Merge pull request #648 from estolfo/RUBY-959-mongos-disconnect

RUBY-959 Don't remove an unknown mongos from the cluster

Author: estolfo

lib/mongo/cluster/topology/sharded.rb

@@ -184,7 +184,7 @@ def standalone_discovered; self; end
         private
 
         def remove_self?(description, server)
-          description.is_server?(server) && !description.mongos?
+          description.is_server?(server) && !(description.mongos? || description.unknown?)
         end
       end
     end

spec/mongo/cluster/topology/sharded_spec.rb

@@ -106,6 +106,7 @@
       let(:description) do
         double('description').tap do |d|
           allow(d).to receive(:mongos?).and_return(false)
+          allow(d).to receive(:unknown?).and_return(false)
           allow(d).to receive(:is_server?).and_return(true)
         end
       end

spec/support/sdam/sharded/mongos_disconnect.yml

@@ -0,0 +1,104 @@
+description: "Mongos disconnect"
+
+uri: "mongodb://a,b"
+
+phases: [
+
+    {
+        responses: [
+
+                ["a:27017", {
+
+                    ok: 1,
+                    ismaster: true,
+                    msg: "isdbgrid"
+                }],
+
+                ["b:27017", {
+
+                    ok: 1,
+                    ismaster: true,
+                    msg: "isdbgrid"
+                }]
+        ],
+
+        outcome: {
+
+            servers: {
+
+                "a:27017": {
+
+                    type: "Mongos",
+                    setName:
+                },
+
+                "b:27017": {
+
+                    type: "Mongos",
+                    setName:
+                }
+            },
+
+            topologyType: "Sharded",
+            setName:
+        }
+    },
+    {
+        responses: [
+                ["a:27017", {}],  # Hangup.
+        ],
+
+        outcome: {
+
+            servers: {
+
+                "a:27017": {
+
+                    type: "Unknown",
+                    setName:
+                },
+
+                "b:27017": {
+
+                    type: "Mongos",
+                    setName:
+                }
+            },
+
+            topologyType: "Sharded",
+            setName:
+        }
+    },
+    {
+        responses: [
+                # Back in action.
+                ["a:27017", {
+
+                    ok: 1,
+                    ismaster: true,
+                    msg: "isdbgrid"
+                }],
+        ],
+
+        outcome: {
+
+            servers: {
+
+                "a:27017": {
+
+                    type: "Mongos",
+                    setName:
+                },
+
+                "b:27017": {
+
+                    type: "Mongos",
+                    setName:
+                }
+            },
+
+            topologyType: "Sharded",
+            setName:
+        }
+    }
+]