From d1cfe9d2a144ae0aec439b1809f03582c298fad8 Mon Sep 17 00:00:00 2001
From: Sadanand Shenoy <sadanand.shenoy@cloudera.com>
Date: Mon, 20 May 2024 17:34:51 +0530
Subject: [PATCH] HDDS-10883. Improve logging in Recon for finalising DN logic.

---
 .../hadoop/hdds/scm/node/SCMNodeManager.java  |  5 ++++
 .../ozone/recon/scm/ReconNodeManager.java     | 29 +++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/SCMNodeManager.java b/hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/SCMNodeManager.java
index d3559a7d9747..3790214f5268 100644
--- a/hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/SCMNodeManager.java
+++ b/hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/SCMNodeManager.java
@@ -691,6 +691,11 @@ public void processLayoutVersionReport(DatanodeDetails datanodeDetails,
       return;
     }
 
+    sendFinalizeToDatanodeIfNeeded(datanodeDetails, layoutVersionReport);
+  }
+
+  protected void sendFinalizeToDatanodeIfNeeded(DatanodeDetails datanodeDetails,
+      LayoutVersionProto layoutVersionReport) {
     // Software layout version is hardcoded to the SCM.
     int scmSlv = scmLayoutVersionManager.getSoftwareLayoutVersion();
     int dnSlv = layoutVersionReport.getSoftwareLayoutVersion();
diff --git a/hadoop-ozone/recon/src/main/java/org/apache/hadoop/ozone/recon/scm/ReconNodeManager.java b/hadoop-ozone/recon/src/main/java/org/apache/hadoop/ozone/recon/scm/ReconNodeManager.java
index 6232fb49070f..bd555422830f 100644
--- a/hadoop-ozone/recon/src/main/java/org/apache/hadoop/ozone/recon/scm/ReconNodeManager.java
+++ b/hadoop-ozone/recon/src/main/java/org/apache/hadoop/ozone/recon/scm/ReconNodeManager.java
@@ -344,4 +344,33 @@ public void removeNode(DatanodeDetails datanodeDetails) throws NodeNotFoundExcep
         datanodeDetails.getUuid());
   }
 
+  @Override
+  protected void sendFinalizeToDatanodeIfNeeded(DatanodeDetails datanodeDetails,
+      LayoutVersionProto layoutVersionReport) {
+    // Recon should do nothing here.
+    int scmSlv = getLayoutVersionManager().getSoftwareLayoutVersion();
+    int scmMlv = getLayoutVersionManager().getMetadataLayoutVersion();
+    int dnSlv = layoutVersionReport.getSoftwareLayoutVersion();
+    int dnMlv = layoutVersionReport.getMetadataLayoutVersion();
+
+    if (dnSlv > scmSlv) {
+      LOG.error("Invalid data node reporting to Recon : {}. " +
+              "DataNode SoftwareLayoutVersion = {}, Recon/SCM " +
+              "SoftwareLayoutVersion = {}",
+          datanodeDetails.getHostName(), dnSlv, scmSlv);
+    }
+
+    if (scmMlv == scmSlv) {
+      // Recon metadata is finalised.
+      if (dnMlv < scmMlv) {
+        if (LOG.isDebugEnabled()) {
+          LOG.debug("Data node {} reports a lower MLV than Recon "
+                  + "DataNode MetadataLayoutVersion = {}, Recon/SCM "
+                  + "MetadataLayoutVersion = {}. SCM needs to finalize this DN",
+              datanodeDetails.getHostName(), dnMlv, scmMlv);
+        }
+      }
+    }
+
+  }
 }