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src/backend/distributed/connection/connection_management.c

@@ -328,6 +328,9 @@ StartNodeUserDatabaseConnection(uint32 flags, const char *hostname, int32 port,
 														 sizeof(MultiConnection));
 	dlist_push_tail(entry->connections, &connection->connectionNode);
 
+	/* these two flags are by nature cannot happen at the same time */
+	Assert((flags & OPTIONAL_CONNECTION) && (flags & WAIT_FOR_CONNECTION));
+
 	if (flags & WAIT_FOR_CONNECTION)
 	{
 		WaitLoopForSharedConnection(hostname, port);

src/backend/distributed/connection/shared_connection_stats.c

@@ -288,9 +288,9 @@ WaitLoopForSharedConnection(const char *hostname, int port)
  * connection counter for the given nodeId and the current database in
  * SharedConnStatsHash.
  *
- * The function first checks whether the number of connections is less than
- * citus.max_shared_pool_size. If so, the function increments the counter
- * by one and returns true. Else, the function returns false.
+ * If the function returns true, the caller is allowed (and expected)
+ * to establish a new connection to the given node. Else, the caller
+ * is not allowed to establish a new connection.
  */
 bool
 TryToIncrementSharedConnectionCounter(const char *hostname, int port)