print connectivity matrix only if changed #11

Author: kelvich

contrib/mmts/multimaster.c

@@ -230,6 +230,7 @@ static ExecutorFinish_hook_type PreviousExecutorFinishHook;
 static ProcessUtility_hook_type PreviousProcessUtilityHook;
 static shmem_startup_hook_type PreviousShmemStartupHook;
 
+static nodemask_t lastKnownMatrix[MAX_NODES];
 
 static void MtmExecutorFinish(QueryDesc *queryDesc);
 static void MtmProcessUtility(Node *parsetree, const char *queryString,
@@ -1552,7 +1553,8 @@ static bool
 MtmBuildConnectivityMatrix(nodemask_t* matrix, bool nowait)
 {
 	int i, j, n = Mtm->nAllNodes;
-	fprintf(stderr, "Connectivity matrix:\n");
+	bool changed = false;
+
 	for (i = 0; i < n; i++) { 
 		if (i+1 != MtmNodeId) { 
 			void* data = RaftableGet(psprintf("node-mask-%d", i+1), NULL, NULL, nowait);
@@ -1563,12 +1565,27 @@ MtmBuildConnectivityMatrix(nodemask_t* matrix, bool nowait)
 		} else { 
 			matrix[i] = Mtm->connectivityMask;
 		}
-		for (j = 0; j < n; j++) { 
-			putc(BIT_CHECK(matrix[i], j) ? 'X' : '+', stderr);
+
+		if (lastKnownMatrix[i] != matrix[i])
+		{
+			changed = true;
+			lastKnownMatrix[i] = matrix[i];
 		}
-		putc('\n', stderr);
 	}
-	fputs("-----------------------\n", stderr);
+
+	/* Print matrix if changed */
+	if (changed)
+	{
+		fprintf(stderr, "Connectivity matrix:\n");
+		for (i = 0; i < n; i++)
+		{
+			for (j = 0; j < n; j++)
+				putc(BIT_CHECK(matrix[i], j) ? 'X' : '+', stderr);
+			putc('\n', stderr);
+		}
+		fputs("-----------------------\n", stderr);
+	}
+
 	/* make matrix symetric: required for Bron–Kerbosch algorithm */
 	for (i = 0; i < n; i++) { 
 		for (j = 0; j < i; j++) { 
@@ -1577,8 +1594,9 @@ MtmBuildConnectivityMatrix(nodemask_t* matrix, bool nowait)
 		}
 		matrix[i] &= ~((nodemask_t)1 << i);
 	}
+
 	return true;
-}	
+}
 
 
 /**
@@ -1599,6 +1617,11 @@ bool MtmRefreshClusterStatus(bool nowait, int testNodeId)
 	}
 
 	clique = MtmFindMaxClique(matrix, Mtm->nAllNodes, &clique_size);
+
+	if ( clique == (~Mtm->disabledNodeMask & (((nodemask_t)1 << Mtm->nAllNodes)-1)) ) 
+		/* Nothing is changed */
+		return false;
+
 	if (clique_size >= Mtm->nAllNodes/2+1) { /* have quorum */
 		fprintf(stderr, "Old mask: ");
 		for (i = 0; i <  Mtm->nAllNodes; i++) { 
@@ -1729,7 +1752,7 @@ void MtmOnNodeDisconnect(int nodeId)
 			}
 		}
 		MtmUnlock();
-	} else { 
+	} else {
 		MtmRefreshClusterStatus(false, 0);
     }
 }