feat: less agressive fast updates reporting

Author: miha-gyergyek-aflabs

observer/observer.py

@@ -151,6 +151,26 @@ def calculate_update_from_tx(config: Configuration, w: AsyncWeb3, tx: TxData):
     return signing_policy_address, address, signed_array
 
 
+async def get_block_production(w: AsyncWeb3) -> float:
+    latest_block = await w.eth.get_block("latest")
+    assert "timestamp" in latest_block
+    assert "number" in latest_block
+    to_compare = min(1_000_000, int(latest_block["number"]) - 1)
+    comparison_block = await w.eth.get_block(int(latest_block["number"]) - to_compare)
+    assert "timestamp" in comparison_block
+    time_delta = latest_block["timestamp"] - comparison_block["timestamp"]
+    block_production = time_delta / to_compare
+    return block_production
+
+
+def calculate_maximum_exponent(block_production: float, config: Configuration) -> int:
+    blocks_in_epoch = int(
+        config.epoch.reward_epoch_factory.duration() / block_production
+    )
+    max_exponent = blocks_in_epoch // 100
+    return max_exponent
+
+
 async def find_voter_registration_blocks(
     w: AsyncWeb3,
     current_block_id: int,
@@ -340,6 +360,9 @@ async def observer_loop(config: Configuration) -> None:
     )
     spb = SigningPolicy.builder().for_epoch(reward_epoch.next)
 
+    block_production = await get_block_production(w)
+    maximum_exponent = calculate_maximum_exponent(block_production, config)
+
     # print("Signing policy created for reward epoch", current_rid)
     # print("Reward Epoch object created", reward_epoch_info)
     # print("Current Reward Epoch status", reward_epoch_info.status(config))
@@ -666,13 +689,17 @@ async def observer_loop(config: Configuration) -> None:
             messages.extend(event_messages)
             entity = signing_policy.entity_mapper.by_identity_address[tia]
 
-            # perform all minimal condition checks here and reset node connections
+            # perform all minimal condition checks here
             if int(time.time() - last_minimal_conditions_check) > 60:
                 min_cond_messages: list[Message] = []
 
                 min_cond_messages.extend(
                     minimal_conditions.calculate_ftso_block_latency_feeds(
-                        entity, signing_policy, fum.last_update_block, block
+                        maximum_exponent,
+                        entity,
+                        signing_policy,
+                        fum.last_update_block,
+                        block,
                     )
                 )
                 min_cond_messages.extend(

observer/validation/minimal_conditions.py

@@ -92,6 +92,7 @@ def calculate_ftso_anchor_feeds(
 
     def calculate_ftso_block_latency_feeds(
         self,
+        max_exponent: int,
         entity: Entity,
         sp: SigningPolicy,
         last_update: int,
@@ -108,22 +109,31 @@ def calculate_ftso_block_latency_feeds(
 
         per_block = MinimalConditionsConfig.fast_updates_updates_per_block
         n_blocks = current_block - last_update
-        probability_bips = int(
-            10_000 * (1 - per_block * weight / total_weight) ** (n_blocks)
+        if n_blocks >= max_exponent:
+            n_blocks = max_exponent
+        probability_ppb = int(
+            1_000_000_000 * (1 - per_block * weight / total_weight) ** (n_blocks)
         )
-
-        if probability_bips > 100:
+        if n_blocks < max_exponent:
+            if probability_ppb <= 100:
+                level = MessageLevel.CRITICAL
+                messages.append(
+                    mb.build(
+                        level,
+                        f"didn't submit a fast update in {n_blocks} blocks",
+                    )
+                )
             return messages
 
         level = MessageLevel.WARNING
-        if probability_bips <= 10:
+        if probability_ppb <= 100:
             level = MessageLevel.CRITICAL
 
         messages.append(
             mb.build(
                 level,
-                f"didn't submit fast update in {n_blocks} "
-                f"(false positive probability: {probability_bips / 100:.2f})%",
+                f"didn't submit a fast update in {n_blocks} blocks "
+                f"(false positive probability: {probability_ppb / 10_000_000:.5f})%",
             )
         )