[move] performance metrics (#132)

Co-authored-by: 0o-de-lally <[email protected]>

Author: sirouk

framework/libra-framework/sources/modified_source/stake.move

@@ -188,6 +188,31 @@ module diem_framework::stake {
         fees_table: Table<address, Coin<LibraCoin>>,
     }
 
+    #[view]
+    /// @return: tuple
+    /// - u64: number of proposals
+    /// - address: the validator
+    public fun get_highest_net_proposer(): (u64, address) acquires ValidatorSet,
+    ValidatorPerformance, ValidatorConfig
+    {
+      let vals = get_current_validators();
+      let highest_net_proposals = 0;
+      let highest_addr = @0x0;
+      vector::for_each(vals, |v| {
+        let idx = get_validator_index(v);
+        let (success, fail) = get_current_epoch_proposal_counts(idx);
+        if (success > fail) {
+          let net = success - fail;
+
+          if (net > highest_net_proposals) {
+            highest_net_proposals = net;
+            highest_addr = v;
+          }
+        }
+      });
+      (highest_net_proposals, highest_addr)
+    }
+
 
     #[view]
     /// Returns the list of active validators
@@ -250,13 +275,29 @@ module diem_framework::stake {
     }
 
     #[view]
-    /// Return the number of successful and failed proposals for the proposal at the given validator index.
+    /// @return: tuple
+    /// - u64:  the number of successful
+    /// - u64: and failed proposals for the proposal at the given validator index.
     public fun get_current_epoch_proposal_counts(validator_index: u64): (u64, u64) acquires ValidatorPerformance {
         let validator_performances = &borrow_global<ValidatorPerformance>(@diem_framework).validators;
         let validator_performance = vector::borrow(validator_performances, validator_index);
         (validator_performance.successful_proposals, validator_performance.failed_proposals)
     }
 
+    #[view]
+    /// Get net proposals from address
+    /// @return:  u64:  the number of net proposals (success - fail)
+    public fun get_val_net_proposals(val: address): u64 acquires
+    ValidatorPerformance, ValidatorConfig {
+        let idx = get_validator_index(val);
+        let (proposed, failed) = get_current_epoch_proposal_counts(idx);
+        if (proposed > failed) {
+          proposed - failed
+        } else {
+          0
+        }
+    }
+
     #[view]
     /// Return the validator's config.
     public fun get_validator_config(validator_address: address): (vector<u8>, vector<u8>, vector<u8>) acquires ValidatorConfig {
@@ -314,9 +355,6 @@ module diem_framework::stake {
         if (account_address != operator) {
             set_operator(owner, operator)
         };
-        // if (account_address != voter) {
-        //     set_delegated_voter(owner, voter)
-        // };
     }
 
     /// Initialize the validator account and give ownership to the signing account.
@@ -541,29 +579,18 @@ module diem_framework::stake {
     }
 
     /// Triggers at epoch boundary. This function shouldn't abort.
-    ///
-    /// 1. Distribute transaction fees and rewards to stake pools of active and pending inactive validators (requested
-    /// to leave but not yet removed).
-    /// 2. Officially move pending active stake to active and move pending inactive stake to inactive.
-    /// The staking pool's voting power in this new epoch will be updated to the total active stake.
-    /// 3. Add pending active validators to the active set if they satisfy requirements so they can vote and remove
-    /// pending inactive validators so they no longer can vote.
-    /// 4. The validator's voting power in the validator set is updated to be the corresponding staking pool's voting
-    // / power.
+    /// NOTE: THIS ONLY EXISTS FOR VENDOR TESTS
     public(friend) fun on_new_epoch() acquires ValidatorConfig, ValidatorPerformance, ValidatorSet {
         let validator_set = borrow_global_mut<ValidatorSet>(@diem_framework);
-        // let config = staking_config::get();
         let validator_perf = borrow_global_mut<ValidatorPerformance>(@diem_framework);
 
 
         // Update active validator set so that network address/public key change takes effect.
         // Moreover, recalculate the total voting power, and deactivate the validator whose
         // voting power is less than the minimum required stake.
         let next_epoch_validators = vector::empty();
-        // let (minimum_stake, _) = staking_config::get_required_stake(&config);
         let minimum_stake = 0;
 
-
         let vlen = vector::length(&validator_set.active_validators);
         let total_voting_power = 0;
         let i = 0;
@@ -595,13 +622,8 @@ module diem_framework::stake {
         validator_set.total_voting_power = total_voting_power;
 
 
-        // validator_set.total_joining_power = 0;
-
         // Update validator indices, reset performance scores, and renew lockups.
         validator_perf.validators = vector::empty();
-        // let recurring_lockup_duration_secs = 0;
-        //staking_config::get_recurring_lockup_duration(&config);
-
 
         let vlen = vector::length(&validator_set.active_validators);
         let validator_index = 0;

framework/libra-framework/sources/ol_sources/grade.move

@@ -11,19 +11,86 @@ module ol_framework::grade {
     use diem_framework::stake;
     use std::fixed_point32::{Self, FixedPoint32};
 
+    // use diem_std::debug::print;
+
+    /// what threshold of failed props should the network allow
+    /// one validator before jailing?
+    const FAILED_PROPS_THRESHOLD_PCT: u64 =20;
+
+    /// how far behind the leading validator by net proposals
+    /// should the trailing validator be allowed
+    const TRAILING_VALIDATOR_THRESHOLD: u64 = 5;
+
 
     #[view]
     /// returns if the validator passed or failed, and the number of proposals
     /// and failures, and the ratio.
-    /// returns: is the validator compliant, proposed blocks, failed blocks, and the ratio of proposed to failed.
+    /// @return: tuple
+    /// bool: is the validator compliant,
+    /// u64: proposed blocks,
+    /// u64: failed blocks, and
+    /// FixedPoint32: the ratio of proposed to failed.
 
-    public fun get_validator_grade(node_addr: address): (bool, u64, u64, FixedPoint32) {
+    public fun get_validator_grade(node_addr: address, highest_net_props: u64): (bool, u64, u64, FixedPoint32) {
       let idx = stake::get_validator_index(node_addr);
       let (proposed, failed) = stake::get_current_epoch_proposal_counts(idx);
 
-      let compliant = proposed > failed;
+      // first pass: should have accepted proposals
+      if (proposed < failed) {
+        return (false, proposed, failed, fixed_point32::create_from_raw_value(0))
+      };
+
+      let compliant = has_good_success_ratio(proposed, failed) &&
+      does_not_trail(proposed, failed, highest_net_props);
+
       // make failed at leat 1 to avoid division by zero
       (compliant, proposed, failed, fixed_point32::create_from_rational(proposed, (failed + 1)))
     }
 
+    /// Does the validator produce far more valid proposals than failed ones.
+    /// suggesting here an initial 80% threshold. (i.e. only allow 20% failed
+    /// proposals)
+    /// It's unclear what the right ratio should be. On problematic epochs
+    /// (i.e. low consensus) we may want to have some allowance for errors.
+    fun has_good_success_ratio(proposed: u64, failed: u64): bool {
+
+      let fail_ratio = if (proposed >= failed) {
+        // +1 to prevent denomiator zero error
+        fixed_point32::create_from_rational(failed, (proposed + 1))
+      } else { return false };
+
+      // failure ratio shoul dbe BELOW FAILED_PROPS_THRESHOLD_PCT
+      let is_above = fixed_point32::multiply_u64(100, fail_ratio) < FAILED_PROPS_THRESHOLD_PCT;
+
+      is_above
+
+    }
+
+    /// is this user very far behind the leading proposer.
+    /// in 0L we give all validator seats equal chances of proposing (leader).
+    /// However, the "leader reputation" algorithm in LibraBFT, will score
+    /// validators. The score is based on successful signing and propagation of
+    /// blocks. So people with lower scores might a) not be very competent or,
+    /// b) are in networks that are further removed from the majority (remote
+    /// data centers, home labs, etc). So we shouldn't bias too heavily on this
+    // performance metric, because it will reduce heterogeneity (the big D).
+    /// Unfortunately the reputation heuristic score is not on-chain
+    /// (perhaps a future optimization).
+    /// A good solution would be to drop the lowest % of RMS (root mean
+    /// squared) of proposal. Perhaps the lowest 10% of the validator set RMS.
+    /// But that's harder to understand by the validators (comprehension is
+    // important when we are trying to shape behavior).
+    /// So a simpler and more actionable metric might be:
+    /// drop anyone who proposed less than X% of the LEADING proposal.
+    /// This has an additional quality, which allows for the highest performing
+    // validators to be a kind of "vanguard" rider ("forerider"?) which sets the
+    // pace for the lowest performer.
+    fun does_not_trail(proposed: u64, failed: u64, highest_net_props: u64): bool {
+      if ((proposed > failed) && (highest_net_props > 0)) {
+        let net = proposed - failed;
+        let net_props_vs_leader= fixed_point32::create_from_rational(net,
+        highest_net_props);
+        fixed_point32::multiply_u64(100, net_props_vs_leader) > FAILED_PROPS_THRESHOLD_PCT
+      } else { false }
+    }
 }

framework/libra-framework/sources/ol_sources/mock.move

@@ -52,9 +52,9 @@ module ol_framework::mock {
   #[test_only]
   public fun mock_case_1(vm: &signer, addr: address){
       assert!(stake::is_valid(addr), 01);
-      stake::mock_performance(vm, addr, 1, 0);
-      let (compliant, _, _, _) = grade::get_validator_grade(addr);
-      assert!(compliant, 777703);
+      stake::mock_performance(vm, addr, 100, 10);
+      let (compliant, _, _, _) = grade::get_validator_grade(addr, 100);
+      assert!(compliant, 01);
     }
 
 
@@ -63,8 +63,8 @@ module ol_framework::mock {
     public fun mock_case_4(vm: &signer, addr: address){
       assert!(stake::is_valid(addr), 01);
       stake::mock_performance(vm, addr, 0, 100); // 100 failing proposals
-      let (compliant, _, _, _) = grade::get_validator_grade(addr);
-      assert!(!compliant, 777703);
+      let (compliant, _, _, _) = grade::get_validator_grade(addr, 0);
+      assert!(!compliant, 02);
     }
 
     // Mock all nodes being compliant case 1
@@ -114,7 +114,7 @@ module ol_framework::mock {
       // make all validators pay auction fee
       // the clearing price in the fibonacci sequence is is 1
       let (alice_bid, _) = proof_of_fee::current_bid(*vector::borrow(&vals, 0));
-      assert!(alice_bid == 1, 777703);
+      assert!(alice_bid == 1, 03);
       (vals, bids, expiry)
     }
 
@@ -311,8 +311,6 @@ module ol_framework::mock {
 
   #[test(root = @ol_framework)]
   public entry fun meta_val_perf(root: signer) {
-    // genesis();
-
     let set = genesis_n_vals(&root, 4);
     assert!(vector::length(&set) == 4, 7357001);
 

framework/libra-framework/sources/ol_sources/musical_chairs.move

@@ -148,11 +148,11 @@ module ol_framework::musical_chairs {
         // TODO: use status.move is_operating
         if (epoch < 2) return (validators, non_compliant_nodes, fixed_point32::create_from_rational(1, 1));
 
-
+        let (highest_net_props, _val) = stake::get_highest_net_proposer();
         let i = 0;
         while (i < val_set_len) {
             let addr = *vector::borrow(&validators, i);
-            let (compliant, _, _, _) = grade::get_validator_grade(addr);
+            let (compliant, _, _, _) = grade::get_validator_grade(addr, highest_net_props);
             // let compliant = true;
             if (compliant) {
                 vector::push_back(&mut compliant_nodes, addr);

framework/libra-framework/sources/ol_sources/tests/stake.test.move

@@ -166,10 +166,98 @@ module ol_framework::test_stake {
     // now make Eve not compliant
     let eve = @0x1000e;
     mock::mock_case_4(&root, eve);
-    let (compliant, _, _, _) = grade::get_validator_grade(eve);
+    let (compliant, _, _, _) = grade::get_validator_grade(eve, 0);
     assert!(!compliant, 735701);
 
   }
 
+  // Scenario: There's one validator that is a straggler
+  // that validator should be dropped when we "grade"
+  // the validators.
+  // The validator has an acceptable success ratio
+  #[test(root = @ol_framework)]
+  fun drop_trailing(root: signer) {
+
+    let set = mock::genesis_n_vals(&root, 8);
+    testnet::unset(&root); // set to production mode
+
+    let default_valid_props = 500;
+    // populate some performance
+    let i = 0;
+    while (i < vector::length(&set)) {
+      let addr = vector::borrow(&set, i);
+
+      let valid_props =  default_valid_props; // make all validators have
+      let invalid_props = 1;
+
+      stake::mock_performance(&root, *addr, valid_props, invalid_props); //
+      // increasing performance for each
+      i = i + 1;
+    };
+
+    // set alice to be "trailing"
+    // this will be less than 5% of the leading validator
+    stake::mock_performance(&root, @0x1000a, 5, 1);
+    stake::mock_performance(&root, @0x10011, 1000, 1);
+
+    let (highest_score, _addr) = stake::get_highest_net_proposer();
+
+    // LOWEST TRAILING VALIDATOR WILL BE OUT
+    let lowest_score = stake::get_val_net_proposals(@0x1000a);
+
+    assert!(highest_score > (lowest_score*20), 7357001);
+    let (a, _, _, _) = grade::get_validator_grade(@0x1000a, highest_score);
+    assert!(a == false, 73570002);
+
+    // Second lowest is fine
+    let (b, _, _, _) = grade::get_validator_grade(@0x1000c, highest_score);
+    assert!(b == true, 73570003);
+
+    // and top is also fine
+    let (top, _, _, _) = grade::get_validator_grade(@0x10011, highest_score);
+    assert!(top == true, 73570004);
+
+  }
+
+  // Scenario: one validator has too many failing
+  // proposals as a ratio to successful ones.
+  #[test(root = @ol_framework)]
+  fun drop_low_performance_ratio(root: signer) {
+
+    let set = mock::genesis_n_vals(&root, 8);
+    testnet::unset(&root); // set to production mode
+
+    let default_valid_props = 500;
+    // populate some performance
+    let i = 0;
+    while (i < vector::length(&set)) {
+      let addr = vector::borrow(&set, i);
+
+      let valid_props =  default_valid_props; // make all validators have
+      let invalid_props = 1;
+
+      stake::mock_performance(&root, *addr, valid_props, invalid_props); //
+      // increasing performance for each
+      i = i + 1;
+    };
+
+    // alice is NOT trailing in proposals
+    // but the percent of failed proposals are too high
+    // above 10%
+    // in this example 40% failing proposals
+    stake::mock_performance(&root, @0x1000a, 500, 200);
+
+    let (highest_score, _addr) = stake::get_highest_net_proposer();
+
+    // Lots of failing proposals will make you drop out
+    let (a, _, _, _) = grade::get_validator_grade(@0x1000a, highest_score);
+    assert!(a == false, 73570002);
+
+    // Other accounts are ok
+    let (b, _, _, _) = grade::get_validator_grade(@0x1000c, highest_score);
+    assert!(b == true, 73570003);
+
+  }
+
 
 }

framework/libra-framework/sources/ol_sources/validator_universe.move

@@ -1,5 +1,3 @@
-///////////////////////////////////////////////////////////////////////////
-// 0L Module
 // ValidatorUniverse
 ///////////////////////////////////////////////////////////////////////////
 
@@ -11,7 +9,6 @@ module diem_framework::validator_universe {
   use ol_framework::vouch;
   use diem_framework::stake;
 
-
   #[test_only]
   use ol_framework::testnet;
   #[test_only]
@@ -27,8 +24,6 @@ module diem_framework::validator_universe {
       validators: vector<address>
   }
 
-  // * DEPRECATED JailBit struct, now in jail.move * //
-
   // Genesis function to initialize ValidatorUniverse struct in 0x0.
   // This is triggered in new epoch by Configuration in Genesis.move
   // Function code: 01 Prefix: 220101