To work around an issue with three-config server sharded clusters, added _id to documents inserted into system.users collection on pre-2.6 MongoDB servers.

 JAVA-1794

Author: jyemin

driver-core/src/main/com/mongodb/operation/CreateUserOperation.java

@@ -38,7 +38,7 @@
 import static com.mongodb.operation.OperationHelper.releasingCallback;
 import static com.mongodb.operation.OperationHelper.serverIsAtLeastVersionTwoDotSix;
 import static com.mongodb.operation.OperationHelper.withConnection;
-import static com.mongodb.operation.UserOperationHelper.asCollectionDocument;
+import static com.mongodb.operation.UserOperationHelper.asCollectionInsertDocument;
 import static com.mongodb.operation.UserOperationHelper.asCommandDocument;
 import static java.util.Arrays.asList;
 
@@ -122,7 +122,7 @@ public void onResult(final WriteConcernResult result, final Throwable t) {
     }
 
     private InsertRequest getInsertRequest() {
-        return new InsertRequest(asCollectionDocument(credential, readOnly));
+        return new InsertRequest(asCollectionInsertDocument(credential, readOnly));
     }
 
     private MongoNamespace getNamespace() {

driver-core/src/main/com/mongodb/operation/UpdateUserOperation.java

@@ -39,8 +39,8 @@
 import static com.mongodb.operation.OperationHelper.releasingCallback;
 import static com.mongodb.operation.OperationHelper.serverIsAtLeastVersionTwoDotSix;
 import static com.mongodb.operation.OperationHelper.withConnection;
-import static com.mongodb.operation.UserOperationHelper.asCollectionDocument;
 import static com.mongodb.operation.UserOperationHelper.asCollectionQueryDocument;
+import static com.mongodb.operation.UserOperationHelper.asCollectionUpdateDocument;
 import static com.mongodb.operation.UserOperationHelper.asCommandDocument;
 import static java.util.Arrays.asList;
 
@@ -124,7 +124,7 @@ public void onResult(final WriteConcernResult result, final Throwable t) {
     }
 
     private UpdateRequest getUpdateRequest() {
-        return new UpdateRequest(asCollectionQueryDocument(credential), asCollectionDocument(credential, readOnly),
+        return new UpdateRequest(asCollectionQueryDocument(credential), asCollectionUpdateDocument(credential, readOnly),
                                  WriteRequest.Type.REPLACE);
     }
 

driver-core/src/main/com/mongodb/operation/UserOperationHelper.java

@@ -20,8 +20,10 @@
 import org.bson.BsonArray;
 import org.bson.BsonBoolean;
 import org.bson.BsonDocument;
+import org.bson.BsonObjectId;
 import org.bson.BsonString;
 import org.bson.BsonValue;
+import org.bson.types.ObjectId;
 
 import java.util.Arrays;
 
@@ -48,12 +50,15 @@ static BsonDocument asCollectionQueryDocument(final MongoCredential credential)
         return new BsonDocument("user", new BsonString(credential.getUserName()));
     }
 
-    static BsonDocument asCollectionDocument(final MongoCredential credential, final boolean readOnly) {
-        BsonDocument document = asCollectionQueryDocument(credential);
-        document.put("pwd", new BsonString(createAuthenticationHash(credential.getUserName(),
-                                                                    credential.getPassword())));
-        document.put("readOnly", BsonBoolean.valueOf(readOnly));
-        return document;
+    static BsonDocument asCollectionUpdateDocument(final MongoCredential credential, final boolean readOnly) {
+        return asCollectionQueryDocument(credential)
+               .append("pwd", new BsonString(createAuthenticationHash(credential.getUserName(), credential.getPassword())))
+               .append("readOnly", BsonBoolean.valueOf(readOnly));
+    }
+
+    static BsonDocument asCollectionInsertDocument(final MongoCredential credential, final boolean readOnly) {
+        return asCollectionUpdateDocument(credential, readOnly)
+               .append("_id", new BsonObjectId(new ObjectId()));
     }
 
     private UserOperationHelper() {