From 3e0ce348b721501c391acfc92f281e2bb8fb10a8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=BCrgen=20Nicklisch-Franken?= <jnf@arcor.de>
Date: Wed, 18 Sep 2024 15:44:44 +0200
Subject: [PATCH] cardano-node: added metric served.block.latest

---
 .../src/Cardano/Node/Tracing/Tracers.hs       |  4 +-
 .../Cardano/Node/Tracing/Tracers/Consensus.hs | 59 +++++++++++++++++++
 .../Cardano/Node/Tracing/Tracers/Startup.hs   |  4 +-
 3 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/cardano-node/src/Cardano/Node/Tracing/Tracers.hs b/cardano-node/src/Cardano/Node/Tracing/Tracers.hs
index dc12e1b5947..5ca7aa97042 100644
--- a/cardano-node/src/Cardano/Node/Tracing/Tracers.hs
+++ b/cardano-node/src/Cardano/Node/Tracing/Tracers.hs
@@ -34,7 +34,6 @@ import           Cardano.Node.Tracing.Tracers.KESInfo
 import           Cardano.Node.Tracing.Tracers.NodeToClient ()
 import           Cardano.Node.Tracing.Tracers.NodeToNode ()
 import           Cardano.Node.Tracing.Tracers.NodeVersion (getNodeVersion)
-
 import           Cardano.Node.Tracing.Tracers.NonP2P ()
 import           Cardano.Node.Tracing.Tracers.P2P ()
 import           Cardano.Node.Tracing.Tracers.Peer ()
@@ -267,6 +266,8 @@ mkConsensusTracers configReflection trBase trForward mbTrEKG _trDataPoint trConf
                 ["BlockFetch", "Server"]
     configureTracers configReflection trConfig [blockFetchServerTr]
 
+    !servedBlockLatestTr <- servedBlockLatest mbTrEKG
+
     !forgeKESInfoTr  <- mkCardanoTracer
                 trBase trForward mbTrEKG
                 ["Forge", "StateInfo"]
@@ -339,6 +340,7 @@ mkConsensusTracers configReflection trBase trForward mbTrEKG _trDataPoint trConf
            <> traceWith blockFetchClientMetricsTr
       , Consensus.blockFetchServerTracer = Tracer $
           traceWith blockFetchServerTr
+          <> traceWith servedBlockLatestTr
       , Consensus.forgeStateInfoTracer = Tracer $
           traceWith (traceAsKESInfo (Proxy @blk) forgeKESInfoTr)
       , Consensus.txInboundTracer = Tracer $
diff --git a/cardano-node/src/Cardano/Node/Tracing/Tracers/Consensus.hs b/cardano-node/src/Cardano/Node/Tracing/Tracers/Consensus.hs
index 27ca806f916..537a9d1dcd0 100644
--- a/cardano-node/src/Cardano/Node/Tracing/Tracers/Consensus.hs
+++ b/cardano-node/src/Cardano/Node/Tracing/Tracers/Consensus.hs
@@ -18,6 +18,7 @@ module Cardano.Node.Tracing.Tracers.Consensus
   , forgeTracerTransform
   , initialClientMetrics
   , calculateBlockFetchClientMetrics
+  , servedBlockLatest
   , ClientMetrics
   ) where
 
@@ -869,6 +870,64 @@ instance MetaTrace (TraceBlockFetchServerEvent blk) where
 
     allNamespaces = [Namespace [] ["SendBlock"]]
 
+--------------------------------------------------------------------------------
+-- Metric for server block latest
+--------------------------------------------------------------------------------
+
+data ServedBlock = ServedBlock {
+    maxSlotNo :: SlotNo
+  , localUp :: Word64
+  , servedBlocksLatest :: Word64
+}
+
+instance MetaTrace ServedBlock where
+    namespaceFor ServedBlock {} =
+      Namespace [] ["ServedBlockLatest"]
+
+    severityFor (Namespace [] ["ServedBlockLatest"]) _ = Just
+      Debug
+    severityFor _ _ = Nothing
+
+    documentFor _ = Nothing
+
+    metricsDocFor (Namespace [] ["ServedBlockLatest"]) =
+      [("served.block.latest", "")]
+    metricsDocFor _ = []
+
+    allNamespaces = [Namespace [] ["ServedBlockLatest"]]
+
+
+instance LogFormatting ServedBlock where
+  forMachine _mDtal ServedBlock {} = mempty
+
+  asMetrics ServedBlock {..} =
+    [IntM "served.block.latest" (fromIntegral servedBlocksLatest)]
+
+
+emptyServedBlocks :: ServedBlock
+emptyServedBlocks = ServedBlock 0 0 0
+
+servedBlockLatest ::
+     Maybe (Trace IO FormattedMessage)
+  -> IO (Trace IO  (TraceLabelPeer peer (TraceBlockFetchServerEvent blk)))
+servedBlockLatest mbTrEKG =
+      foldTraceM calculateServedBlockLatest emptyServedBlocks
+                  (metricsFormatter
+                    (mkMetricsTracer mbTrEKG))
+
+calculateServedBlockLatest :: ServedBlock
+                          -> LoggingContext
+                          -> TraceLabelPeer peer (TraceBlockFetchServerEvent blk)
+                          -> IO ServedBlock
+calculateServedBlockLatest ServedBlock{..} _lc (TraceLabelPeer _ (TraceBlockFetchServerSendBlock p)) =
+    case pointSlot p of
+      Origin    -> return $ ServedBlock maxSlotNo localUp servedBlocksLatest
+      At slotNo ->
+          case compare maxSlotNo slotNo of
+              LT -> return $ ServedBlock slotNo (localUp + 1) (localUp + 1)
+              GT -> return $ ServedBlock maxSlotNo localUp servedBlocksLatest
+              EQ -> return $ ServedBlock maxSlotNo (localUp + 1) (localUp + 1)
+
 --------------------------------------------------------------------------------
 -- TxInbound Tracer
 --------------------------------------------------------------------------------
diff --git a/cardano-node/src/Cardano/Node/Tracing/Tracers/Startup.hs b/cardano-node/src/Cardano/Node/Tracing/Tracers/Startup.hs
index d1c7854b508..28450f9142d 100644
--- a/cardano-node/src/Cardano/Node/Tracing/Tracers/Startup.hs
+++ b/cardano-node/src/Cardano/Node/Tracing/Tracers/Startup.hs
@@ -283,7 +283,9 @@ instance ( Show (BlockNodeToNodeVersion blk)
         NotEffective -> 0
       )]
   asMetrics (BICommon BasicInfoCommon {..}) =
-    [ PrometheusM "basicInfo" [("nodeStartTime", (pack . show) biNodeStartTime)]]
+    [ PrometheusM "basicInfo" [("nodeStartTime", (pack . show) biNodeStartTime)]
+    , IntM "node.start.time" ((ceiling . utcTimeToPOSIXSeconds) biNodeStartTime)
+    ]
   asMetrics _ = []
 
 instance MetaTrace  (StartupTrace blk) where