JAVA-2578: The logicSessionTimeoutMinutes should be the minimum of all reporting servers

Author: jyemin

driver-core/src/main/com/mongodb/connection/ClusterDescription.java

@@ -184,7 +184,11 @@ public boolean apply(final ServerDescription serverDescription) {
             if (cur.getLogicalSessionTimeoutMinutes() == null) {
                 return null;
             }
-            retVal = cur.getLogicalSessionTimeoutMinutes();
+            if (retVal == null) {
+                retVal = cur.getLogicalSessionTimeoutMinutes();
+            } else {
+                retVal = Math.min(retVal, cur.getLogicalSessionTimeoutMinutes());
+            }
         }
         return retVal;
     }

driver-core/src/test/unit/com/mongodb/connection/ClusterDescriptionTest.java

@@ -231,6 +231,76 @@ public void clusterDescriptionWithCompatibleServerShouldBeCompatible() throws Un
         assertTrue(description.isCompatibleWithDriver());
     }
 
+    @Test
+    public void testLogicalSessionTimeoutMinutes() {
+        ClusterDescription description = new ClusterDescription(MULTIPLE, REPLICA_SET, asList(
+                builder().state(CONNECTING)
+                        .address(new ServerAddress("loc:27017")).build()
+        ));
+        assertEquals(null, description.getLogicalSessionTimeoutMinutes());
+
+        description = new ClusterDescription(MULTIPLE, REPLICA_SET, asList(
+                builder().state(CONNECTED)
+                        .address(new ServerAddress("loc:27017"))
+                        .build()
+        ));
+        assertEquals(null, description.getLogicalSessionTimeoutMinutes());
+
+        description = new ClusterDescription(MULTIPLE, REPLICA_SET, asList(
+                builder().state(CONNECTED)
+                        .ok(true)
+                        .address(new ServerAddress("loc:27017"))
+                        .build()
+        ));
+        assertEquals(null, description.getLogicalSessionTimeoutMinutes());
+
+        description = new ClusterDescription(MULTIPLE, REPLICA_SET, asList(
+                builder().state(CONNECTED)
+                        .ok(true)
+                        .address(new ServerAddress("loc:27017"))
+                        .logicalSessionTimeoutMinutes(5)
+                        .build(),
+                builder().state(CONNECTING)
+                        .address(new ServerAddress("loc:27018"))
+                        .build()
+        ));
+        assertEquals(new Integer(5), description.getLogicalSessionTimeoutMinutes());
+
+        description = new ClusterDescription(MULTIPLE, REPLICA_SET, asList(
+                builder().state(CONNECTED)
+                        .ok(true)
+                        .address(new ServerAddress("loc:27017"))
+                        .logicalSessionTimeoutMinutes(5)
+                        .build(),
+                builder().state(CONNECTED)
+                        .ok(true)
+                        .address(new ServerAddress("loc:27018"))
+                        .logicalSessionTimeoutMinutes(3)
+                        .build(),
+                builder().state(CONNECTING)
+                        .address(new ServerAddress("loc:27017"))
+                        .build()
+        ));
+        assertEquals(new Integer(3), description.getLogicalSessionTimeoutMinutes());
+
+        description = new ClusterDescription(MULTIPLE, REPLICA_SET, asList(
+                builder().state(CONNECTED)
+                        .ok(true)
+                        .address(new ServerAddress("loc:27017"))
+                        .logicalSessionTimeoutMinutes(3)
+                        .build(),
+                builder().state(CONNECTED)
+                        .ok(true)
+                        .address(new ServerAddress("loc:27018"))
+                        .logicalSessionTimeoutMinutes(5)
+                        .build(),
+                builder().state(CONNECTING)
+                        .address(new ServerAddress("loc:27017"))
+                        .build()
+        ));
+        assertEquals(new Integer(3), description.getLogicalSessionTimeoutMinutes());
+    }
+
     @Test
     public void testObjectOverrides() throws UnknownHostException {
         ClusterDescription description =