight;
   }
diff --git a/src/cryptonote_core/blockchain.h b/src/cryptonote_core/blockchain.h
index 5460d7761..7a94f6358 100644
--- a/src/cryptonote_core/blockchain.h
+++ b/src/cryptonote_core/blockchain.h
@@ -648,6 +648,22 @@ namespace cryptonote
      * @return the fee estimate
      */
     uint64_t get_dynamic_base_fee_estimate(uint64_t grace_blocks) const;
+    void get_dynamic_base_fee_estimate_2021_scaling(uint64_t grace_blocks, uint64_t base_reward, uint64_t Mnw, uint64_t Mlw, std::vector<uint64_t> &fees) const;
+
+    /**
+     * @brief get four levels of dynamic per byte fee estimate for the next few blocks
+     *
+     * The dynamic fee is based on the block weight in a past window, and
+     * the current block reward. It is expressed per byte, and is based on
+     * https://github.com/ArticMine/Monero-Documents/blob/master/MoneroScaling2021-02.pdf
+     * This function calculates an estimate for a dynamic fee which will be
+     * valid for the next grace_blocks
+     *
+     * @param grace_blocks number of blocks we want the fee to be valid for
+     *
+     * @return the fee estimates (4 of them)
+     */
+    void get_dynamic_base_fee_estimate_2021_scaling(uint64_t grace_blocks, std::vector<uint64_t> &fees) const;
 
     /**
      * @brief validate a transaction's fee
diff --git a/src/rpc/core_rpc_server.cpp b/src/rpc/core_rpc_server.cpp
index d23d5cddb..b28583e37 100644
--- a/src/rpc/core_rpc_server.cpp
+++ b/src/rpc/core_rpc_server.cpp
@@ -2890,7 +2890,17 @@ namespace cryptonote
       return r;
 
     CHECK_PAYMENT(req, res, COST_PER_FEE_ESTIMATE);
-    res.fee = m_core.get_blockchain_storage().get_dynamic_base_fee_estimate(req.grace_blocks);
+
+    const uint8_t version = m_core.get_blockchain_storage().get_current_hard_fork_version();
+    if (version >= HF_VERSION_2021_SCALING)
+    {
+      m_core.get_blockchain_storage().get_dynamic_base_fee_estimate_2021_scaling(req.grace_blocks, res.fees);
+      res.fee = res.fees[0];
+    }
+    else
+    {
+      res.fee = m_core.get_blockchain_storage().get_dynamic_base_fee_estimate(req.grace_blocks);
+    }
     res.quantization_mask = Blockchain::get_fee_quantization_mask();
     res.status = CORE_RPC_STATUS_OK;
     return true;
diff --git a/src/rpc/core_rpc_server_commands_defs.h b/src/rpc/core_rpc_server_commands_defs.h
index 9206b5e21..1be2610ff 100644
--- a/src/rpc/core_rpc_server_commands_defs.h
+++ b/src/rpc/core_rpc_server_commands_defs.h
@@ -2191,11 +2191,13 @@ namespace cryptonote
     {
       uint64_t fee;
       uint64_t quantization_mask;
+      std::vector<uint64_t> fees;
 
       BEGIN_KV_SERIALIZE_MAP()
         KV_SERIALIZE_PARENT(rpc_access_response_base)
         KV_SERIALIZE(fee)
         KV_SERIALIZE_OPT(quantization_mask, (uint64_t)1)
+        KV_SERIALIZE(fees)
       END_KV_SERIALIZE_MAP()
     };
     typedef epee::misc_utils::struct_init<response_t> response;
diff --git a/src/wallet/api/wallet.cpp b/src/wallet/api/wallet.cpp
index 014aed0e7..c824e2d95 100644
--- a/src/wallet/api/wallet.cpp
+++ b/src/wallet/api/wallet.cpp
@@ -1744,7 +1744,6 @@ uint64_t WalletImpl::estimateTransactionFee(const std::vector<std::pair<std::str
         m_wallet->use_fork_rules(HF_VERSION_CLSAG, 0),
         m_wallet->use_fork_rules(HF_VERSION_BULLETPROOF_PLUS, 0),
         m_wallet->get_base_fee(),
-        m_wallet->get_fee_multiplier(m_wallet->adjust_priority(static_cast<uint32_t>(priority))),
         m_wallet->get_fee_quantization_mask());
 }
 
diff --git a/src/wallet/node_rpc_proxy.cpp b/src/wallet/node_rpc_proxy.cpp
index 7635c5646..7810abdd2 100644
--- a/src/wallet/node_rpc_proxy.cpp
+++ b/src/wallet/node_rpc_proxy.cpp
@@ -70,6 +70,7 @@ void NodeRPCProxy::invalidate()
   m_dynamic_base_fee_estimate = 0;
   m_dynamic_base_fee_estimate_cached_height = 0;
   m_dynamic_base_fee_estimate_grace_blocks = 0;
+  m_dynamic_base_fee_estimate_vector.clear();
   m_fee_quantization_mask = 1;
   m_rpc_version = 0;
   m_target_height = 0;
@@ -210,7 +211,7 @@ boost::optional<std::string> NodeRPCProxy::get_earliest_height(uint8_t version,
   return boost::optional<std::string>();
 }
 
-boost::optional<std::string> NodeRPCProxy::get_dynamic_base_fee_estimate(uint64_t grace_blocks, uint64_t &fee)
+boost::optional<std::string> NodeRPCProxy::get_dynamic_base_fee_estimate_2021_scaling(uint64_t grace_blocks, std::vector<uint64_t> &fees)
 {
   uint64_t height;
 
@@ -238,13 +239,24 @@ boost::optional<std::string> NodeRPCProxy::get_dynamic_base_fee_estimate(uint64_
     m_dynamic_base_fee_estimate = resp_t.fee;
     m_dynamic_base_fee_estimate_cached_height = height;
     m_dynamic_base_fee_estimate_grace_blocks = grace_blocks;
+    m_dynamic_base_fee_estimate_vector = !resp_t.fees.empty() ? std::move(resp_t.fees) : std::vector<uint64_t>{m_dynamic_base_fee_estimate};
     m_fee_quantization_mask = resp_t.quantization_mask;
   }
 
-  fee = m_dynamic_base_fee_estimate;
+  fees = m_dynamic_base_fee_estimate_vector;
   return boost::optional<std::string>();
 }
 
+boost::optional<std::string> NodeRPCProxy::get_dynamic_base_fee_estimate(uint64_t grace_blocks, uint64_t &fee)
+{
+  std::vector<uint64_t> fees;
+  auto res = get_dynamic_base_fee_estimate_2021_scaling(grace_blocks, fees);
+  if (res)
+    return res;
+  fee = fees[0];
+  return boost::none;
+}
+
 boost::optional<std::string> NodeRPCProxy::get_fee_quantization_mask(uint64_t &fee_quantization_mask)
 {
   uint64_t height;
diff --git a/src/wallet/node_rpc_proxy.h b/src/wallet/node_rpc_proxy.h
index 20f4263a6..07675cdb0 100644
--- a/src/wallet/node_rpc_proxy.h
+++ b/src/wallet/node_rpc_proxy.h
@@ -56,6 +56,7 @@ public:
   boost::optional<std::string> get_adjusted_time(uint64_t &adjusted_time);
   boost::optional<std::string> get_earliest_height(uint8_t version, uint64_t &earliest_height);
   boost::optional<std::string> get_dynamic_base_fee_estimate(uint64_t grace_blocks, uint64_t &fee);
+  boost::optional<std::string> get_dynamic_base_fee_estimate_2021_scaling(uint64_t grace_blocks, std::vector<uint64_t> &fees);
   boost::optional<std::string> get_fee_quantization_mask(uint64_t &fee_quantization_mask);
   boost::optional<std::string> get_rpc_payment_info(bool mining, bool &payment_required, uint64_t &credits, uint64_t &diff, uint64_t &credits_per_hash_found, cryptonote::blobdata &blob, uint64_t &height, uint64_t &seed_height, crypto::hash &seed_hash, crypto::hash &next_seed_hash, uint32_t &cookie);
 
@@ -85,6 +86,7 @@ private:
   uint64_t m_dynamic_base_fee_estimate;
   uint64_t m_dynamic_base_fee_estimate_cached_height;
   uint64_t m_dynamic_base_fee_estimate_grace_blocks;
+  std::vector<uint64_t> m_dynamic_base_fee_estimate_vector;
   uint64_t m_fee_quantization_mask;
   uint64_t m_adjusted_time;
   uint32_t m_rpc_version;
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index a53a1b615..7b97a44d5 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -290,15 +290,15 @@ void do_prepare_file_names(const std::string& file_path, std::string& keys_file,
   mms_file = file_path + ".mms";
 }
 
-uint64_t calculate_fee(uint64_t fee_per_kb, size_t bytes, uint64_t fee_multiplier)
+uint64_t calculate_fee(uint64_t fee_per_kb, size_t bytes)
 {
   uint64_t kB = (bytes + 1023) / 1024;
-  return kB * fee_per_kb * fee_multiplier;
+  return kB * fee_per_kb;
 }
 
-uint64_t calculate_fee_from_weight(uint64_t base_fee, uint64_t weight, uint64_t fee_multiplier, uint64_t fee_quantization_mask)
+uint64_t calculate_fee_from_weight(uint64_t base_fee, uint64_t weight, uint64_t fee_quantization_mask)
 {
-  uint64_t fee = weight * base_fee * fee_multiplier;
+  uint64_t fee = weight * base_fee;
   fee = (fee + fee_quantization_mask - 1) / fee_quantization_mask * fee_quantization_mask;
   return fee;
 }
@@ -878,12 +878,12 @@ uint8_t get_clsag_fork()
   return HF_VERSION_CLSAG;
 }
 
-uint64_t calculate_fee(bool use_per_byte_fee, const cryptonote::transaction &tx, size_t blob_size, uint64_t base_fee, uint64_t fee_multiplier, uint64_t fee_quantization_mask)
+uint64_t calculate_fee(bool use_per_byte_fee, const cryptonote::transaction &tx, size_t blob_size, uint64_t base_fee, uint64_t fee_quantization_mask)
 {
   if (use_per_byte_fee)
-    return calculate_fee_from_weight(base_fee, cryptonote::get_transaction_weight(tx, blob_size), fee_multiplier, fee_quantization_mask);
+    return calculate_fee_from_weight(base_fee, cryptonote::get_transaction_weight(tx, blob_size), fee_quantization_mask);
   else
-    return calculate_fee(base_fee, blob_size, fee_multiplier);
+    return calculate_fee(base_fee, blob_size);
 }
 
 bool get_short_payment_id(crypto::hash8 &payment_id8, const tools::wallet2::pending_tx &ptx, hw::device &hwdev)
@@ -7232,17 +7232,17 @@ bool wallet2::sign_multisig_tx_from_file(const std::string &filename, std::vecto
   return sign_multisig_tx_to_file(exported_txs, filename, txids);
 }
 //----------------------------------------------------------------------------------------------------
-uint64_t wallet2::estimate_fee(bool use_per_byte_fee, bool use_rct, int n_inputs, int mixin, int n_outputs, size_t extra_size, bool bulletproof, bool clsag, bool bulletproof_plus, uint64_t base_fee, uint64_t fee_multiplier, uint64_t fee_quantization_mask) const
+uint64_t wallet2::estimate_fee(bool use_per_byte_fee, bool use_rct, int n_inputs, int mixin, int n_outputs, size_t extra_size, bool bulletproof, bool clsag, bool bulletproof_plus, uint64_t base_fee, uint64_t fee_quantization_mask) const
 {
   if (use_per_byte_fee)
   {
     const size_t estimated_tx_weight = estimate_tx_weight(use_rct, n_inputs, mixin, n_outputs, extra_size, bulletproof, clsag, bulletproof_plus);
-    return calculate_fee_from_weight(base_fee, estimated_tx_weight, fee_multiplier, fee_quantization_mask);
+    return calculate_fee_from_weight(base_fee, estimated_tx_weight, fee_quantization_mask);
   }
   else
   {
     const size_t estimated_tx_size = estimate_tx_size(use_rct, n_inputs, mixin, n_outputs, extra_size, bulletproof, clsag, bulletproof_plus);
-    return calculate_fee(base_fee, estimated_tx_size, fee_multiplier);
+    return calculate_fee(base_fee, estimated_tx_size);
   }
 }
 
@@ -7315,6 +7315,40 @@ uint64_t wallet2::get_base_fee()
   return get_dynamic_base_fee_estimate();
 }
 //----------------------------------------------------------------------------------------------------
+uint64_t wallet2::get_base_fee(uint32_t priority)
+{
+  const bool use_2021_scaling = use_fork_rules(HF_VERSION_2021_SCALING, -30 * 1);
+  if (use_2021_scaling)
+  {
+    // clamp and map to 0..3 indices, mapping 0 (default, but should not end up here) to 0, and 1..4 to 0..3
+    if (priority == 0)
+      priority = 1;
+    else if (priority > 4)
+      priority = 4;
+    --priority;
+
+    std::vector<uint64_t> fees;
+    boost::optional<std::string> result = m_node_rpc_proxy.get_dynamic_base_fee_estimate_2021_scaling(FEE_ESTIMATE_GRACE_BLOCKS, fees);
+    if (result)
+    {
+      MERROR("Failed to determine base fee, using default");
+      return FEE_PER_BYTE;
+    }
+    if (priority >= fees.size())
+    {
+      MERROR("Failed to determine base fee for priority " << priority << ", using default");
+      return FEE_PER_BYTE;
+    }
+    return fees[priority];
+  }
+  else
+  {
+    const uint64_t base_fee = get_base_fee();
+    const uint64_t fee_multiplier = get_fee_multiplier(priority);
+    return base_fee * fee_multiplier;
+  }
+}
+//----------------------------------------------------------------------------------------------------
 uint64_t wallet2::get_fee_quantization_mask()
 {
   if(m_light_wallet)
@@ -7389,9 +7423,8 @@ uint32_t wallet2::adjust_priority(uint32_t priority)
     {
       // check if there's a backlog in the tx pool
       const bool use_per_byte_fee = use_fork_rules(HF_VERSION_PER_BYTE_FEE, 0);
-      const uint64_t base_fee = get_base_fee();
-      const uint64_t fee_multiplier = get_fee_multiplier(1);
-      const double fee_level = fee_multiplier * base_fee * (use_per_byte_fee ? 1 : (12/(double)13 / (double)1024));
+      const uint64_t base_fee = get_base_fee(1);
+      const double fee_level = base_fee * (use_per_byte_fee ? 1 : (12/(double)13 / (double)1024));
       const std::vector<std::pair<uint64_t, uint64_t>> blocks = estimate_backlog({std::make_pair(fee_level, fee_level)});
       if (blocks.size() != 1)
       {
@@ -9665,8 +9698,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
     bulletproof_plus ? 4 : 3
   };
 
-  const uint64_t base_fee  = get_base_fee();
-  const uint64_t fee_multiplier = get_fee_multiplier(priority, get_fee_algorithm());
+  const uint64_t base_fee  = get_base_fee(priority);
   const uint64_t fee_quantization_mask = get_fee_quantization_mask();
 
   // throw if attempting a transaction with no destinations
@@ -9698,7 +9730,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
   // early out if we know we can't make it anyway
   // we could also check for being within FEE_PER_KB, but if the fee calculation
   // ever changes, this might be missed, so let this go through
-  const uint64_t min_fee = (fee_multiplier * base_fee * estimate_tx_size(use_rct, 1, fake_outs_count, 2, extra.size(), bulletproof, clsag, bulletproof_plus));
+  const uint64_t min_fee = (base_fee * estimate_tx_size(use_rct, 1, fake_outs_count, 2, extra.size(), bulletproof, clsag, bulletproof_plus));
   uint64_t balance_subtotal = 0;
   uint64_t unlocked_balance_subtotal = 0;
   for (uint32_t index_minor : subaddr_indices)
@@ -9720,7 +9752,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
   const size_t tx_weight_two_rings = estimate_tx_weight(use_rct, 2, fake_outs_count, 2, 0, bulletproof, clsag, bulletproof_plus);
   THROW_WALLET_EXCEPTION_IF(tx_weight_one_ring > tx_weight_two_rings, error::wallet_internal_error, "Estimated tx weight with 1 input is larger than with 2 inputs!");
   const size_t tx_weight_per_ring = tx_weight_two_rings - tx_weight_one_ring;
-  const uint64_t fractional_threshold = (fee_multiplier * base_fee * tx_weight_per_ring) / (use_per_byte_fee ? 1 : 1024);
+  const uint64_t fractional_threshold = (base_fee * tx_weight_per_ring) / (use_per_byte_fee ? 1 : 1024);
 
   // gather all dust and non-dust outputs belonging to specified subaddresses
   size_t num_nondust_outputs = 0;
@@ -9814,7 +9846,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
   {
     // this is used to build a tx that's 1 or 2 inputs, and 2 outputs, which
     // will get us a known fee.
-    uint64_t estimated_fee = estimate_fee(use_per_byte_fee, use_rct, 2, fake_outs_count, 2, extra.size(), bulletproof, clsag, bulletproof_plus, base_fee, fee_multiplier, fee_quantization_mask);
+    uint64_t estimated_fee = estimate_fee(use_per_byte_fee, use_rct, 2, fake_outs_count, 2, extra.size(), bulletproof, clsag, bulletproof_plus, base_fee, fee_quantization_mask);
     preferred_inputs = pick_preferred_rct_inputs(needed_money + estimated_fee, subaddr_account, subaddr_indices);
     if (!preferred_inputs.empty())
     {
@@ -9994,7 +10026,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
       pending_tx test_ptx;
 
       const size_t num_outputs = get_num_outputs(tx.dsts, m_transfers, tx.selected_transfers);
-      needed_fee = estimate_fee(use_per_byte_fee, use_rct ,tx.selected_transfers.size(), fake_outs_count, num_outputs, extra.size(), bulletproof, clsag, bulletproof_plus, base_fee, fee_multiplier, fee_quantization_mask);
+      needed_fee = estimate_fee(use_per_byte_fee, use_rct ,tx.selected_transfers.size(), fake_outs_count, num_outputs, extra.size(), bulletproof, clsag, bulletproof_plus, base_fee, fee_quantization_mask);
 
       auto try_carving_from_partial_payment = [&](uint64_t needed_fee, uint64_t available_for_fee)
       {
@@ -10048,7 +10080,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
         transfer_selected(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
           detail::digit_split_strategy, tx_dust_policy(::config::DEFAULT_DUST_THRESHOLD), test_tx, test_ptx);
       auto txBlob = t_serializable_object_to_blob(test_ptx.tx);
-      needed_fee = calculate_fee(use_per_byte_fee, test_ptx.tx, txBlob.size(), base_fee, fee_multiplier, fee_quantization_mask);
+      needed_fee = calculate_fee(use_per_byte_fee, test_ptx.tx, txBlob.size(), base_fee, fee_quantization_mask);
       available_for_fee = test_ptx.fee + test_ptx.change_dts.amount + (!test_ptx.dust_added_to_fee ? test_ptx.dust : 0);
       LOG_PRINT_L2("Made a " << get_weight_string(test_ptx.tx, txBlob.size()) << " tx, with " << print_money(available_for_fee) << " available for fee (" <<
         print_money(needed_fee) << " needed)");
@@ -10073,7 +10105,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
             transfer_selected(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
               detail::digit_split_strategy, tx_dust_policy(::config::DEFAULT_DUST_THRESHOLD), test_tx, test_ptx);
           txBlob = t_serializable_object_to_blob(test_ptx.tx);
-          needed_fee = calculate_fee(use_per_byte_fee, test_ptx.tx, txBlob.size(), base_fee, fee_multiplier, fee_quantization_mask);
+          needed_fee = calculate_fee(use_per_byte_fee, test_ptx.tx, txBlob.size(), base_fee, fee_quantization_mask);
           LOG_PRINT_L2("Made an attempt at a  final " << get_weight_string(test_ptx.tx, txBlob.size()) << " tx, with " << print_money(test_ptx.fee) <<
             " fee  and " << print_money(test_ptx.change_dts.amount) << " change");
         }
@@ -10256,13 +10288,12 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_all(uint64_t below
   const bool bulletproof = use_fork_rules(get_bulletproof_fork(), 0);
   const bool bulletproof_plus = use_fork_rules(get_bulletproof_plus_fork(), 0);
   const bool clsag = use_fork_rules(get_clsag_fork(), 0);
-  const uint64_t base_fee  = get_base_fee();
-  const uint64_t fee_multiplier = get_fee_multiplier(priority, get_fee_algorithm());
+  const uint64_t base_fee  = get_base_fee(priority);
   const size_t tx_weight_one_ring = estimate_tx_weight(use_rct, 1, fake_outs_count, 2, 0, bulletproof, clsag, bulletproof_plus);
   const size_t tx_weight_two_rings = estimate_tx_weight(use_rct, 2, fake_outs_count, 2, 0, bulletproof, clsag, bulletproof_plus);
   THROW_WALLET_EXCEPTION_IF(tx_weight_one_ring > tx_weight_two_rings, error::wallet_internal_error, "Estimated tx weight with 1 input is larger than with 2 inputs!");
   const size_t tx_weight_per_ring = tx_weight_two_rings - tx_weight_one_ring;
-  const uint64_t fractional_threshold = (fee_multiplier * base_fee * tx_weight_per_ring) / (use_per_byte_fee ? 1 : 1024);
+  const uint64_t fractional_threshold = (base_fee * tx_weight_per_ring) / (use_per_byte_fee ? 1 : 1024);
 
   THROW_WALLET_EXCEPTION_IF(unlocked_balance(subaddr_account, false) == 0, error::wallet_internal_error, "No unlocked balance in the specified account");
 
@@ -10371,8 +10402,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_from(const crypton
     rct::RangeProofPaddedBulletproof,
     bulletproof_plus ? 4 : 3
   };
-  const uint64_t base_fee  = get_base_fee();
-  const uint64_t fee_multiplier = get_fee_multiplier(priority, get_fee_algorithm());
+  const uint64_t base_fee  = get_base_fee(priority);
   const uint64_t fee_quantization_mask = get_fee_quantization_mask();
 
   LOG_PRINT_L2("Starting with " << unused_transfers_indices.size() << " non-dust outputs and " << unused_dust_indices.size() << " dust outputs");
@@ -10399,11 +10429,11 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_from(const crypton
     if (use_fork_rules(HF_VERSION_PER_BYTE_FEE))
     {
       const uint64_t estimated_tx_weight_with_one_extra_output = estimate_tx_weight(use_rct, tx.selected_transfers.size() + 1, fake_outs_count, tx.dsts.size()+1, extra.size(), bulletproof, clsag, bulletproof_plus);
-      fee_dust_threshold = calculate_fee_from_weight(base_fee, estimated_tx_weight_with_one_extra_output, fee_multiplier, fee_quantization_mask);
+      fee_dust_threshold = calculate_fee_from_weight(base_fee, estimated_tx_weight_with_one_extra_output, fee_quantization_mask);
     }
     else
     {
-      fee_dust_threshold = base_fee * fee_multiplier * (upper_transaction_weight_limit + 1023) / 1024;
+      fee_dust_threshold = base_fee * (upper_transaction_weight_limit + 1023) / 1024;
     }
 
     size_t idx =
@@ -10437,7 +10467,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_from(const crypton
       pending_tx test_ptx;
 
       const size_t num_outputs = get_num_outputs(tx.dsts, m_transfers, tx.selected_transfers);
-      needed_fee = estimate_fee(use_per_byte_fee, use_rct, tx.selected_transfers.size(), fake_outs_count, num_outputs, extra.size(), bulletproof, clsag, bulletproof_plus, base_fee, fee_multiplier, fee_quantization_mask);
+      needed_fee = estimate_fee(use_per_byte_fee, use_rct, tx.selected_transfers.size(), fake_outs_count, num_outputs, extra.size(), bulletproof, clsag, bulletproof_plus, base_fee, fee_quantization_mask);
 
       // add N - 1 outputs for correct initial fee estimation
       for (size_t i = 0; i < ((outputs > 1) ? outputs - 1 : outputs); ++i)
@@ -10452,7 +10482,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_from(const crypton
         transfer_selected(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
           detail::digit_split_strategy, tx_dust_policy(::config::DEFAULT_DUST_THRESHOLD), test_tx, test_ptx);
       auto txBlob = t_serializable_object_to_blob(test_ptx.tx);
-      needed_fee = calculate_fee(use_per_byte_fee, test_ptx.tx, txBlob.size(), base_fee, fee_multiplier, fee_quantization_mask);
+      needed_fee = calculate_fee(use_per_byte_fee, test_ptx.tx, txBlob.size(), base_fee, fee_quantization_mask);
       available_for_fee = test_ptx.fee + test_ptx.change_dts.amount;
       for (auto &dt: test_ptx.dests)
         available_for_fee += dt.amount;
@@ -10489,7 +10519,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_from(const crypton
           transfer_selected(tx.dsts, tx.selected_transfers, fake_outs_count, outs, unlock_time, needed_fee, extra,
             detail::digit_split_strategy, tx_dust_policy(::config::DEFAULT_DUST_THRESHOLD), test_tx, test_ptx);
         txBlob = t_serializable_object_to_blob(test_ptx.tx);
-        needed_fee = calculate_fee(use_per_byte_fee, test_ptx.tx, txBlob.size(), base_fee, fee_multiplier, fee_quantization_mask);
+        needed_fee = calculate_fee(use_per_byte_fee, test_ptx.tx, txBlob.size(), base_fee, fee_quantization_mask);
         LOG_PRINT_L2("Made an attempt at a final " << get_weight_string(test_ptx.tx, txBlob.size()) << " tx, with " << print_money(test_ptx.fee) <<
           " fee  and " << print_money(test_ptx.change_dts.amount) << " change");
       } while (needed_fee > test_ptx.fee);
@@ -10816,7 +10846,7 @@ std::vector<wallet2::pending_tx> wallet2::create_unmixable_sweep_transactions()
   const bool hf1_rules = use_fork_rules(2, 10); // first hard fork has version 2
   tx_dust_policy dust_policy(hf1_rules ? 0 : ::config::DEFAULT_DUST_THRESHOLD);
 
-  const uint64_t base_fee  = get_base_fee();
+  const uint64_t base_fee  = get_base_fee(1);
 
   // may throw
   std::vector<size_t> unmixable_outputs = select_available_unmixable_outputs();
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index f5da348a9..59f1ca94a 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -1427,8 +1427,9 @@ private:
     std::vector<std::pair<uint64_t, uint64_t>> estimate_backlog(const std::vector<std::pair<double, double>> &fee_levels);
     std::vector<std::pair<uint64_t, uint64_t>> estimate_backlog(uint64_t min_tx_weight, uint64_t max_tx_weight, const std::vector<uint64_t> &fees);
 
-    uint64_t estimate_fee(bool use_per_byte_fee, bool use_rct, int n_inputs, int mixin, int n_outputs, size_t extra_size, bool bulletproof, bool clsag, bool bulletproof_plus, uint64_t base_fee, uint64_t fee_multiplier, uint64_t fee_quantization_mask) const;
+    uint64_t estimate_fee(bool use_per_byte_fee, bool use_rct, int n_inputs, int mixin, int n_outputs, size_t extra_size, bool bulletproof, bool clsag, bool bulletproof_plus, uint64_t base_fee, uint64_t fee_quantization_mask) const;
     uint64_t get_fee_multiplier(uint32_t priority, int fee_algorithm = -1);
+    uint64_t get_base_fee(uint32_t priority);
     uint64_t get_base_fee();
     uint64_t get_fee_quantization_mask();
     uint64_t get_min_ring_size();