Expose LeiosDb volatile/immutable partition sizes as node metrics

cardano-node/src/Cardano/Node/Tracing/Tracers/Consensus.hs

@@ -85,6 +85,7 @@ import           Data.Time (NominalDiffTime)
 import           Data.Word (Word32, Word64)
 import           Network.TypedProtocol.Core
 
+import           LeiosDemoDb.Trace (TraceLeiosDb (..))
 import           LeiosDemoTypes (TraceLeiosKernel (..), TraceLeiosPeer (..),
                    traceLeiosKernelToObject, traceLeiosPeerToObject)
 import           LeiosUtils.CallTrace (SomeJsonCallTrace (..), callTraceToObject)
@@ -2361,7 +2362,43 @@ instance LogFormatting TraceLeiosKernel where
     TraceLeiosAnnouncementAccepted src equiv fields mbAge ->
       "EB announcement accepted from " <> Text.pack (show src)
         <> " (" <> Text.pack (show equiv) <> "): " <> Text.pack (show fields) <> " age=" <> showT mbAge
-  asMetrics _ = []
+
+  -- The LeiosDb size gauges and activity counters, which together make the
+  -- volatile/immutable partitioning of the Leios DB observable: the immutable
+  -- gauges climb with what the immutable chain references, while GC keeps the
+  -- volatile ones bounded by evicting un-certified leftovers. Both size events
+  -- ride the same stats-sampler timer.
+  --
+  -- NOTE: metric names live in a single flat global namespace (the 'Namespace'
+  -- above names the log message, not the metric), so they are prefixed to stay
+  -- unique. 'IntM' gets an "_int" suffix and 'CounterM' a "_counter" one, on top
+  -- of 'TraceOptionMetricsPrefix'.
+  asMetrics = \case
+    -- Sampled on a timer, so these exist from node start.
+    TraceLeiosDb TraceLeiosDbVolatileStats { volatileEbs, volatileEbTxs, volatileTxs
+                                      , dbFileBytes, walBytes } ->
+      [ IntM "leiosDbVolatileEbs"    (fromIntegral volatileEbs)
+      , IntM "leiosDbVolatileEbTxs"  (fromIntegral volatileEbTxs)
+      , IntM "leiosDbVolatileTxs"    (fromIntegral volatileTxs)
+      , IntM "leiosDbFileBytes" dbFileBytes
+      , IntM "leiosDbWalBytes"  walBytes
+      ]
+    TraceLeiosDb TraceLeiosDbImmutableStats { immutableEbs, immutableEbTxs, immutableTxs } ->
+      [ IntM "leiosDbImmutableEbs"   (fromIntegral immutableEbs)
+      , IntM "leiosDbImmutableEbTxs" (fromIntegral immutableEbTxs)
+      , IntM "leiosDbImmutableTxs"   (fromIntegral immutableTxs)
+      ]
+    TraceLeiosDb TraceLeiosDbCopiedToImmutable { copiedEbs, copiedEbTxs, copiedTxs } ->
+      [ CounterM "leiosDbCopiedEbs"   (Just copiedEbs)
+      , CounterM "leiosDbCopiedEbTxs" (Just copiedEbTxs)
+      , CounterM "leiosDbCopiedTxs"   (Just copiedTxs)
+      ]
+    TraceLeiosDb TraceLeiosDbEvicted { evictedEbs, evictedEbTxs, evictedTxs } ->
+      [ CounterM "leiosDbEvictedEbs"   (Just evictedEbs)
+      , CounterM "leiosDbEvictedEbTxs" (Just evictedEbTxs)
+      , CounterM "leiosDbEvictedTxs"   (Just evictedTxs)
+      ]
+    _ -> []
 
 instance MetaTrace TraceLeiosKernel where
   namespaceFor MkTraceLeiosKernel{}          = Namespace [] ["Msg"]
@@ -2377,16 +2414,44 @@ instance MetaTrace TraceLeiosKernel where
   namespaceFor TraceLeiosCertified{}         = Namespace [] ["Certified"]
   namespaceFor TraceLeiosNotVoted{}          = Namespace [] ["NotVoted"]
   namespaceFor TraceLeiosDbException{}       = Namespace [] ["DbException"]
+  -- Call spans get their own namespace under Db so their severity and
+  -- frequency can be configured apart from the stats gauges (a dozen span
+  -- events per GC vs one stats event).
+  namespaceFor (TraceLeiosDb TraceLeiosDbCall{}) = Namespace [] ["Db", "Call"]
   namespaceFor TraceLeiosDb{}                = Namespace [] ["Db"]
   namespaceFor TraceLeiosCertifiedAndAnnounced{} = Namespace [] ["CertifiedAndAnnounced"]
   namespaceFor TraceLeiosAnnouncementAccepted{}  = Namespace [] ["AnnouncementAccepted"]
 
   severityFor (Namespace _ ["DbException"])        _ = Just Error
   severityFor (Namespace _ ["BlockPointMissing"])  _ = Just Warning
+  severityFor (Namespace _ ["Db", "Call"])         _ = Just Debug
   severityFor _                                    _ = Just Info
 
   documentFor _ = Nothing
 
+  -- REQUIRED for the metrics in 'asMetrics' to be emitted at all, despite the
+  -- name: 'hasNoMetrics' is @all (null . metricsDocFor) allNamespaces@, and
+  -- 'mkCardanoTracer' uses it to silence a tracer's entire metrics branch at
+  -- configuration time. Leaving this at its @[]@ default drops every metric
+  -- above, with no error.
+  metricsDocFor (Namespace _ ["Db"]) =
+    [ ("leiosDbVolatileEbs",    "LeiosDb: announced EB rows in the volatile partition")
+    , ("leiosDbVolatileEbTxs",  "LeiosDb: EB body rows in the volatile partition")
+    , ("leiosDbVolatileTxs",    "LeiosDb: transactions in the volatile partition")
+    , ("leiosDbImmutableEbs",   "LeiosDb: announced EB rows in the immutable partition")
+    , ("leiosDbImmutableEbTxs", "LeiosDb: EB body rows in the immutable partition")
+    , ("leiosDbImmutableTxs",   "LeiosDb: transactions in the immutable partition")
+    , ("leiosDbFileBytes", "LeiosDb: size of the main database file in bytes")
+    , ("leiosDbWalBytes",  "LeiosDb: current size of the write-ahead log in bytes")
+    , ("leiosDbCopiedEbs",   "LeiosDb: announcement rows copied into the immutable partition")
+    , ("leiosDbCopiedEbTxs", "LeiosDb: EB body rows copied into the immutable partition")
+    , ("leiosDbCopiedTxs",   "LeiosDb: transactions copied into the immutable partition")
+    , ("leiosDbEvictedEbs",   "LeiosDb: announcement rows garbage collected from the volatile partition")
+    , ("leiosDbEvictedEbTxs", "LeiosDb: EB body rows garbage collected from the volatile partition")
+    , ("leiosDbEvictedTxs",   "LeiosDb: transactions garbage collected from the volatile partition")
+    ]
+  metricsDocFor _ = []
+
   allNamespaces =
     [ Namespace [] ["Msg"]
     , Namespace [] ["BlockAcquired"]
@@ -2402,6 +2467,7 @@ instance MetaTrace TraceLeiosKernel where
     , Namespace [] ["NotVoted"]
     , Namespace [] ["DbException"]
     , Namespace [] ["Db"]
+    , Namespace [] ["Db", "Call"]
     , Namespace [] ["CertifiedAndAnnounced"]
     , Namespace [] ["AnnouncementAccepted"]
     ]