Merge #3500

3500: Use block download when ranking peers r=karknu a=karknu Use both who ever gave us a header first, and who ever provided us with the block first when ranking peers in deadline mode. For larger blocks forged far away it is likely that we learned of the header from a node on another continent, but the node from which we first downloaded the block is much closer. This change gives both nodes credit. Co-authored-by: Karl Knutsson <karl.knutsson@iohk.io>
IntersectMBO · Nov 23, 2021 · 273f006 · 273f006
2 parents 67a7c69 + 2d4be8c
commit 273f006
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Showing 3 changed files with 32 additions and 8 deletions.
diff --git a/ouroboros-network/src/Ouroboros/Network/Diffusion/Policies.hs b/ouroboros-network/src/Ouroboros/Network/Diffusion/Policies.hs
@@ -81,10 +81,13 @@ simplePeerSelectionPolicy rngVar getChurnMode metrics = PeerSelectionPolicy {
     hotDemotionPolicy _ _ _ available pickNum = do
         mode <- getChurnMode
         scores <- case mode of
-                       ChurnModeNormal ->
-                           upstreamyness <$> getHeaderMetrics metrics
+                       ChurnModeNormal -> do
+                           hup <- upstreamyness <$> getHeaderMetrics metrics
+                           bup <- fetchynessBlocks <$> getFetchedMetrics metrics
+                           return $ Map.unionWith (+) hup bup
+
                        ChurnModeBulkSync ->
-                           fetchyness <$> getFetchedMetrics metrics
+                           fetchynessBytes <$> getFetchedMetrics metrics
         available' <- addRand available (,)
         return $ Set.fromList
              . map fst

diff --git a/ouroboros-network/src/Ouroboros/Network/PeerSelection/PeerMetric.hs b/ouroboros-network/src/Ouroboros/Network/PeerSelection/PeerMetric.hs
@@ -145,11 +145,11 @@ upstreamyness = Pq.fold' count Map.empty
 
 -- Returns a Map which counts the number of bytes downloaded
 -- for a given peer.
-fetchyness
+fetchynessBytes
     :: forall p.  ( Ord p )
     => SlotMetric (p, SizeInBytes)
     -> Map p Int
-fetchyness = Pq.fold' count Map.empty
+fetchynessBytes = Pq.fold' count Map.empty
   where
     count :: Int
           -> SlotNo
@@ -163,5 +163,24 @@ fetchyness = Pq.fold' count Map.empty
         fn Nothing = Just $ fromIntegral bytes
         fn (Just oldBytes) = Just $! oldBytes + fromIntegral bytes
 
+-- Returns a Map which counts the number of times a given peer
+-- was the first we downloaded a block from.
+fetchynessBlocks
+    :: forall p.  ( Ord p )
+    => SlotMetric (p, SizeInBytes)
+    -> Map p Int
+fetchynessBlocks = Pq.fold' count Map.empty
+  where
+    count :: Int
+          -> SlotNo
+          -> ((p, SizeInBytes), Time)
+          -> Map p Int
+          -> Map p Int
+    count _ _ ((peer, _),_) m =
+        Map.alter fn peer m
+      where
+        fn :: Maybe Int -> Maybe Int
+        fn Nothing = Just 1
+        fn (Just c) = Just $! c + 1
 
 
diff --git a/ouroboros-network/test/Test/Ouroboros/Network/Diffusion/Policies.hs b/ouroboros-network/test/Test/Ouroboros/Network/Diffusion/Policies.hs
@@ -182,9 +182,11 @@ prop_hotToWarmM ArbitraryPolicyArguments{..} seed = do
               -> m Property
     noneWorse metrics pickedSet = do
         scores <- atomically $ case apaChurnMode of
-                      ChurnModeNormal -> upstreamyness <$>
-                          getHeaderMetrics metrics
-                      ChurnModeBulkSync -> fetchyness <$>
+                      ChurnModeNormal -> do
+                          hup <- upstreamyness <$> getHeaderMetrics metrics
+                          bup <- fetchynessBlocks <$> getFetchedMetrics metrics
+                          return $ Map.unionWith (+) hup bup
+                      ChurnModeBulkSync -> fetchynessBytes <$>
                           getFetchedMetrics metrics
         let (picked, notPicked) = Map.partitionWithKey fn scores
             maxPicked = maximum $ Map.elems picked